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FAQs on the Molly Systems/Maintenance

Related Articles: Mollies, & Poeciliids: Guppies, Platies, Swordtails, Mollies by Neale Monks, Livebearing Fishes by Bob Fenner,

Related FAQs: Mollies 1, Mollies 2, Molly Identification FAQs, Molly Behavior FAQs, Molly Compatibility FAQs, Molly Selection FAQs, Molly Feeding FAQs, Molly Disease FAQs, Molly Reproduction FAQs, Livebearers, Guppies, Platies, Swordtails,

Need hard, alkaline water, many times with a modicum of salts... NO ammonia, NO nitrite, LITTLE Nitrate... and a dearth of metabolite concentration.

Brackish water for Black Mollies      5/4/15
Hi. I'm keeping black mollies in a 20 gallon (76 litres) tank. After reading various articles on your site re: mollies, brackish water, salinity, I was very impressed & began to add marine salt to my tank. I like the fact that the brackish water helps ward off parasites & fungi & is inherent to good molly health. I am seeing the benefit to them with my own eyes.
<Cool. While brackish conditions aren't essential, it does make keeping this species easier.>
I've read your recommendation of an SG=1.004-1.006 being fine for black mollies but was wondering if I could go as high as 1/2 seawater = 1.012 without adversely affecting the biological filter/balance?
<No, this isn't a good idea. The Mollies will be fine. But the filter bacteria in tanks maintained around SG 1.003-1.004 aren't the ones at SG 1.010-1.012, which I believe are the marine, not freshwater, species of bacteria.
Whatever the science, the practical facts are that as you raise salinity, filtration suffers, and you get a "mini cycle" that lasts a couple of weeks, sometimes longer, as a new, higher salinity biological filter develops. While nothing the Mollies won't handle (they used to be used to mature marine aquaria, and are much hardier in saline than freshwater conditions) there's no real advantage to you. Indeed, SG 1.003 would be optimal for Mollies. Cheap, easy to produce (1 level teaspoon of salt per 2 litres of water) and every bit as effective in terms of preventative healthcare.>
Also is it ok for molly fry to be born in brackish water or is it better they be born in freshwater & gradually acclimated to brackish water?
<Any and all of these options are fine.
Mollies are euryhaline, even as fry. You can move them from freshwater to saltwater and back again, as required. As/when you visit the Caribbean coastline and islands, you'll be amazed how common Mollies are in lagoons, estuaries, and shallow creeks just a few meters inland from the sea. They're also found dozens of miles inland as well, in plain freshwater.>
Thank you for your help.
Richard V.
<Most welcome. Neale.>

Help my Dalmatian molly is swimming funny and guppy problems        3/25/16
I have 1 male Dalmatian molly and 1 female gray molly, 1 lyretail molly,
and 4 cobra guppies. My Dalmatian molly is swimming as though he can't use his tail, so he's only swimming with his front fins, this hasn't happened to any of my other fish. His tail, I don't know if this helps, but his tail colors, where it is white, looks sort of bluish. What should I do to help him use his tail again?
<This sounds like the Shimmies. It's a neurological disorder brought about by environmental stress. No treatment, but it will get better if the environment improves.
So, let's recap what Mollies want. Firstly, space. At least 100 litres/25 gallons. Next up, high hardness and a basic pH. Liquid rock is ideal! Aim for 15+ degrees dH, pH 7.5-8.2 and you'll be doing fine.
Thirdly, low nitrate. They are extremely sensitive to this compared to many other common fish. Anything above 20 mg/l will stress them in freshwater conditions, and nitrate should certainly not be above 40 mg/l. And finally,
salt. This isn't 100% essential if you have a high hardness and minimal nitrate, but if you don't, adding marine aquarium salt is crucial.
Something like 5-6 gram per litre (about 4 teaspoons per US gal) is an ideal starting point, but really anything up to full strength seawater (35 gram/litre) is fine. Do note of course that most freshwater fish won't tolerate salt well. Guppies and other livebearers will thrive at the 5-6 gram/litre salinity, but things like barbs, Corydoras, etc. won't. Most plants aren't happy about salt either, though some species, including Java ferns, Vallisneria and Anubias will all be just fine at this level of salinity. Do your research and act accordingly.>
Another question, I had 2 red cobra guppies, all of which I thought were male, but one of their abdomens were growing and a dark spot was appearing on it's lower abdomen, which made me think it was pregnant, but it soon died. My other red cobra guppies abdomen is starting to grow, do you think it's going to die? or do you believe it's pregnant, I have my doubts.
<Pregnant Guppies are usually distinctive in shape, and in other ways behave totally normally. Since gestation is about a month, you should see females recover their normal, non-pregnant shape quite quickly. Just to remind you, the "gravid spot" isn't a patch of colour that develops in the skin, it's simply the uterus pressing against the skin and thin muscles of the abdomen around the vent, to such a degree you can even see the baby fish when they're close to being born. Obviously, only females ever become pregnant, so if you have males swelling up as well, then something's amiss.
For what it's worth, the use of marine aquarium salt as outlined for Mollies will de-stress Guppies as well, and they're often farmed in slightly brackish water precisely because it reduces the risk of disease.
It's not a cure-all, and if yours have worms, Hexamita infections, or whatever you'll need to medicate accordingly. But if they're simply suffering environmental stress, marine aquarium salt is useful. One last thing: double check you've got at least twice as many females as males if you're keeping both sexes together. Male Mollies and Guppies are highly aggressive towards each other and very, very demanding towards the females.
So the more females, the happier everyone in the tank will be. This rule holds true for all types of livebearers, by the way, not just Mollies and Guppies. Cheers, Neale.>
re: Help my Dalmatian molly is swimming funny and guppy problems     3/26/16

Ok so far with what you have said it's already done, my pH is 7.6, my nitrite and nitrate levels are 0,
<Something wrong here. Zero level nitrate is all but impossible. Even the ocean has measurable nitrate! So go back and use your test kits again, then write back. Perhaps use another test kit... will make the observation those
dip-strips are, at best, approximate.>
and there is aquarium salt in the water.
<Marine aquarium salt. Not freshwater salt, sometimes called aquarium salt.
What's the difference? Plain vanilla tonic salt, of the kind sold to freshwater aquarists, is basically sodium chloride, cooking salt without the iodine. Marine aquarium salt is a whole mixture of minerals including sodium chloride but also, crucially, calcium carbonate, which raises the carbonate hardness (as the name suggests!) which in turn buffers against pH changes. Aquarium salt, or tonic salt, is really used only for treating Whitespot, where it makes a useful way to raise salinity without raising pH or hardness, and that's very important if you're keeping tetras and other species that dislike high hardness. So it's a temporary addition to the tank for use across a couple weeks. Marine aquarium salt, on the other hand, is something used to create specific water conditions. It's used long term, perhaps indefinitely in the case of livebearers. There's really no comparison, but unfortunately retailers are more than happy to sell aquarium salt as a (bogus) cure-all to less experienced aquarists, along with 10 gallon tanks, tea-tree oil, and other things that have little/no value in the hobby. With all this said, if you have the aquarium salt now, using it alongside baking soda can create a reasonable alternative. If you add about 5-6 gram (1 teaspoon) baking soda alongside each 5-6 gram (1 teaspoon) of aquarium salt, you should get about the right ratio. Use your test kit to check if you're unsure, or better yet, set the aquarium salt to one side and just use the marine salt mix (generic brands from PetCo and the like are fine). Let me know what your existing hardness level is before
you do anything though. Stating the pH is actually pretty unhelpful even though pH is something lots of people remember from school. Hardness is the thing that affects fish; not pH. Fish react to changes in pH, yes, but so
long as its stable, most freshwater species have a wide pH tolerance.>
I will research the shimmies further more, thank you, but is there a book that has all the aquarium fresh water fish and there diseases and cures?
<There are some excellent books out there. I think the easiest to read and understand is probably "The Interpet Manual of Fish Health" even though it was written over 20 years ago. It covers all the basics, explains the importance of water chemistry and quality, and offers up useful treatments alongside plenty of nice and clear photos. Being an old book, secondhand copies can be had for pennies. But a lot of books on the topic have been written over the years, and I'd encourage you to visit your local bookstore or library, have a peruse, and see which one appeals to you. In any event, the Shimmies is rock-solid in our understanding, and is almost always a symptom of environmental stress. To save me rehashing what I've written before, let me direct you to an article on the subject I wrote for FishChannel.com a while back...
Basically, it goes away providing you fish the fish's environment. Your problem is to identify what's wrong with the environment before the fish <?>

Excerpted from: Five Almost Perfect Fishes; Great fish for the community aquarium, except for one little thing by Neale Monks

Black mollies, Poecilia hybrids

The good: Hardy, friendly fish full of charm, they even eat algae!

The bad: Needs hard, alkaline water

Top of my list of almost perfect fish has to be the black molly. It's a spectacular fish when kept in a planted tank, the velvety black making a bold contrast with the green leaves. Even with more brightly coloured fish, it holds its own, and makes a superb companion for things like fancy platies and swordtails. Few other freshwater fish are as jet black as these mollies, and most of them are nocturnal. Even cichlids keepers -- usually spoiled for choice when it comes to colours -- don't have anything like the black molly; it's a truly unique fish. Like people, the physically most attractive fish aren't always the ones with the nicest personalities, but the black molly is every bit as friendly as it is beautiful. They won't even harm livebearer fry. Despite their peaceable natures mollies are remarkably bold, and will settle into a new aquarium almost at once, making them great dither fish for encouraging more nervous fish like cichlids and gouramis to come out from their hiding places. It gets even better -- mollies are very tolerant of nitrites, making them an excellent choice for maturing new tanks. Provided you don't overfeed them, they'll handle the entire filter maturation process without any problems; they are particularly valued in this regard by marine aquarists who use them instead of more delicate (and expensive) reef species. The icing on the cake is that mollies are fond of algae, and will happily graze on any green and thread algae in the aquarium. While certainly not in the same league as plecs or Siamese algae eaters (Crossocheilus siamensis), they do have an impact, and are especially good at cleaning delicate leaves where the larger, clumsier species can't reach.

Really, the only shortcoming to the black molly is its need for hard, alkaline water. Of course, this isn't really a problem for aquarists in the South East, and is in fact something of a plus. Unlike all those neons and dwarf cichlids that demand soft and acidic water to do well, here's one fish that just loves standard issue London tap water. However, if you are keeping a soft water aquarium or have a planted tank with CO2 fertilisation, chances are the hardness and pH will be too low for the black molly. Ideally, this molly wants a pH of at least 7.5 and the water does need to be at least moderately hard. The addition of salt isn't strictly necessary, but many people have found that it does help to keep mollies healthy and free of diseases like fungus and fin-rot; in this case, raising the specific gravity to around 1.002-1.005 will do the trick nicely and allow you to mix in a few brackish water fish as well.

Chemiblue... carbon use; molly sys.        1/24/15
Hello, I'm new to having a fresh water tank I'm very confused about what is Good and what is Not... I have been to several pet stores regarding what to yse and not. Just to have me spending money I didn't need.
<Quite so. And starting with a 20 gallon tank was a very good move. Smaller tanks usually work out as expensive in the long run.>
My question is I have a 20 gallon tank I purchased 3 Mollie fish as well as a heater, thermometer.
<Mollies are less easy to keep than many people think. Hardy in brackish water, delicate in freshwater. Do read here:
Buying a box of aquarium salt and using a teaspoon or two per gallon can be extremely helpful.>
I asked what size heater do a 20 gallon tank requires. He insisted I buy a 100 watts for it and know I'm seeing moisture around the sides if the tank I feel as though it's too HOT for the fish but the water seems okay. Please
I would just like for someone to be honest and helping me.
<Essentially, you choose the heater depending on two things: size of the tank and how cold the room is. Most aquaria need to be maintained at 25 C/77 F, which will normally be around 5-10 degrees C warmer than the room. The colder the room, the harder the heater has to work, hence the higher the wattage. Similarly, the bigger the tank, the higher the wattage needs
to be. Combine the two and you see the need for heaters of lots of different sizes. Getting a heater slightly too big for your tank is never a problem, it simply switches off most of the time. But getting a heater that's too small is a major problem though as the tank will never heat up properly. So while you have a bit of latitude, it's best to err on the side of getting a heater slightly bigger rather than slightly smaller. At the back of the packaging of the heater, it will state what size tanks the
heater is designed for. As mentioned earlier, if the tank is in a cold room, the heater will have to work harder than normal, so get the heater that's "next size up" in the range for your tank. But normally, what the manufacturer states is reliable. If you visit the Eheim website for example, you can download the manuals for their excellent (and good value) heaters, here:
On page 2 they state that for a 20 US gallon tank, their 75 W heater will do the trick.>
I love fish and would like to become better with knowing how to care for them. I had 3 gold fish which died. Asking for some kinda of knowledge regarding this.
Also, it Chemi-Blue safe for a fresh water tank I have 3 Mollie's. Will I have to replace my filter with that I'm confused?
<Chemi-Blue is a brand of carbon. It's perfectly safe in freshwater tanks, but not really necessary. For one thing, it removes medications, so you'd need to remove the carbon any time you treat your fish. It also needs replacing every 2-3 weeks otherwise it's just a waste of space.>
Thank you,
<Welcome. Neale.>

Changing Mollies Environment    7/27/12
Hello. I read your site daily to see if any new information has cropped up for me to absorb. I just love mollies. I am addicted to them. Right now I have 2 short Finned Dalmatian Lyretail Mollies and 5 fry. I was reading a little bit about other fishes and I came across a couple of opinions on Bettas and I was wondering how this may relate to Mollies.
<They relate badly! Mollies are infinitely better kept in an aquarium tailored to their needs. At the very least, that's a tank with rock hard water and plenty of algae. They also need superb water quality, especially if kept in freshwater conditions (to some degree they're less sensitive when kept in slightly brackish water). Because Mollies can be disease-prone when kept in freshwater conditions, especially if water quality isn't top-notch, having the option of adding a little marine aquarium mix, even as little as 2-3 grams/litre (0.3-0.5 oz/gal), is well worth considering.
While that's a trivial expense compared to the savings you'll make on fish medicines, even a little salt would stress freshwater-only species like Bettas. Hence, Mollies are best kept alone or with fish that tolerate a little salt (such as Australian Rainbowfish) so if you do choose to add salt, your other fish won't mind. In any case, Mollies are so varied and so colourful, you could keep a tank of just Mollies and not get bored.>
I haven't been able to find the answer. The opinion is that since Bettas are such curious fish it is a good idea to change up their environment every month to two months. Will doing this stress out my Mollies. i.e.: Do Mollies like a constant environment or one that changes.
<See above. Moving rocks about isn't going to bother the Mollies. As for the Bettas, moving the rocks about doesn't do much to help them either, and the idea Bettas are unusually smart or stimulated by moving things about makes no biological sense at all. In the wild (male) Bettas hold territories and don't stray far from them, and if you move the rocks and plants, the Bettas loses its territory and has to go about exploring again and identifying territorial boundaries, all of which will be, if not stressful, then at least unnecessary. Just because a Betta is more active afterwards doesn't mean it's happier, and this sort of fuzzy thinking is precisely the sort of nonsense that blights the Betta side of the hobby. Bettas aren't little people, and assuming they think like people isn't fair on the fish. It'd be nice if there was less talk about making Bettas happy by adding toys and such, and more understanding that Bettas need a proper aquarium of decent size, proper filtration, and adequate heating. I think you'd be shocked at how many messages we get from people who clearly love their Bettas but have no real idea about what Bettas need to stay healthy.
It's a lot like how people love their dogs and give them toys and designer clothes but don't take their dogs out for long walks twice a day and don't allow the dog to socialise with other dogs.>
I have a second set of plants and ornaments that I could use to switch it up with. I would NOT be changing water parameters or gravel or equipment, just aesthetic things. Thank you for taking the time to answer such a silly question and thank you for such a wonderful site on Mollies.
<Not a silly question at all; a very perceptive one. It's good to think about these things up front.>
<Cheers, Neale.>

Bristlenose Pleco and Mollies   4/1/12
Hi everyone, very informative site here. I've looked over it a few times and haven't found much on my particular situation, so I thought I'd shoot you all an email. I apologize if this has been addressed already and I missed it.
<Is indeed written elsewhere on this site. Start here:
Your aquarium is too small, and your water chemistry all wrong, for successful Molly keeping. These Mollies have little chance of long-term success.>
My boyfriend and I have a 10g freshwater tank set up, and for several months had a few ghost shrimp and just a small (about 1.5 inches)
Bristlenose Pleco. The ghost shrimp are now gone, and we recently added a Dalmatian Molly and a silver lyretail Molly.
<See above; a terrible choice for soft, acidic water conditions.>
Our Pleco doesn't seem interested in algae wafers (and there is no algae in the tank) so we feed him a slice of cucumber every few days, which he loves. The mollies nibble at this too, but mostly they are fed with flake food once a day.
The tank is at 0 nitrite, 0 ammonia, about 6.5 pH, between 0 and 40 KH, between 0 and 30 GH, and about 74/76 degrees Fahrenheit (sorry for the approximations, we only have the API test strips right now and they include a good amount of eyeballing). The nitrate levels have gone up since adding the mollies. It used to hover around 10, and is now going up to 30 and 40.
We have been doing 20% water changes, which decreases the nitrate for a bit, but within the next 24 hours it rises again.
So, my question is really more general. Of course I would like to know if we should be doing anything differently to reduce the nitrates further, but mainly I would like to know how to ensure that this environment is going to be beneficial to both types of fish. Are the water parameters good as they are,
or should they be altered?
I have read different things about what each fish needs, and would like to be sure I am providing an environment that is a good compromise to the needs of each species, so they can all coexist happily.
<Mollies don't compromise. You either give them what they want, or they die. They really do need hard, alkaline water -- and ideally slightly brackish water at that.>
Thanks in advance, and I apologize for such a long query. We love our fish very much, as I'm sure you all do as well. Best wishes,
<Glad to help, and good luck. Neale.>
Re: Bristlenose Pleco and Mollies   4/2/12

Thanks so much Neale for the advice. I'll be sure to rectify the situation so everybody fares well. I see another tank in our near future.
<Ah yes, multiple tank syndrome… no known cure!>
Thanks again for the quick response,
<Happy to help. Neale.>

Mollies and nitrites contradiction   3/18/12
I was reading your page on mollies and came across two contradictory statements. In the article To salt or not to salt, it says " Mollies do appear to be particularly sensitive to nitrite and nitrate, despite their widespread sale as beginner fish. In the next article excerpted from " Five almost perfect fish...." , it says  "Mollies are very tolerant of nitrites, making them an excellent choice for maturing new tanks.". I have a maturing tank and am wondering whether or not I should add some Mollies.
<Hello Lara. Mollies are nitrite tolerant in saltwater and moderately brackish water aquaria. They are extremely nitrite intolerant in freshwater aquaria. I'll need to go back and correct this in the article if it isn't clear. So if you're setting up a reef tank or some other saline system, then Black Mollies can be a worthwhile way to cycle the filter. If a freshwater system, avoid. Cheers, Neale.>

Molly Advice Please, sys. 12/7/11
Hello there
First of all I just wanted to say thank you for such a helpful website, it clearly takes time and effort to achieve such a comprehensive site, and its appreciated a great deal.
<Thanks for the kind words.>
I have a 60L tank, with 2 upside down catfish, 2 blue gourami's, and 2 red blood mollies (1m, 1F). The male is harassing the female, so today I went out and bought 3 more female red blood mollies. But when I got back from the pet shop, the female molly was so unwell it looks as though she won't last the night. All the other fish are totally fine, and I do regular water changes (every 3-4 weeks). No other signs of unwellness, no ick or disease is in the tank.
My question is, how can I save the harassed molly? I know it may be too late in the day (lesson well learned for me), but I want to save her if I can. Look forward to your expert advice and any help that can be given.
<Your real problems here are these: Firstly, the tank is too small. Mollies are aggressive, as you're learning, and I wouldn't keep them in anything smaller than 100 litres. Removing the male could help, returning him to the pet store. The second problem is that Mollies must have hard, alkaline water (which your Gouramis won't appreciate or the Catfish). Ideally, they would be kept in slightly brackish water, with 5-6 grammes of marine aquarium salt mix per litre (and this'd kill your Gouramis and Catfish). In brackish water your female Molly would probably recover under her own steam if the male was removed. But in freshwater, especially freshwater that isn't very hard, these are sensitive fish.>
Thank you so much in advance.
<Do read:
Cheers, Neale.>
Re: Molly Advice Please 12/7/11

Thank you so much for the advice and quick response. The harassed molly has lived to tell another day, albeit still quiet but she is eating and swimming more now :)
<Good. Do you have a breeding trap? You could confine the MALE for a few days in there. Sometimes that takes the edge off an aggressive male, and will allow the other fish time to rest and feed. In theory, one male and 3-4 females should be fine, but your tank is a bit small, so there's a lack of space for females to get away from the male.>
I think I will take the male back to the pet shop and re think a new home for the females.
Thanks again for your advice and patience, it really is very much appreciated.
<My pleasure.>
Kindest regards
<Likewise to you, Neale.>
Re: Molly Advice Please 12/7/11

Thanks again Neale, I'll confine the naughty male and see if that works, if not, I'll re home him. (I won't stand for domestic violence in my tank lol)
<Well, sexual harassment is a wrong, even if you're a fish!>
Very much appreciate your advice. Hope you have a good evening.
<Sick with cold, but will try.>
<Cheers, Neale.>
Re: Molly Advice Please 12/8/11

Sorry your not well, there are far too many germs going round at the moment
<Probably just "man flu".>
He still was harassing the other ladies in the tank, so I took him to a friends restaurant and put him (no, not on the menu!) in their tank. its at least 500L job that was custom built. Obviously plenty of room in there, and he looks tiny in comparison to the other fish, but seems happy enough
<Sounds perfect.>
Thanks again for all the advice & support, greatly appreciated.
<Happy to help.>
Hope you feel better as soon as poss.
<Best wishes, Neale.>

Re: question about Ick.... 8/28/11
I did read this article... it is in fact the only one I saw mention the difficulties in raising mollies... especially for novices. That is when I realised if our 3rd one passed (which it did) we would not seek another molly.....
thank you again for all your help.
<As/when you decide to keep Mollies -- and they are lovely fish in many ways -- simply set up a slightly brackish aquarium just for them! It's easy, and when kept that way, they're extremely hardy. In the past marine aquarists used to use Mollies to cycle their saltwater tanks. Black Mollies thrive in seawater, and they're completely bullet-proof when kept in marine conditions, going through the whole cycling process with barely a scratch!
Cheers, Neale.>

Like to make a few changes to my 55 gal molly tank 3/1/11
Hello WWM Crew,
I have a 55 gallon tank, at which this is my Mollie only tank. Back in October 2010 I started to convert this tank from FW to BW. At the current SG level my mollies doesn't breed as often, and if any females get pregnant it's usually 2 adult females. My current ratio is 1:3 so there's 13 males and 39 females. The salt I use is IO (Instant Ocean), And I do have a refractometer. So I can keep the SG in check when I do my weekly
My weekly maintenance is water check (PH, Ammonia, Nitrite and Nitrate), with a 25% water change. for the past month my SG would fluctuate a little bit between 1.015 - 1.017. Now I have a 38 gallon tank to use as a nursery for the fry's after it finish cycling. I would want to bring the SG down from 1.015 - 1.017 down to around 1.004 - 1.006.
<Yes, sounds ideal. For Mollies, SG 1.002-1.003 is ample, and will allow lots of plant species as well as numerous companion fish options.>
I know I would need to do this slowly, but not sure how much salt to reduce weekly or bi-weekly?
<A good plan is to drop one "point" on the SG scale every water change, i.e., if you have 1.015 now, add 20% 1.014 the next water change, and than 1.013 the next water change, 1.012 after that, and so on. Do a nitrite test every couple of weeks to check everything is okay. Between the jigs and the reels you should find the bacteria in the filter adjust.>
I also been reading on WWM that because of the weekly water changes that charcoal, might not be a good thing.
<In most aquaria carbon doesn't do much. Carbon removes organic chemicals that accumulate in old water that make the water yellow and more acidic. If you're doing water changes, you're minimising that anyway. Because carbon removes medications, it's risky to leave in filters because sometimes you try to medicate fish and forget the carbon is there, and wonder why the fish don't get better!>
If so what can be use?
<In the modern freshwater hobby, it really doesn't have much use. But decades ago people avoided water changes, so carbon helped keep the water looking clean.>
At this time I have a Penn Plax cascade 300 power filter ( not happy with it ) I done mod on the intake side and happy with the results, but I will have a canister this summer. Until then this power filter has to work.
Tank temp ... temp maintains 77.7 to 79.5. during the daytime hours it's 79 and during the night the lowest it drops to 77.7. My lights are on a timer they come on every day at 1pm and go off at 8:30pm.
<Sounds fine.>
<Cheers, Neale.>

Mollies, gen. Incomp. w/ ADFs 1/28/11
Hi! I started a 14 gal freshwater tropical tank about 3 wks ago.
<Ah, this tank is a bit small for Mollies. Even if they live in the sense of water quality being adequate, maintaining the low levels of nitrate will be hard, and males will fight in such a small tank. For reliable results, treat 30 gallons as the minimum for Mollies.>
I started with two male balloon-bellied mollies, then added two ADF's over the next couple of weeks (since I didn't know that mollies prefer brackish conditions).
They seem to be doing fine.
<As they often do for weeks or months. The problem with Mollies is that they tend to become sickly over the long term kept in freshwater. Not always by any means, but easily 50% of the time. Hence the recommendation that Mollies be kept in their own tank, where water chemistry can be tweaked as required. They aren't good companions for frogs.>
I just have a few questions....(I don't trust PetSmart anymore) 1. I originally wanted to add more mollies to the tank, but reading info on mollies has made me think this would not be a good idea, as adding more male mollies would cause aggression problems, and I don't have the room to add enough female mollies for my two males, is this true?
<Is true. In 14 gallons you'd be lucky to keep one male and two females safely. Two females or three females even might be fine. But that's it.>
And if I do have room to add more fish, how many and what kind could I add comfortably?
<Do read up about what Mollies need, and then ask your question again once you've short-listed some species that get on with Mollies.>
2. The two mollies I have now are active and eat well, so I'm assuming their freshwater (with no aquarium salt) environment is ok,
<Don't bank on it. It's a crap shoot. Simple as that.>
since I have the two ADF's....is this true?
<Not true at all. Mollies and Frogs are poor choices for tankmates.>
3. I use a turkey baster to feed my ADF's at the bottom of the tank, and it still seems like they don't eat that much. How much should I expect to see them eating?
<Not a huge amount, but easily enough ever second day to slightly round out their bellies. Wet-frozen bloodworms are ideal "starter" foods. Once settled they eat a wide range of things, but variety is important, and dried foods should be used sparingly.>
4. Does water conditioner or AmmoLock ever cause pH readings to be off?
<Shouldn't do this, no.>
My pH fell from around 7 to between 5 and 6 after doing a 50% water change (the ammonia level in my tank had spiked) but my fish seem ok and that was like, 2 wks ago. Should I put some pH conditioner in there as well? I read that messing with pH while a tank is cycling can cause more harm than good.
Thank you very much for your time!-Michelle
<Do read about the needs of these:
Cheers, Neale.>
Re: Mollies 1/28/11
Thank you for your response!
<Glad to help.>
I'm sorry for asking so many questions; I'm new at this, and I'm getting so much conflicting information its difficult to sort through.
<Odd. The needs of Mollies, re: their preference for brackish water, is actually very well known and stated in every book I can think of. While some web sites might suggest otherwise, it's as well to remember the Internet is a hugely unreliable source of information. Always review carefully who says what and why. A retailer will tell you many things, but remember he/she is trying to sell you something too'¦ some retailers are wonderfully honest people, but others, a bit less so.>
So, I plan to separate my ADF's and my mollies; I purchased another small tank today for the ADF's.
<Do read up on the needs of these. Very small tanks, less than 5 gallons, aren't worth using.>
My question now is: What is the best way to go about transferring the frogs into the new tank?
<Divide the existing water out 50/50 between the new tank and the old tank. Move the frogs and Mollies into each tank. Top up both with dechlorinated water. In the case of the Mollies, I strongly recommend adding at least 2 grammes of marine aquarium salt mix per litre of water. Although splitting water does nothing to move bacteria between the two tanks, it will minimise shock through temperature and water chemistry changes.>
My original tank is still cycling, so the pH levels are a little low and the ammonia levels are unstable.
<Salt will help detoxify the nitrite, and this will help the Mollies immensely.>
Should I use some water from the original tank to transfer them into, or should I start over completely and begin cycling this new tank, then put the frogs in once its done cycling?
<You will need to divide the mature filter media between the two tanks. Around 50/50. Done that way, both tanks will be instantly mature. Top up both filters with new media, and that's that! Cheers, Neale.>
Re: Mollies, Aq. salts (FW) f'
Hi! Thanks for being so helpful...a little update and a couple more questions :)'¦.. I put the frogs in a 5 gal tank of their own. Now I'm trying to get the water right in the molly tank. I bought sea salt for it, but PetSmart told me to NOT use sea salt, to use aquarium salt instead.
<What do you mean by "sea salt"? Marine aquarium salt is precisely what you want. Sea salt used for cooking is not. As for generic "aquarium salt" as you'd use in a FRESHWATER aquarium to treat Whitespot is adequate but less useful. Your pet shop clerk is correct you don't want to use cooking sea salt, but absolutely wrong about using marine aquarium salt.>
So I put aquarium salt in my tank...it came in big chunks so I just put the correct amount of tablespoons in the tank, thinking the crystals would dissolve over time.
<No! Do not add salt this way! NEVER, EVER add salt directly to the aquarium.>
So, now how do I get the aquarium salt out to put sea salt in?
<You don't need to.>
Am I going to have to take out the gravel substrate and clean it or should I just wait a little while for the salt to dissolve completely then add sea salt to my water changes?
<Let's start again. Attend carefully! What you want is marine aquarium salt, for example Reef Crystals or Instant Ocean. PetSmart may even have their own generic brand. Ask the clerk for the salt used in marine reef tanks. That's the stuff! A small box shouldn't cost more than $5-10. Now, go home, and weigh out on kitchen scales precisely 5 grammes. That's how much you add to each litre of water IN A BUCKET. It should be a bit under one level teaspoon (which should hold about 6 grammes of marine salt mix). If your bucket holds 15 litres of water, then you add 15 x 5 = 75 grammes. Stir into the water until it's all dissolved. Add that to your aquarium with each water change. So if you take out 15 litres per water change, you add 15 litres of the water and salt mix. If you need to work in non-metric units, the concentration we're doing here is 0.65 ounces per US gallon. It's really very simple. Every time you take some water out, you replace that missing water with a new bucket of water to which JUST THE RIGHT amount of salt has been added FOR THAT BUCKET not the whole tank. Do that, and the water should stay very slightly brackish, about SG 1.002 if you have a hydrometer (well worth getting, a cheap glass one costs $5). If you need to, print this e-mail off, show it to the store clerk, and have them choose the salt mix and the hydrometer for you. Marine aquarium salt mix is BETTER than "aquarium" salt because it contains minerals that raise hardness and steady the pH, both essential to long-term success with Mollies. Hope this clarifies things. Cheers, Neale.>

A second molly tank?? 1/13/11
I have a 20 gallon long tank and just bought a 30 gallon as there was a huge sale at the petstore. I moved my five female mollies into that.
Is a male molly only tank a really bad idea due to their aggression??
<Males will fight with one another, but if kept in a fairly large group, say six or more, you shouldn't find any one of them becomes dominant.>
I'm thinking they will fight as if females were around.
<They fight anyway, females or no females.>
Also I noticed that so many people keep male and female mollies together, but I prefer the peace of an all female molly tank.
<Very wise, and highly recommended in situations where the males and females look very similar.>
I was wondering if people let their mollies breed because they are using them as feeder fish in most cases??
<Some may do, but it's an expensive way to create feeder fish, so not common.>
or does the male female "drama" make fishkeeping more interesting??
<Watching the males raise and lower their Sailfins is certainly interesting, and the reward of having fry to rear can be a bonus. Selling good quality fry isn't usually too hard.>
When people mention making sure the fry are ok I am thinking "My God, where will you put them all?"
<A very fair point. But Mollies do tend to be cannibalistic unless there are lots of floating plants, so you're unlikely to end up with that many fry. In the wild newborn Mollies immediately hide among floating plants, so there's been no reason for adult Mollies to evolve parenting skills. To a Molly, anything small and wriggly at the surface is food, whether baby fish or mosquito larva!>
I also thought of one black Lyretail male molly and four or five female platies together, but that maybe a bad idea also for the 20 gallon??
<Mollies tend to do best kept warmer than Platies, so I wouldn't recommend mixing them. There are Platies of every imaginable colour, and if you're not planning on selling the fry, you can mix and match them freely. Over time cross-bred Platies end up looking like the greenish-blue wild-types, so if you want to keep your Platies looking all one colour over the generations, keep just the one variety.>
Thank you!!!
<Cheers, Neale.>

Real plants and mollies 1/8/11
Hello Again:
<Hi there John>
I was wondering if it is silly to put real plants in with mollies as they are herbivores and probably would eat them, yet people seem to be able to do this??
<Yes... and a good idea too! Just need more plant material than they can consume...>
I was thinking of getting the real plants to offset algae.
<Mmm, not so much. There are many algae species that are unpalatable to Mollies, even some that are outright toxic>
I have five black mollies in a 20 gallon long, once a week water changes When I had Danios they tore the real plants apart
<Some do this>
I was down at the big box fish store today that listed "free snail" on the container with a live plant.
<Heeeee! Or was that supposed to read "Snail free?">
I think a snail would be a nightmare. The dude at another store wanted to sell me a $20 Swordplant then admitted the mollies would tear it apart
<I doubt that any but the largest of mollies, puniest of swords...>
My question is: Is there anyway to keep live plants with herbivore fish. It seems that people do this, but wouldn't the mollies go crazy on them, or do the plant leaves grow back? Is there a certain type of plant they ignore
<The plants can grow faster... they can even be separated by a clear panel (glass, acrylic) from the fishes... or species of plants used that they don't particularly care for (e.g. Ceratophyllum/Coontail) or are too tough (e.g. Anubias...) to destroy.>
Thank You!!!!!
<Welcome! Bob Fenner>
Really easy plants 1/8/11
<Hi there again John>
I was just writing about real plants for all female brackish Molly aquariums. I think it is better to get Amazon Frogbit, as they are low light thick plants and the fish can't tear them apart. I am wondering if I
am right??
<A good choice, yes>
Is Indian fern a low light plant also???
I guess I am looking for low light and lowest maintenance possible
Thank You!!
<You might do well to peruse our Planted Tank Subweb:
and here re Brackish Planted Sys.:
if you're employing much salt for your Mollies.
Bob Fenner>

Problems with my Dalmatian mollies (and I think maybe more that one problem?) 12/27/10
I'm really struggling with my new fish. In the middle of November I set up a new 100L tank. It has gravel, an elite submersible 150W heater set at 26oC, a couple of plastic plants and an Elite jet-flo submersible filter with a zeocarbon cartridge. I added Aqua plus water conditioner and a biological aquarium supplement and let the tank settle for a week before adding 5 sword tails (1 male, 4 females) and 2 silver mollies (one female and one male) and 4 Dalmatian mollies (1 male 3 female). All seemed to be going well. I was instructed to do water changes every couple of weeks, using the same additives in the fresh water. After a couple of weeks one of the female Dalmatian mollies died. I thought nothing of it and put it down
to 'one of those things'. However a couple of weeks after that I lost the male silver molly. This fish was ever so skinny and towards the end just lay on its side. It has always been thin so put that down to being ill
prior to me buying it. Next I lost the other silver female molly. She has been swimming a bit strange, bouncing off items in the tank like she was rubbing herself. I kept a closer eye on the rest from this point onwards as a few to many were now dying. I've had no issues with the sword tails at all. I stopped adding the biological aquarium supplement at this point and introduced a couple of live plants to see if that would help. A couple of weeks after this (still doing regular water changes and adding the tap water conditioner) I lost the male Dalmatian. This was a shock as I thought he was health. Eating well and very active. I took a water sample to the place I bought the fish who informed me that my nitrites were very high and that they thought I had a fungal infection in the tank. I went back home did a 50% water change adding in the biological aquarium supplement and removing the live plants which seemed to do nothing other than make the tank water murky with lots of plant bits floating around. I treated the remaining fish with Protozin. I bought a test kit and kept and eye on the fish. All seemed well again. I bought another 6 Dalmatian mollies. 2 male and 4 female. I had about 2 weeks without any problems. In fact a week ago I found 5 Dalmatian molly fry in the tank who all seem to be doing really well. However, I lost one of my original Dalmatian molly females last night. Like the male silver molly she was very thin even though I saw her
feeding. I constantly test the water the results are always good. The tests last night read pH (7.0), nitrate (<5mg/L), nitrite (<0.1mg/L), NH3 (0mg/L), chlorine (0mg/L), GH (8od ish - dip stick test) and KH (6od ish - dip stick test). I have noticed that one of my new Dalmatian molly females now appears to have a hump just in front of her top fin. It just looks like a generalized swelling from the back of her head to her top fin. She is also swimming a bit erratically at intervals, not all the time. I fear she will dye next. I have started to introduce a bit of aquatic salt (only a bit at a time - I've only added 2 teaspoons) to see if this helps. Do you have any suggestions as to what might be my problem and what I should do? I still have all my sword tails, they seem absolutely fine. Any help would be gratefully received.
<Hello Sarah. Do start by reading here:
Whereas Swordtails are relatively unfussy fish (though they do need to be kept cool, 22-24 C being optimal) Mollies are far more tricky fish to maintain. Exposure to non-zero ammonia and nitrite levels quickly kill them, at least under freshwater conditions, and nitrate levels above 20 mg/l are stressful under freshwater conditions as well. Though some expert aquarists would argue Mollies can be maintained perfectly well in hard, basic freshwater (i.e., 15+ degrees dH, pH 7.5-8.5) it is debatable whether
beginners should ever keep them in freshwater conditions. I'd argue Mollies are easier to keep in slightly brackish water, about 5-6 grammes marine salt mix (not tonic or aquarium salt) per litre being very useful. Most sick Molly issues come down to water quality and water chemistry issues.
Review the needs of these fish and act accordingly. Mollies aren't community fish and should not be kept as such. Cheers, Neale.>
Re: Problems with my Dalmatian mollies (and I think maybe more that one problem?) 12/27/10
Thank you ever so much for getting back to me so quickly on the matter and for providing such useful information. Shop owners should be shot for handing out unsuitable matches of fish especially when they had been asked if the fish were compatible. Anyway that's not the issue now. You say that the sword tails are not as fussy. Could the sword tails survive quite happily in the water if it is brackish or even with a higher saline content? Is there a happy (ish) medium for these two fish? Could you recommend a good book that would provide such useful information so that I don't make such hideous errors in the future. I really want to make a go of my tank and the fish.
Thanks again for you very helpful advise
<Yes, Swordtails will thrive in brackish water. Not strongly saline conditions, but salty enough to make a difference for your Mollies. I'd recommend 2-3 grammes marine salt mix per litre of water. That'll be cheap and easy to produce, will be good for your Mollies, and won't harm your plants or filter bacteria. There are numerous other fish that will tolerate such conditions too: glassfish, blue Acara, Horseface loaches, knight gobies, and so on, so adding livestock to this community, should you want to, wouldn't be hard at all. As for books, do have a read here for some favourites:
The Peter Scott "Complete Aquarium" book is particularly good for people wanting to build community tanks and can be picked up for pennies online as a used book. Cheers, Neale.>
Re: Problems with my Dalmatian mollies (and I think maybe more that one problem?)

Your a star. I'll look for the book you suggested and get to work on the water right away. I'm not going to attempt to obtain other fish until I know I can keep the ones I have but it is great news that this is a
possibility for the future.
Thank you ever so much again. Your advice is invaluable.
Kind regards
<Glad to help, Sarah. Cheers, Neale.>

Black Mollies and "Pea gravel" 12/4/10
<Hello Judy.>
I was wondering if it is ok to keep no more than three female black mollies in a 20 gallon long with no other fish???
<Certainly doable. Assuming these are Shortfin Mollies, they should be okay, especially if you added a wee bit of salt to take the edge off any nitrate toxicity, nitrate, almost as much as soft water, being the thing
that stresses Mollies when kept in small aquaria. Aim for 2-3 grammes/litre.>
Also I have a question about aquarium gravel. The other day we got a 20 pound bag of "pea gravel" for the garden at the hardware store. I was going to use some it for aquarium gravel, but there are all these little sand particles all through it, and I was thinking that may not be good for an undergravel filter. Maybe I should just buy straight aquarium gravel from the fish store.
<Garden gravel is usually fine, and what I use all the time. Provided it is sold as "pond safe", it should be safe.>
I can rinse of some of the sand, but it is impossible to get it all. Would this affect the undergravel filter?? Thank you
<A little sand won't do any harm, but obviously the more crud underneath the undergravel filter plate, the less water will flow through it, so yes, you need to rinse the gravel as best you can.>
<Cheers, Neale.>

Mollies, sys., gen. - 10/09/10
<Hello Amy,>
First, let me thank you for your wonderfully informative site!! It has (and I'm sure will continue to be) extremely helpful.
<Thanks for the kind words.>
I have a few questions about a situation I've found myself in regarding young Dalmatian mollies. An elderly neighbor of mine passed away a few days ago, and this morning, her daughter asked me if I would like to take her mother's mollies, as she is not able to. I only have limited experience keeping simplistic aquariums from when I was a teenager, but the prospect of these mollies being flushed down the toilet has motivated me to attempt to restart my old hobby and save these fish. However, seeing as I in no way want to do more harm that good, I am in need of some advice on a few issues.
<Well, you can start by finding out if someone else can take them. Is there a local fish club? The US is particularly good in this regard, many large cities have vibrant clubs. Alternatively, some stores will take fish and promise to rehome them as best they can. Here in England, the Maidenhead Aquatics chain does this, so there's no risk of them being sold as "feeders". Some animal welfare charities will handle fish too.>
There are nine young (about an inch long) Dalmatian mollies currently in my neighbor's 10 gallon tank. The condition of the tank water (temperature, pH, ammonia, nitrite, nitrate, dH, and kH) is perfect based upon your site's recommendations for mollies (which was a relief), but I know that the tank is entirely too small. I have an empty 36 gallon tank, and my neighbor's daughter has agreed to allow me to keep the mollies in their current tank in her house (with me caring for them) until I can get my tank set up and cycled. Is the 36 gallon tank large enough for all nine mollies, and will the fish be okay in the smaller tank for the few weeks it takes for the larger tank to fully cycle?
<In slightly brackish water, about 6 grammes marine salt mix per litre, Mollies are actually very, very tough and will sail through the cycling process. They have been used this way in marine tanks for decades. It's in freshwater conditions, including "teaspoon salt per gallon" type situations, where Mollies die at the first sign of trouble. If all you have are Mollies for now, a box of the cheapest marine aquarium salt on sale will be just the thing. It'll handle pH, carbonate hardness and salinity all in one fell swoop, so is much better than freshwater aquarium tonic salt. Use as suggested above, and you shouldn't have any problems at all. Should you eventually decide to convert it to a freshwater system in a few months, that's fine, and you can do that. But for now I'd strongly suggest going brackish. Do read:
My neighbor's daughter has very little information about the fish, but she does know that her mother got them from a friend-of-a-friend as very, very young fry. That being said, I am almost positive that all of the fish are females. I was very suspicious that I was misreading their triangular anal fins, but the fins are identical to all of the photos of female mollies (and definitely not like the photos of male mollies) that I can find on the internet.
<You can't sex juveniles until they're about three months old; before then, the males will have triangular anal fins just like the females.>
If it is the case that all of them are female, would the mollies be okay without males in their tank?
<They will be very happy indeed.>
Or if everything else is successful in transferring them to the larger tank, would they be better off if I eventually added males to aim for close to a 4:1 ratio?
<No need to do this at all. In fact may be simpler. You need not worry about unwanted fry. In slightly brackish conditions you can also keep all sorts of interesting oddball fish as companions, such as Knight Gobies and Bumblebee Gobies, which thrive in the same conditions as Mollies.>
Thank you so much!
<Hope this helps. Cheers, Neale.>
Re: Mollies - 10/09/10
Thank you for the information! I did intend on setting up a brackish aquarium according to the suggestions on your site, and it's wonderful to know that the mollies can be in the tank for cycling; that way they can
have enough room much more quickly. I did think it was suspicious that all of them appeared to be female, so thank you for your help with that. Based upon my neighbor's daughter's estimation, the mollies are likely just around three months old, so time will tell for sure. I'm in the process of buying supplies and setting up my tank today, and your site has been an incredible resource!
Thanks again,
<Glad to help Amy. Mollies are perhaps the single best reason to set-up a low-end brackish system. There are lots of plants that will thrive in such conditions, as well as any number of tankmates. Knight Gobies and Glassfish are great for eating unwanted fry. Brown Hoplo catfish are fun scavengers, as are Horseface Loaches. Spiny Eels can work well, though they're fiddly fish to keep. Ticto Barbs, Rainbowfish and Wrestling Halfbeaks make fun schooling fish options. Port Acara, Blue Acara and Severums will all enjoy slightly brackish water. Some folks like Violet Gobies, despite their ugliness, get on exceedingly well with Mollies, and despite their size, don't eat the fry. Cheers, Neale.>

Lots of Molly questions, sys. hlth., reading 7/22/10
Hi everyone!
I've read so many articles from your wonderful website that my eyes are crossing! =) Reading through the FAQs has been incredibly helpful over the past couple months in helping me properly set up and maintain my 7 tanks (for the time being...this is a very addictive hobby to say the least).
<Good to know. Do make sure to read here:
Most problems with mollies come down to the wrong environmental conditions. Specifically, too small a tank, too soft water, too cool a temperature, and often, lack of marine salt mix to raise the pH, hardness and salinity.>
The tank I have a question about is my 10 gallon Molly tank.
<No such beast as a "10 gallon Molly tank". These fish need 20 gallons, minimum, for the Shortfin varieties, and 30 gallons upwards for Sailfin varieties.>
I started off with 2 female and 1 male (and 3 Mystery Snails to help with any uneaten food, not that the Mollies leave much behind).
<Apple/Mystery snails are not compatible with Mollies. Oddly, they do occur in the wild together. But the snails need cooler, less saline conditions so it's difficult to provide good conditions for both.>
The male is a silver Sailfin, one female is a black 'regular', and the other female is a Dalmatian Lyretail (who I was told was really pregnant when I got her, but now I think she may be some type of a balloon belly but I'm not positive). The male (White Lightning) showed absolutely no interest in the Dalmatian female (Starry) and was constantly chasing the black female (Stormy), showing off his Sailfin and swimming circles around her only allowing her a few minutes of peace at meal times and when she would lose him for a few minutes hiding amongst the plants and decorations.
<Inevitable in a tank this small. Stress will be the result.>
About 3 days ago I noticed Starry's behavior changing. She swims around some, she comes up for food or when I'm sitting in front of the tank talking to them, but mostly she stays near the bottom in the middle of the tank slightly above the gravel just wiggling back and forth (kind of hovering in one spot).
<Could be stress-induced, or water quality, or water chemistry.>
Occasionally she'll swim around the tank (looking for food I think), but usually she just stays in her 'spot'.
<Do learn to recognise "the Shimmies", a disease where Mollies seem to tread water. In serious cases they adopt odd swimming angles, rock from side to side, and eventually die. It's neurological, and caused by environmental stress.>
I've also noticed her kind of spasming a few times, not very often but maybe once a day for the past 3 days I've seen it. She'll be hovering near the bottom and all of a sudden she turns almost sideways to the left until her side brushes against the gravel and then she flips back upright immediately. It kind of reminds me of when a cat is about to flop on it's side to lay down. She still eats normally (always searching for food) and doesn't have anything odd on her body, no fungus or Ick-like spots, her fins are all in good condition, her eyes are clear, her poo is normal looking medium brown color like the others.
I did some research on your site, and decided I should get 2 more females to keep White Lightning company (and give poor Stormy a break), and that I needed to add salt to the water to hopefully help with Starry's shimmying issues.
<I'm surprised that in your research you missed the need for specific environmental conditions. If fish aren't unhealthy, adding more of them rarely improves things. Sure, adding extra Neons to a school of them will make them less nervous. But if the fish are visibly sick, then the first order of business is environment. Mollies can't be kept in 10 gallons, period.>
Off to PetSmart I went and purchased Moonbeam (silver 'regular' female) and Estrella (Dalmatian 'regular' female). I also purchased a box of API Aquarium Salt and a Tetra Whisper 2-10 gallon power filter to add to the Aqua Clear 10-30 gallon filter I already had to help with the extra fish.
<Again, you're missing the key things. Aquarium salt isn't what you need, marine salt mix is. There's a vast difference between them. Marine salt mix doesn't just add sodium chloride but also raises pH and provides the carbonate hardness that inhibits pH changes between water changes. It's like comparing water and wine -- they're both wet, but they're very different things. Adding extra filters is always a plus, but if the tank is too small, that's like sticking an extra engine onto a two-seat car -- it'll still only carry two people.>
Since it was tank cleaning day anyway I already had water sitting out to age overnight with the Tetra Aquasafe in it. I emptied out 3 gallons of water with the gravel cleaner thingie, rinsed off the filter media from the Aqua Clear in the old tank water and added the new water and the new filter. I added 2 tablespoons of the aquarium salt mixed with tank water to the aquarium (per the instructions on the box).
<The manufacturers of aquarium salt are being disingenuous, because they know that the only people who buy salt are inexperienced beginners. It's a shame, but there you are. For Mollies, you're aiming for a slight salinity, around SG 1.002-1.003, about 4-6 grammes per litre, or 0.6-0.8 oz per US gallon. Using spoons is pretty hopeless because salt packs down and it also absorbs moisture from the air, so the amount of salt per spoonful varies.>
Then I added Moonbeam and Estrella to the tank (they had been floated in the tank for 15 minutes and then placed in a 1 gallon Kritter Keeper with 1/2 their bag water and 1/2 tank water while the cleaning was going on). They both stayed near the bottom in a corner for about 10 minutes and then slowly started exploring. But Moonbeam seems to be acting like Starry, I usually find her hiding in a corner of the tank just wiggling (no flopping though and she does swim around more than Starry does).
Estrella likes to run interference for Stormy, trying to distract White Lightning when he's chasing Stormy around the tank.
<You're applying human hopes to animal behaviour. None of your Mollies are acting in the way you're describing. Individual females couldn't give a rip about other females, and don't do anything to "distract" males.>
But White Lightning still doesn't show much interest in anyone else, he'll 'sniff' around the other 3 briefly but as soon as he catches sight of Stormy he's off to chasing her again. He'll swim up underneath the others and check out their anal vent area but he never flings his Sailfin up like he does with Stormy and he doesn't chase any of the others or seem interested in them at all. I'm pretty sure Stormy is pregnant now, Starry may be, and I'm pretty positive Moonbeam and Estrella aren't (at least not yet).
<They are.>
Now for the questions (finally!): What could be wrong with Starry?
<Nothing. What's wrong is you put these Mollies in a tank far too small for them. The result is aggression and stress. Completely predictable.>
Should I quarantine her from the other fish or is this normal Molly behavior?
Is it normal for a male to only show interest in 1 female out of 4?
<Sure. He'll probably mate with them all, but his attention will be most focused on whichever ones exhibit what he sees as the best genes.>
Is the aquarium salt enough for the Mollies
<No, it's rubbish. Or rather, it's specifically for treating Whitespot and the like.>
or do I need to get something different to make the water brackish?
<Yes, marine aquarium salt mix.>
PetSmart told me the aquarium salt was fine
but I think I read on here that Marine Salt should be used.
<Correct; ask the clerk at PetSmart about how sodium chloride raises pH and carbonate hardness. Then ask him what carbonate hardness is for. If he can't answer those correctly he should stick to selling canned dog food.>
Or do I need to add more aquarium salt? (I've read anywhere from 1 tablespoon per gallon to 1 tablespoon per 5 gallons.)
<Not by spoons, by weight, though conveniently 6 grammes of marine salt mix should be about 1 level teaspoon, so about one-half to three-quarters of a level teaspoon per litre should be just about right. Since Mollies don't need a specific salinity, any slight variation won't do any harm so long as you don't add so much the filter bacteria and/or plants get stressed. Mollies themselves are happy in fully marine conditions, so salinity isn't an issue for them.>
Is the aquarium salt dangerous to the Mystery Snails?
<Yes, it kills them.>
They seem to be acting normal since I added it, but I don't want to hurt them either. Is it ok to keep 5 Mollies and 3 Mystery Snails in a 10 gallon tank or do they need more space?
<You need a 30 gallon tank, minimum. Don't have that kind of space? Don't keep Mollies. There are lots of alternatives:
All of the Mollies are 1 1/2 - 2 inches in length and the Mystery Snails are about 1/2 inch in diameter or slightly smaller.
<Irrelevant to the aquarium size..>
Ok, now for tank info.... 10 gallon all glass aquarium with hood and light Aqua Clear 30 power filter for 10-30 gallons Tetra Whisper power filter for 2-10 gallons Heater (75 watt I think, it came with the tank set up) Air pump and 6 inch bubble stone 4 live plants (2 ribbon plants, a small dark green fern, & a water lily drop in the tank bulb that has leaves up to the surface now) Several fake plants 3 hideaway decorations Temperature stays between 80 and 82 Nitrate: 20 Nitrite: 0 Hardness: 150 Chlorine: 0 Alkalinity: 120 pH: 7.8
<Water quality sounds fine. Shame the tank is too small.>
All I have is one of the 6-in-1 dipstick type test strips, there isn't an ammonia test on it. After reading through your site I know I need one of the vial type test kits but PetSmart was out of stock the last time I went in. Do these usually include an Ammonia test or is that one separate?
<You don't need an ammonia test kit. A nitrite test kit is fine. If nitrite is 0, ammonia is probably 0 too.>
Also, water changes are twice a week (2-3 gallons each time) and the gravel vacuumed once every 2 weeks because it usually takes me too long to get the 'self-start' function working and I don't want to stress the fish out too much swooshing it around in the tank. Fish are fed small amounts 2-3 times a day with either TetraMin Tropical Crisps, Tetra Freeze Dried Blood Worms (3 times a week), or a strip of Top Fin Natural Dried Seaweed (3 times a week).
Sorry this was so long, I just wanted to explain everything the best I could. Any help or advice you could give will be greatly appreciated! Thank you! Amy
<Done my best! Cheers, Neale.>

Mollies... the usual iatrogenic sources of trouble -- 07/16/10
Good morning,
<Hello Carly,>
We have 2 tanks. One is a 60L and the other is a 95L,
<Both tanks are much too small for Mollies. You honestly can't expect them to succeed in tanks this small, no matter what. Without upgrading the tanks, anything else I say will be pretty pointless. 115 litres (30 US gallons) is about the minimum for Mollies. Females may be kept on their own in slightly smaller tanks, including the 95 litre tank you have, but males will be absolute terrors. The 60 litre tank is of no value at all for keeping Mollies.>
The problem that we are having is that we have 4 balloon Mollie girls (Various colours) and 1 male. First of all the male is terrorising one of the females, he constantly mates with all but this one. And since he cant mate with her he chases her around and its starting to stress her out.
<Well, I'm sure ALL the females are pretty stressed. But yes, this is "normal" unfortunately, and what male Mollies do. Di you have floating plants in here? Indian fern for example? If the answer is no, then get some.>
She is smaller then the other females, but that all that different, she just doesn't want to mate with him! I've noticed over the last two days that she looks as if she is starting labour, then everything closes up again, is this from the stress of the male?
Should we remove the male?
<I would.>
The other thing is, the male he is definitely a Dalmatian Mollie, but not a balloon like the shop said, he is very small, and slender and zips around like a dart.
<Balloon Mollies are obviously deformed. When people bred them they chose deformed fry, bred them together, and over the generations produced more and more deformed Mollies. It's pretty sad really. One problem is, as
you've noticed, female Balloon Mollies can't swim fast, and that means they can't get away from the males. Healthy Mollies are streamlined, fast-moving fish, which is part of the reason why they need quite large and spacious tanks.>
Any idea what breed of Mollie he could be, or is he just a junior?
<The deformity that characterises Balloon Mollies is obvious almost from birth, so I'm guessing you have a healthy, normal, and I'd argue luck Dalmatian Molly that hasn't got the genetic flaws that deform the spine and give rise to the Balloon Molly.>
Last question: We had a red wag tail platy gave birth to 150 fry in one sitting, then died a few days later. Then we had a case of whitespot, and only have 30-40 babies left. They live in a breeder trap but still more die, we have treated the whitespot, but the fish still flash in the main tank, what are we doing wrong?
<Difficult to say without some data. Platies need hard, basic, cool water; you're aiming for 10+ degrees dH, pH 7.5-8.5, and a temperature between 22-25 C/72-77 F. If kept in soft water, acidic water, or overheated water,
they won't do well.>
4 Female balloon mollies, 1 male
4 female guppies, 1 male
5 neon tetra,
4 green neon tetra
<Neons and Green Neons are not only incompatible with one another, but they're totally incompatible with Mollies. Neons need soft, acidic water at a cool temperature; 3-10 degrees dH, pH 6-7, 22-25 C. Green Neons also need
soft, acidic water, but must be kept water, 25-28 C/72-82 F. Trying to keep both together almost certainly means one or other is stressed.>
1 Bristlenose Pleco
<Need the same things as Neons.>
3 Female Platies
1 male
2 2month old juniors
2 Female fighters
1 male
<Mollies need warmer water than Platies, and harder water than either Neons or Green Neons. Please, for the sake of your fish, read about the needs of your fish BEFORE you buy them.>
60L Tank
8 Rummy nose tetras
1 Male fighter
2 frogs
1 albino red tailed shark
1 apple sail
1 albino bristle nose Pleco
<I feel sorry for the Red-tail Shark and the Rummynose Tetras; both these species have no business in a tank this small; even one three times the size would be cramped for them.>
Both tanks are cycled, and read at:
PH: 7.0
<Much too low for Mollies and Platies; no wonder the fry are dropping like flies. The stress on your Mollies could be down to this. Do please understand hardness, carbonate hardness, pH, and their importance to livebearers.
Water changes done weekly or more frequently if needed.
Thank you for reading my rambling.
<Happy to help. Good luck, Neale.>
Re: mollies 716/10

Good Evening,
Thank you for your reply, will take care full notice of what you have said, I have a 450L put back which I am paying off and hope to have with me asap.
The fish will be re-arranged as to there needs. Once again thank you for your knowledge and website.
<Glad to have helped. Good luck, Neale.>

GROSS MISINFORMATION!!! Rant re Mollies and guppies brackish water fish? 3/20/10
I don't know who you idiots are, or where you got your information but you are either terminally ignorant or just aggressively stupid!
<Hmm... seems a bit of an aggressive way to start an e-mail!>
Mollies and guppies brackish water fish?
<They can be, yes. Mollies are certainly common enough in slightly brackish water habitats, and in places may be found in fully marine environments, as in the Gulf of Thailand. Curiously, Mollies are more common in freshwater
habitats than brackish, but under aquarium conditions, where they are exposed to varying pH and high levels of nitrate, slightly brackish water conditions do seem to work consistently better. No-one is arguing that either Mollies or Guppies are exclusively brackish water fish -- let's be clear about that! -- but under aquarium conditions the addition of a little marine salt mix can make the difference between success and failure. In a nutshell, sodium chloride detoxifies nitrite and nitrate, while calcium carbonate raises pH and steadies it. So in situations where they aren't being kept in hard, nitrate-free water, the use of marine salt mix provides key benefits.>
That is just plain stupid!
<It's really not. I don't know how old you are, I'm guessing you're in your late teens, early 20s, but honestly, the use of marine salt mix when maintaining Poecilia spp. is well known and has been established practice for a good 100 years or so.>
I used both mollies and guppies in my mosquito control research at Texas A&M and they all lived in freshwater.
<Wild caught fish or aquarium fish? Inbred fancy varieties or crossbred/feral types? Both these factors makes a difference. There's ample lab work to demonstrate that wild-caught Poecilia reticulata are much hardier and more adaptable than the inbred fancy forms sold in pet stores.>
They were all very healthy and reproduced successfully.
<Good for you.>
Your attempt at "educating" the public resonates like nails on a chalkboard!
<In what way?>
Your misinformation does a lot more damage than good.
<On the contrary. If someone is keeping their Mollies in freshwater and finding they're constantly having trouble with Fungus and Finrot, the addition of salt will help significantly.>
Imagine some poor soul losing all his fish because YOU told him they need to be in brackish or salt water!
<Not going to happen. There are many reasons Mollies die, but being maintained in brackish water isn't one of them. Go spend a little time reading about the natural ecology of Poecilia sphenops and its relatives.>
Definitely some liability there for sure.
<None at all.>
Go buy a guppy and put him in brackish water, it will be dead in 24 hours or less!
<An insane comment. Poecilia reticulata will live a long and happy life at 10% seawater salinity, around SG 1.003. Compared to its survivorship in soft, acidic water, the same guppy moved to slightly brackish water will live much longer and be more healthy. Basically, you're talking nonsense.>
The fact that they can withstand high salinity levels for a short period of time does not mean that is their ideal environment! I'm sure you would last in the desert for a little while too!
<The two issues are unrelated. Guppies and Mollies are freshwater and brackish water fish in the wild. End of story.>
I'm sure you will not post this message on your site since it only highlights your ignorance/incompetence.
<Better believe we'll post it.>
I will consult with some colleagues on Monday they will likely be as appalled as I am.
<If by "colleagues" you mean other uninformed undergraduates, by all means, go ahead. For what it's worth I have a BSc in marine zoology and PhD in cephalopod palaeontology, I'm an assistant professor at Pepperdine University when I'm not writing books and magazines, I have a fish named after me, and oh yes, I'm the editor of the TFH book on brackish water fishes entitled (imaginatively, I know) Brackish Water Fishes. If you have a grown-up nearby who'd like to debate, I'm game!>
Who knows maybe we can get your site shut down as we have done with other less than reliable sites in the past.
<Sit down, take a deep breath, and maybe put the kettle on and have a nice cup of tea. You're wildly overreacting and speaking from a position that makes not much sense at all. You are quite correct in saying that Poecilia spp. can live in freshwater habitats, and indeed do so in the wild more often than they inhabit brackish water habitats. But life in aquaria places unique stresses on fish, which is why only a few hundred fish species out of the 30,000 species known have become regular aquarium residents. Among other things, nitrate toxicity and exposure to varying pH can cause problems, and the use of marine salt mix is good at offsetting these issues. This is why Poecilia spp. can be, and often are, maintained in slightly brackish conditions. Whether they MUST be maintained in such conditions has been endlessly discussed, and is a favourite topic of argument among expert fishkeepers. But is it EASIER to keep these fish in slightly brackish conditions? Often, it seems so.>
<I'm sorry you feel this way.>
Good Day!
<So far, yes, it's been a lovely day. Cheers, Neale.> <<Unsigned? More FFA (Future fascists of America) monotribe monomania idiocy. RMF>>

Re GROSS MISINFORMATION!!! Rant re Mollies and guppies brackish water fish? 3/20/10 3/21/10
Hi Neale,
Geez, I don't know how you were able to control yourself answering that person, but the way you handled it exemplifies your integrity as to not ranting off like a bloomin' idiot as he had.
He sure has a lot of balls questioning your knowledge/advice. If it were me, having the knowledge and degrees as you, I'd likely have told him that if he believed my advice is inaccurate, go elsewhere.
You certainly handled that tactfully. Hat's off to you.

Good Job! 3/22/10
To all my friends (at least I think of you that way!), and especially Neale, at WWM.
<Hello Bill,>
No question this time, just a word of praise.
<How lovely!>
Thank you very much for all the work you do for all of us out here in the wonderful world of fishkeeping. I was prompted to write this to commend Neale on his reply about the guppies and mollies in fresh or brackish water. He remained polite and on topic - it was a pleasure to read his reply, even though I have not kept a fresh (or brackish) creature in at least 30 years.
<Well, thank you so much for saying this.>
Was it an early April Fool's letter?
<Hadn't thought of that! Possibly a little early for that, though...>
Please keep up the GREAT WORK!!!!
<We will certainly try.>
<Cheers, Neale.>

Black mollies, hlth., env.... the usual 3/1/10
I have 3 adult black mollies and 3 young mollies- about 8 weeks old. The tank was set up in December and we received the adults before it cycled (I've learned a lot about having fish since then)
<Good. Now, I have to be frank here, Mollies are appalling fish for new aquaria. They are very intolerant of nitrite and ammonia. They are poor choices for average freshwater aquaria having very specific needs. Mollies need hard, basic water with zero nitrate content. The water chemistry has to be "liquid rock", pH 7.5-8, 15+ degrees dH, 10+ degrees KH.
I notice with some alarm that you're not providing anything like these conditions, and that's why your fish are sick. Mollies are much hardier in brackish water, but that requires the use of marine salt mix at much higher levels than most freshwater fish will tolerate, so this isn't viable for mixed community tanks (though you can of course have a brackish water community of Mollies with gobies, sleepers, glassfish, guppies and other small to medium sized brackish water fish).>
The fry had large bellies and the adults had white spots (not ich)-- I checked and the nitrites and nitrates were off the charts.
<Not good. In freshwater conditions ammonia and nitrite MUST be zero, and nitrate as low as possible, ideally zero, and certainly less than 20 mg/l.>
I did an extreme water change I read about online and the fish all seemed to get better. The young mollies still have white bellies- and I want to make sure that is normal.
<Colour varies a good deal, especially with crossbreed Mollies.>
The adult female seemed to release some kind of egg sack recently-- her gills seem to be getting more silver- is that normal?
<Not really, no. But I wonder if you mean the gill covers are silver, and this may be natural colouration, or may be excessive mucous production. The latter will appear grey or off-white rather than metallic silver.>
My biggest concern is with one of the adult males (KD). Last week his back fin seemed paralyzed. I treated the tank for 5 days with Maracyn with the coal filter removed to treat the white spots I was seeing. I also bought a new heater to control the temperature fluctuations. KD started using his tail more the last few days, but today we introduced a Plecostomus and KD's scales on the back half of his body are white and seem to be sticking out; also looks like there some kind of tissue coming out of the gills -- swear he was ok this morning. His back fin looks like a feather when its been played with too much and the barbs get stuck together. I have separated him, but have no idea what he has or how to treat it. In writing this, he's flipped on his side, dont know if he'll make it.
<He is severely stressed. In the right conditions he'll pep right up, but unless you fix things, this isn't going to happen.>
Tank size: 20 gal
PH: 7.6
<Far too low. That's about 2 degrees KH, whereas you're actually after about 10 degrees KH.>
hardness: above 300
nitrite: between .5-1.0
Included pick 2 picks of young mollies & 2 of sick fish
<Do please send smaller images. We have limited e-mail space, and you sent 15 MB of material, and once that allowance is filled, other folks have their messages bounced back. We do specifically ask for pictures no bigger than 500 KB, right where you found our e-mail, and we're asking not to bloody minded, but so that everyone has a chance to send their messages to us every day.>
<Much reading and work to do. If you're only keeping Mollies in this tank, then switching to brackish water, around SG 1.003 at 28 degrees C/82 degrees F (about 7 grammes of marine salt mix per litre) will help significantly. Otherwise, harden the water using the Rift Valley salt mix at about 50-100% the dose recommended depending on the other tankmates (other livebearers are fine with very hard water, but tetras and other fish won't be). Water quality needs to improve dramatically. Cheers, Neale.>

molly tank size 2/15/10
Dear Crew,
Thank you for an informative and interesting site. I would value your advice. I recently bought a 48l tropical tank,
<Or 12 US gallons -- too small for Mollies. In fact stocking a tank this small is very difficult. Read here, and treat this tank as a 10 gallon tank in terms of species selection:
and my LFS suggested starting with 4 mollies.
<The sales clerk here wasn't being helpful at all! Can't think of a WORSE fish for starting a new tank than Mollies.>
I bought 4, 3 females and 1 male. I then rather belatedly did a lot of reading and this would seem to suggest that my tank size is about half of what it should be. Two LFS however have both suggested that it is fine, and that I could even add more fish.
<I'm not selling you anything. He is. Who you going to trust?>
So my question is, how long will my Mollies be happy in their current accommodation,
<Couple of months perhaps. Likely half will die from one thing or another, and some will be okay. Often the way with Mollies kept in freshwater. May even get some babies, and you'll mistakenly assume that means they're
happy. It doesn't. The babies were conceived weeks, even months, ago.>
and would I be better off keeping them as a species tank (even if I did upgrade - again have heard contradicting advice).
<Mollies are best kept in their own system, with appropriate water chemistry. Since this usually means adding a bit of salt, that rules out most freshwater fish, so they're best on their own.>
Thank you very much,
<Do read here:
Cheers, Neale.>

Re: molly tank size 2/16/10
Dear Neale,
Thanks for your help.
<Always happy to help. Cheers, Neale.>

Re: molly tank size 3/7/10
Dear Neale,
Following your previous advice, I am going to upgrade my tank! Before I make another expensive mistake, I would value your advice on my plan.
Thinking of 200l tank, with brackish water (approx 5g per litre marine salt as you recommend) and gravel substrate. Will my current elodea plants be okay with this - was also going to add java fern and moss.
<All three of these plants will thrive in such conditions. Actually, start off with just 3 g/l salinity for now, and see how things go. At 28 degrees C that should give you a specific gravity of 1.001-1.002. That should be ample for Mollies, and will give the plants some time to adapt, and the filter bacteria too. Only after a few months think about changing the salinity upwards.>
Would like to add other fish, maybe guppies and Platies, but don't won't the population expanding exponentially so thought of adding glassfish.
<Glassfish will gobble up any Molly and Guppy fry they see! Unbelievably fast predators when they want to be.>
Also would a bumblebee goby be a good mix?
<Not a bad choice at all. Or Knight Gobies. In either case, your main issue is feeding, since BBGs are a bit slow on the uptake, and will need wet-frozen foods directed right at them. In a planted tank you might have problems seeing them at all. So buy a couple, see how you get on with them, and if they're still nicely plump after a month, you might add some more.
Knight Gobies are more outgoing (and also VERY predatory) so they're generally easier to feed. Look out also for Neovespicula depressifrons, a grouper-like fish sold as the "Butterfly Goby". It's a type of Waspfish, and though predatory, isn't big, about 10 cm/4 inches, and is peaceful enough to keep with Mollies too big to swallow. Awaous flavus, the Candy-stripe Goby, is another option. One of the neat things about Mollies is that they're a good starting point for a low-end brackish community, and once you see that as an opportunity to keep fish you couldn't otherwise keep, the whole "does better in slightly salt water" stops being a headache.>
Can I add my existing fish straight away if I put my old filter, with some of the gravel, in the new tank (along with the new filter)? How soon could I add new fish (would need to use the 48l tank as an incubation tank, so would need to put the old filter back!)?
<Your existing filter will adapt to the slightly salty water, so yes, you can combine both filter, or move media from one into the other, as you need to. I'd get the Mollies settled, leave the new filter for a week or so to settle down, and if you still have zero ammonia and nitrite levels, add a few new fish that weekend. Leave 2-3 weeks between adding each new batch of fish.>
<Hope this helps. Cheers, Neale.>
Re: molly tank size 3/7/10

Dear Neale,
Thanks very much for that excellent advice. Is it a good idea to have the predatory on fry fish?
<Depends. Mollies will produce fry every month, and even if only a couple survive the critical first week or so, you'll end up with a dozen more adults by the end of the year. Some folks don't mind, and happily confine
fry they find in a breeding trap, so more survive, and every few months decamp some of the subadult fish at their local pet store. Other people don't want any of this, and prefer at least one fish to keep population numbers strictly limited. In most community tanks, things like Angels do this very well.>
Do a few survive or are they all just dinner?!
<If there are predators in the tank, like Knight Gobies or one of the freshwater archerfish (Toxotes microlepis, a great addition to a low-salinity Molly tank) then almost all of the fry will be eaten. You can use a breeding trap to isolate any you want to rear, and depending on the size of the predator, then within a month or two these will be big enough to turn loose in the tank.>
<Cheers, Neale.>

Re: molly tank size 3/8/2010
Thank you!
<You're welcome. Cheers, Neale.>

Molly & Dollar... beh., sys. 1/18/10
I have quite a strange situation going on and I'm honestly not too sure how to go about fixing it.
<Do start by reading here:
Mollies are very misunderstood, and a depressing proportion of them end up dead prematurely.>
Recently, my boyfriend and I purchased a balloon molly as well as a silver dollar. Just the other day we also purchased a 29 gallon tank, so in a week or so we will be getting a few more of each.. the thing is, our molly seems to adore the dollar. Whether or not it's a sign of aggression, I'm honestly not sure.
<It is aggression. I've seen this same thing before with Sailfin Mollies and Australian Rainbowfish.>
Basically what is happening is that our molly is always stuck right next to our dollar. Usually that's all he does, he just sits next to the dollar, occasionally he may kind of rub up against the dollars side.. sometimes though the molly sort of nips at the dollar's side and the dollar may take off suddenly but usually slows down and the molly's right next to his side again.. now the dollar doesn't seem to mind the molly all that much- usually if the molly goes off to pick at some food or whatever, the dollar is right behind him... I've read before that sometimes mollies will nip at
other fish but not in a harmful manner. I'm not sure if this is true but I'm just beginning to wonder how much stress this is causing the dollar, if any at all... I have searched the web and cannot find this same situation happening to anybody else. As I said, in a week or so we will be moving them to a bigger aquarium, I'm just wondering what might happen if we get a few of each.. we were thinking of at least one other dollar, maybe two, but reading this site, it looks as if I'll need more...? Please tell me what you can! As I said, the molly really doesn't seem to cause any harm at all to the dollar- he seems to absolutely adore him.. and to be honest- the dollar doesn't really seem to mind the molly all that much either.. I attached two photos, both of them have each fish together.. the second one is a little tougher to find the dollar but if you look at where the molly's lips are....... I apologize for the lack of quality, I lost my camera so I had to use my phone to take the pictures.. Anyway, please let me know if this is causing stress on either fish or if it will once we purchase a few more! Thanks so much .
<Now, there are two issues here. Firstly, Silver Dollars are schooling fish. They need to be in groups of 5 or more specimens. They also get very big. VERY BIG. So unless you have a 55 gallon tank in the near future, don't keep them. These are big, nervous, herbivorous (eats plants) fish not suited to the average community tank. Now, as for the Molly. Male Mollies fight for dominance by showing off. Essentially they display their size and fins to one another, and the one with the biggest fins wins. What happens if a male Molly is in "solitary" confinement is that he looks for females (finds none) and looks for rival males (finds none). Then he looks for anything that *might* be a Molly. My guess here is that arch-backed fish -- like Australian Rainbows and Silver Dollars -- resemble the silhouette of a male Molly with erect fins. In other words, your Molly thinks the Silver Dollar is another male Molly threatening him. There's no resolution here -- the Silver Dollar can't change his shape -- the male Molly neither beats the Silver Dollar nor gets the Silver Dollar to back down. So the rivalry goes on and on. The two species are not really compatible, so I don't see any point trying to get them to live together. Mollies need very warm, very
hard, basic water, ideally slightly brackish; Silver Dollars want middling temperature, soft, acidic water. Put each in their own aquarium suited to their needs, and your problem goes away. Simple as that. Cheers, Neale.>

Re: Molly & Dollar... sys., comp. 1/27/10
Hey guys, I have to thank you for responding so quickly, I didn't expect it which is why I'm a little late!!
Sorry. But basically, I had been speaking with Neale last time, not sure how this works or if I'll get him again but I have a balloon molly and Neale helped me out a bit with the facts of mollies and silver dollars..
<I'm here again.>
Now I mentioned I had a 29 gallon tank that I would move them to soon enough and I realize it's not very big atm but it's what I can afford right now so it's what I have to deal with .
<Well, while I sympathise, science is notoriously flexible. If a fish needs bigger space, it needs bigger space. Inconvenient but true.>
I realize a little too late I should not have bought these fish as impulses because I liked the way they looked, but rather should have read up on them- as a result of that, I now have separated a Betta to his original like 5 gallon tank (he doesn't seem to like the silver dollar anymore now that they're in the 29 gallon tank, but when he was in the smaller tank he honestly didn't chase him once) and a paradise fish to a 10 gallon because I did not know that they were in the same family and would constantly battle.
<Indeed. Macropodus opercularis is a difficult fish, and consequently not widely kept.>
Not to mention the paradise fish is what I would call a prick to the other fish- constantly picking on them, and even killing one of our barbs
<It's their nature. Males are aggressive because they're excellent parents.
They guard their nests. It's like complaining about cats catching birds... it's what they evolved to do.>
:( I asked the guys at the pet store if the paradise fish were aggressive and if he would get along with the Betta- the guy told me "No, they're very timid fish and should get along great with the Betta" .
<As we often point out here, if you'd read about the fish before purchase, the fact your retailer is an idiot wouldn't be an issue. But then again, would you rely on a guy in a car showroom to sell you the perfect car without reading up on that make and model first? No.>
So I learned the hard way they are actually quite mean fish- beautiful and interactive but don't get along well with others.
<This isn't a surprise. Any book would tell you these subtropical (not tropical) fish are interesting fish for single-species planted tanks.>
I also have 3 (used to be 4) cherry barbs which I adore, two (used to be 3) random little tetra that seem for the most part to enjoy the tank, an algae eater, and 2 yoyo loaches.. I know the tank is soon going to be very crowded after doing some reading up on how large all these fish will get but as I said, at this moment, all I can deal with is having them in the 29 gallon... Anyway, so back to the point- since I've moved the fish into the 29 gallon, none of them are eating properly.. my balloon molly tries to eat all the time but he's constantly spitting it back out- right at this moment he's at the surface at the water, looking like he's trying to suck back air-
<What Mollies do when conditions aren't quite right. Mollies are able to shunt water from the very surface across the gills, and thereby extract oxygen even in stagnant pools. A handy trick in the shallow canals and pools they inhabit in the wild. However, if they're doing this regularly, it's a good sign there's something amiss. Check, at minimum, the nitrite and pH. You're after 0 nitrite and a pH around 7.5 to 8.>
I had seen a few other fish do this so I opened the lid a little, hoping maybe this would help get the humidity out and some oxygen in....
<Why would fish care about humidity? They live under water!>
he will still swim around normally the majority of the time but he no longer eats right and as I said, is seen trying to suck the air back. Now none of the other fish will eat either which I don't understand- they all try but each one of them spits it out which makes me think there's something in the water, even though we use the same water we used in the old tank and they seemed to eat fine then..
<Same water? Meaning what? Let's be clear here, filter bacteria aren't in the water. So moving water from one tank to another doesn't magically cycle a new aquarium.>
I read that sometimes it's just due to the fact that they no longer enjoy the food, so maybe I should try a little switch?
<If all the fish are off their food, this is unlikely the issue here. Check water quality and chemistry instead.>
I heard most fish actually enjoy fruits and veggies, is there any certain kind that they cannot eat or..? I am blaming this on the water though, my Betta and paradise fish both eat perfectly fine and the paradise fish eats the same food as the little guys..
<Both these fish are air-breathers, and much less sensitive to poor water conditions, e.g., overstocking, under-filtering, than most other fish.>
also, my yoyo loach used to LOVE his pellet food- the bottom ones that look like little pills? The other fish generally used to pick at it as well- especially the molly and the barbs. Now no one eats it, it sits at the bottom and just breaks apart, making a huge mess everyday. I'm afraid I am going to lose all my fish, I really don't want to. I need to know some way to make it a bit better for them, at least to get them back to eating normally again.. I have live plants in there from the pet store and the plants seem to be doing perfectly okay.. is there not enough salt for the molly or too much acidity or something?
<You haven't given me any information here, so can't possibly say. I will tell you Mollies need hard, basic water that's quite warm and very clean; i.e., 15+ degrees dH, 5+ degrees KH, pH 7.5-8, about 28-30 degrees C, and 0 ammonia and 0 nitrite. The addition of 3-9 grammes of marine salt mix per litre is extremely helpful, even if not 100% essential. Obviously not all fish accept brackish water, so you have to be careful here.>
Should I go buy a kit today to try to find out what's wrong? And again, I realize the molly is in the wrong environment per say, but he did fine in the other tank with all the same fish, same water, same plants, same decors.... so what is so wrong about this tank??? I realize I keep writing out novels for you guys but I'm just trying to provide you with as much info as I can to get some feedback!! Thanks guys!
<Keep reading. Cheers, Neale.>

Aggressive or mating mollies? -- 11/23/09
Hello, I recently added a male and female Dalmatian mollies to my 10g tank.
The e tank already housed 1 dwarf Gourami, 2 male fancy guppies and an African dwarf frog. The male molly seems to pick on the female every once in a while. Sometimes they'll be swimming together just fine and dandy and then a couple min. later it looks like he starts to nibble at her side.
Are they mating or is he picking on her? I have searched and searched for the answer and have found NOTHING! Please help!
Thanks! Kendra
<Hello Kendra, you couldn't have searched very far! Honestly, Mollies can't be kept in a 10 gallon tank precisely because the males are so aggressive.
You also need to keep at least two females per male, otherwise the male will pester her. This is so stressful for the female that miscarriages become a very serious possibility. Do read here:
A 20 gallon tank with hard water and preferably a little marine salt mix added (3 grammes per litre should be fine) is what you want. Stock with some floating plants such as Indian Fern to give the female some cover; baby fish will also hide in the plants long enough for you to find them and remove them to a floating breeding trap. Guppies tolerate salty water well, but Frogs will not, are aren't compatible with Mollies. None of these is news, and if you'd looked in any aquarium book, you would have come across information along these lines. Cheers, Neale.>

My lovely mollies... sys., beh./comp. 8/5/09
I have a 50 gallon aquarium that holds 2 male silver dollars, 8 zebra Danios (2 of which are Glo-fish), 3 cherry barbs, 2 glass cats, and 6 mollies - one silver male, one Lyretail silver female, one black male, one
black female, one Lyretail Dalmatian female, and one creamsicle female.
<Mollies don't usually do well in freshwater tanks, and if you must keep them in freshwater conditions, you need three things: a high pH around 7.5 to 8; a high hardness upwards of 15 degrees dH; and very clean water, 0 ammonia, 0 nitrite, and less than 20 mg/l nitrate.
Virtually all Molly problems come down to people insisting on keeping their Mollies in freshwater tanks -- despite what all the books say about them often needing slightly brackish water to do well. I cannot stress this point too strongly because I get Molly questions several times a week, and they often come down to this "mistake".>
Here's the problem, the silver male is very large compared to everyone else (about 4 inches) and is causing havoc.
<Normal. Keep adding females of his species (Poecilia sphenops, Poecilia mexicana, or whatever.) until he cannot bully just the one female. Adding floating plants helps a great deal too.>
He is chasing everyone - all the females and the male, and has even nipped up the tales of all the Lyretail girls. Now, the silver female seems to be losing her color and turning slightly gray. Can I assume this is due to the stress the silver male is causing?
<In part, yes, stress weakens the immune system allowing opportunistic infections to develop. On Mollies, these usually manifest themselves as Finrot, Fungus and/or Columnaris. These three diseases are very common when Mollies are kept in freshwater tanks, and even if your Mollies were healthy enough for a while, any negative pressure on them, such as bullying, could tip the balance in favour of these diseases. So, to recap, keep more than two females per male, and keep them in brackish water so these diseases are
less likely. It's really very simple, and explained repeatedly here and in aquarium books.>
He was acting fine when we first got him, but then the silver female that was in there with him died, and he starting chasing everyone. We went and bought the new females to try to calm him down, but it doesn't seem to have worked. He especially picks on the Dalmatian - I couldn't find her for 2 days, then she showed back up with her beautiful tail looking all torn up.
Now, if she gets near him, he immediately chases her away. He doesn't bother any of the other fish in the aquarium. Is there something I can do to calm him down?
<No. Male Mollies are aggressive. Evolution has worked to cause male livebearers to be aggressive and promiscuous because they are smaller than the males and have brighter colours, so are more vulnerable to predators.
So where a female can be picky because she'll live a year or two beyond maturity, a male only has a few months, if that, after sexually maturity, so he has to drive away rival males and inseminate as many females as he possibly can. You might not like the way evolution works, but there's nothing you can do about, and in the case of Mollies, this is the reality.
You could try adding two more males of his species, together with at least four more females of his species. The males might end up directing their energies towards each other some of the time, and if you had three of them, the one dominant male couldn't bully either of the other males exclusively.
Adding one male would be a nightmare, and the dominant male would likely batter the new one.>
I feel sorry for all the others - can you please make a suggestion as to what I can do? By the way, the water parameters seem to be fine and no other fish are showing any signs of health issues (with the exception of
the graying female and the now pitiful tails of the female Lyretails).
<The graying female likely has a bacterial infection, and you will probably need to treat.>
I greatly appreciate any advice you can offer, you are the best!
<Cheers, Neale.>

Mollies, freshwater plants and fixing my mistakes 6/30/09
First, hello and thank you for such a wonderful site. I truly wish I had found this site long before I did.
<Thanks for the kind words.>
I especially wish I had found it before I went to the LFS and bought several "mistakes" that I now need to correct! (I am no longer certain that my LFS should be allowed to sell hairpins, much less living creatures
they know little to nothing about...)
My young daughter asked for a fish tank for her birthday (she is three - and I *do* know that I will be doing all of the work!). Knowing that bigger is usually better and easier, I arm wrestled my dear husband into a 30 gallon tank. I have a 3 stage power filter running at 200 gph, heater (77 degrees or so), Cora-life light at 92w (about 3pwg) and Fluorite substrate. I ran the tank mechanically for a week, then added live plants (an assortment of South American easy-care plants: Egeria, Cabomba, Bacopa, tenellus, Ludwigia and Vallisneria).
<Some of those will definitely be easier to keep than others... but you'll soon spot the species that struggle!>
I let this run for a further two weeks.
<Sounds good.>
Here in south central PA we have very hard water (24GH) with a Ph around 7.6 or so. The KH is usually about 5 out of the tap. Thus, after carefully researching (or so I thought) I selected mollies for my daughter.
We hoped for easy care yet interesting fish with the possibility of some fry...
<Ideal water for Livebearers!>
We brought home one male and three female chocolate Sailfins as well as six pygmy Corys and two Oto-cats for algae. We carefully watched the ammonia rise to 20ppm then fall as the tank cycled. I never saw a significant nitrate or nitrite change. We *do* have a trivial amount of nitrite in our natural water - just enough for the dip test to register but no more.
Water changes at the moment (new tank) are on the order of 10% every two to three days. I was hoping this would fall back to a weekly chore once the tank was established.
<It will; especially once the plants get established, you should find the combination of plant growth and decent filtration rate should take care of ammonia and nitrite.>
Six days after bringing them home... you can guess. My carefully selected, slim, not-pregnant female mollies had fry. I had planned to allow nature to take care of this first batch but my daughter fell in love... now I have a hastily set up old 20gal tank with the fry and the original 30 gal as well. (hubby is not exactly pleased, he voted for a goldfish bowl...)
We have lost all but two of the Corys but all water parameters seem fine. Surprisingly, the fry are doing well in their uncycled, undecorated tank (at least so far). I did move some of the water from the 30 gal into the
20 to help start the cycle and robbed the filter floss from the older tank for the newer one...
I came to your site and learned that the aquarium salt my LFS sold me is not the correct thing for the mollies. Worse, the Corys they assured me were fully compatible actually do not tolerate salt! (I have not yet determined what the Otos think about the tablespoon of aquarium salt per 5 gallons I added... probably not happy about it either!)
<They don't like salt, and they don't like warmth, so I wouldn't ever keep them with Mollies; Mollies certainly need warmth, and do prefer slightly saline conditions.>
So my questions are these:
1. My mollies need marine salt - I have purchased it. Can I give them enough salt to make them happy without killing my plants? If so, how much?
<Start with about half a level teaspoon (3 grammes) per litre of water in the bucket; that should produce a specific gravity of 1.001 at the 27 degrees C that Mollies prefer. See how things go. Your water is very hard, so salt is much less critical than otherwise.>
2. The tank already has aquarium salt in it. Do I just start adding the marine salt for water changes? Do I make a large water change and switch over? The tank is really only about 5 weeks old - not fully cycled yet.
<Just add the salt to each new bucket of water added during water changes.
Don't worry about changing the salinity all at once.>
3. Will the Corys and Otos do well? Do I need to get rid of them? Will I need another algae eater in their place?
<Hardy Corydoras will tolerate very low levels of salt as suggested above just fine; Otocinclus are more of a problem. Neither catfish appreciate warm water: both are best at around 23-24 C. Mollies are darn good
algae-eaters themselves, but alternatively I'd go with Florida Flagfish and Nerite snails, both of which will thrive in slightly saline conditions.
Amano Shrimps will also do well, as should Cherry Shrimps.>
4. Do the fry need the same salinity as well? (By the way, your FAQs on raising fry are fantastic! Even when read by a frantic mom at two am!)
<The fry need identical care to the adults.>
Thank you again for your time and care. I know I and my small daughter have already learned so much from your site. God bless!
Tricia in PA
<Cheers, Neale.>

Re: Mollies, freshwater plants and fixing my mistakes 6/30/09
Thank you so much for your fast reply.
<No problem.>
Am I to understand that the high GH with moderate KH is normal?
<Yes. General hardness plus carbonate hardness makes total hardness; the two things are not actually proportionally related to each other, though yes, water with a high General hardness tends to have a high Carbonate hardness too.>
(I had assumed that the two tended to be nearly the same... though I cannot be certain where I picked up that tidbit of information (or misinformation!)).
<Never mind!>
As I *do* have such hard water and moderately high Ph, can I get by permanently with the low SG of 1.001?
<Quite possibly. All depends really. If the water is clean, the nitrate is low, and the pH is stable, then yes, Mollies should do well within minimal, some would argue zero, salt.>
If so, I understand from another part of your site that my plants should do fine. This will be sufficient for the mollies?
How can I measure my salinity? The hydrometer available at the LFS (yes, sadly, I do need to keep shopping there, there is no where else to go... but most of my equipment etc. all comes from online shopping anyway) will not read this low of a salinity (specific gravity). I believe, if I remember correctly, that the lowest marked point is 1.015 - far too high for my purposes.
<A basic glass hydrometer calibrated for 25 degrees C should work fine; these cost $5. If you look on my web page, you'll see a little Mac/Windows application that helps you see how salinity, specific gravity, and
temperature are related. Http://homepage.mac.com/nmonks/Programs/brackcalc.html
You're aiming for about 3-4 grammes of marine salt mix per litre.>
Any further suggestions? I really do wish to be a good "fish mother".
Especially as this is meant to be a teaching opportunity for my daughter as well.
As for the other fishes, I will begin working on another situation for them. And, of course, beginning a search for the fish you suggested for algae control (Florida flagfish - I am just beginning to research these
now. I have been waging a war on snails in the tank - perhaps I should just let them be?).
<Snail populations grow proportionally with the food in the tank: uneaten fish food, fish faeces, and dead plants. Keeping the tank clean, siphoning out waste (a turkey baster is a great tool for spot cleaning!) and removing dead plant material goes a long way to "starving" snails. The less food, the fewer the snails. Add a few Clea helena if you want a good, safe snail predator.>
Thank you again for your suggestions. I am very grateful. It is so rare to find a website with real, clear information and kind folks who take the time to disseminate it. Thank you again!
<My pleasure. Cheers, Neale.>

Mollies & more 3/27/2009
Hi WWM team. Your site has helped us but I have some Q & comments.
<Fire away!>
1. Why do you not advise adding limestone for mollies instead of salt?
<We (I) recommend neither. I specifically recommend marine salt mix, which takes care of the carbonate hardness, pH and salinity issues all at the same time! Limestone can be added to aquaria, but it raises carbonate hardness by an unpredictable degree. Do you know how many pounds of rock to add per gallon of water to get a hardness of 10-20 degrees dH, a carbonate hardness of 7+ degrees KH, and a pH steadily holding at around 7.5? Nor do I. Moreover, because limestone gets covered in algae and bacteria over time, it loses its buffering capacity. (Think of how the candy shell of an M&M prevents the chocolate from melting in your hand; it's the same thing.) So unless you take all that rock out every couple of weeks and clean it, over time, it'll benefit your Mollies less and less. Crushed limestone and crushed coral in an undergravel filter are better in the sense of having much of surface area in contact with the water, but they still lose their buffering capacity over time. The addition of marine salt mix is therefore a cheap, easy way to get perfect Molly water every single time! 5-6 grammes per litre does the trick nicely. It's a no-brainer.>
2. Why doesn't Bob like Melafix?
<Because Melafix doesn't work reliably. We give advice that we know works, or at least, works most of the time. Melafix (at best) works *sometimes* on mild infections. You'll note that neither MDs nor veterinarians recommend tea-tree oil for treating fungal and bacterial infections. Neither do we.>
3. I read a Q from an experienced fish keeper about a new tank where the water went white and was too warm and the fish went crazy. She had used nice established water from her main tank. We had the same thing. The clues are temp too high, the 'whiteness', and bubbles forming on the glass as well as the fish going crazy and 'gasping'.
<Ah, yes, sometimes water can go "white" under these circumstances. What you're describing is oxygen coming out of solution when water warms up. It's the same reason why a glass of cold water put by your bed at night will have bubbles around the glass by the morning. Water holds more oxygen when cold than when hot, so as temperature goes up, oxygen dissolves out. Most of the gas bubbles away into the atmosphere, but some will adhere to imperfections on the glass, which is what you see. Now, this is absolutely not the reason most tanks go cloudy. Usually when aquaria have cloudy water
it's a silt issue or a bloom of either bacteria or algae.>
She did not mention the bubbles. All are signs of 'flat' or semi-boiled water such as might be seen in water from the hot-tap when put into a drinking glass. Is this not well known?
<It happens, but to be honest the temperature variation in most aquaria should be trivially small because of the heater. Sure, if you add fresh cold water and then add the heater and warm it up, you'll see bubbles on the glass. But an established tank at the usual 25 degrees C won't experience this (unless the water has become supersaturated with oxygen at some point in the filtration/circulation cycle).>
I was surprised she had not seen this in her years working in pet shops and WWM put it down to 'new tank syndrome' with no further explanation and told her to clean the tank with bleach and the necessary follow up. Good advice to ensure all foulness was gone, however the new aerated water is the real solution.
4. I am confused as to the best way to kill a fish if needed as WWM guys seem to differ on this.
<This is a part of the hobby with much misinformation, and certainly things I considered humane twenty years ago are now known to be anything but! So for example the use of ice is now considered to be stressful to the fish and not recommended. Articles on WWM are anything up to ten years old, perhaps more, so in some cases advice offered in good faith then would now be considered inappropriate. Do read here:
The article is based on current scientific and veterinarian practise, rather than hobby anecdote.>
Keep up the good work. S
<Thanks. Cheers, Neale.>

Re: mollies & more (Euthanasia; cloudy water; Melafix) 3/27/2009
Great answers! Thanks Neale. I should have specified I meant marine salt, I am txt-ing and got lazy.
<No problems.>
Apparently the amount of limestone rock doesn't matter as it will only raise the carbonate hardness etc. to a specific level and only if they drop will more release.
<Ah, yes, limestone will not raise the pH above a certain level, but if you don't have enough, it won't dissolve fast enough to compensate for background acidification or the addition of soft water during water changes. So there is an optimal level balancing quantity against efficacy.>
Sorry, I didn't do the research, my partner did prompted by the fact that mollies are kept in fresh, brackish and salt aquaria, he is also the one with the scientific mind and he could explain more scientifically. Aquaria mollies apparently are descended predominately from limestone caves from Mexico (if memory serves, again his research) although found elsewhere including mangrove swamps.
<There have been numerous theories about where the domesticated Molly comes from, none of them completely convincing. The flip side is that feral Mollies -- that is, aquarium Mollies released into the wild -- have become established in all kinds of habitats, including the sea (Gulf of Thailand) and freshwater streams ( Australia, California, etc.). So in the wild at least, where water quality is much better than in aquaria, salinity doesn't seem to matter much. It's in the aquarium where Mollies become delicate, and where the addition of salt is usually recommended (though not all experts agree on this, I accept).>
We have a molly only tank so we have the luxury of being able to create conditions specific to them. There are a couple of benefits limestone offers mollies that m/salt does not or in much reduced amounts such as magnesium.(I should have done the research myself!)
<Marine salt mix should raise carbonate and general hardness substantially, and I can't see precisely what limestone would do differently, or better.>
As much as I think my man has a brilliant mind I'm not adverse to another opinion or two.
The other reasoning for limestone rather then salt was maintaining consistency of water state (I note your 'unpredictable' comment) as they can adjust to a water state but don't like to have adjust their internal biological state all the time for external changes (owner stuff ups-the same reason for choosing fish that suit local water ph rather then using ph up/down). Limestone is cheap as chips here too, even compared with m/salt. My mollies are far more resilient with it. I will be discussing your advise in the morning though.
<Ultimately the only way to settle this is experiment. Simply experiencing one set of conditions and assuming it is the ideal can be misleading. If you had three tanks, one with limestone, one with marine salt mix, and one with neither, and then ran all three tanks for six months, then we'd perhaps have grounds for a scientific research paper! As it is, while your approach may well work extremely well, it's difficult to know how to generalize that outwards to Molly keeping generally.>
As for tea tree there are many different types of plant that fall under this term and the one used for Melafix is a paperbark that grows in mangrove swamps and it is different to the tea tree commonly prescribed by both MDs and vets here in Australia.
<It's Melafix that Bob and I tend to rail against. I've not used Melafix -- I admit -- but I've received a lot of mail here at WWM from aquarists who have treated sick fish with Melafix but their fish have failed to recover. I'm open minded to its value as, say, a preventative, but it wouldn't be my "drug of choice".>
It certainly helped our Betta who came from the shop with curls and a fungus (live and learn).
Again, here in Oz ordinary cold tap water is regularly 'flat' straight from the tap due to our high temps (today was a cozy 36C coming into autumn) a mistake we only made once.
<Here in England, the water is a good deal chillier than that out of the tap! When I use rainwater, it's often barely above freezing, and you have to be careful adding small amounts of that to tropical tanks or the fish go rather doolally for a while.>
Thanks for the link, sadly we made a bad choice of a pair of red fin sharks when starting out based on pet shop advise.
<Oh. There are few "sharks" that are genuinely good community fish, and unless there are facts to the contrary, I tend to recommend casual aquarists against them in favour of things like the smaller Garra species or the Siamese Algae Eater.>
You have as usual been very helpful. Thanks again.
<Most welcome. Cheers, Neale.>

Planted or brackish for mollies... 3/9/09 I love your site! I could read on for days! Anyway, I have a 12 gallon brackish tank with 4 mollies and 2 guppies. Nitrite 0 nitrate around 20 give or take. PH 6.7 fish are healthy Twice weekly 20% water changes I am looking into creating my tank into a planted tank but I have some questions... Will my mollies be fine in a planted tank rather thank a brackish tank? Is my 13 watt bulb enough for some easy plants? (Java fern, tape grass, moneywort, dwarf Anubias) If I do decide to plant what is the best thing to do with my fish while the tank cycles? (I have a molly friend that lives near and a couple teeny tanks-1 gallon and 2 gallon...) I am worried that the tank will look murky and "lettuce bowl" like - not like some of the really nice ones I have seen. Is there a way to prevent that? How can I prevent snails and or snail eggs from getting into my tank? I have heard "picking at it" "Shaking eggs off" "dips" "water treatment" Which is best? Thanks a bunch! Hannah <Hello Hannah, and thanks for the kind words. The short answer is there is nothing to stop you having a planted brackish water aquarium. Lots of aquarium plants naturally come from brackish waters and if all else is equal they will thrive under such conditions in an aquarium. I keep a list of some of the best species on my Brackish FAQ pages, so stop by and take a peek: http://homepage.mac.com/nmonks/Projects/FAQ/2d.html That said, at barely 1 watt per gallon, you're going to be hard pressed getting any plants to grow in your aquarium. Most plants need around twice that amount of light to do well. Java moss, Java fern, Anubias, and perhaps some of the hardier Cryptocoryne species are the best choices. Sometimes Vallisneria adapts to low-light conditions, but it's hit and miss. Moneywort is a non-starter; it needs a lot of light. I'd suggest sticking with epiphytic plants (Java moss/fern, Anubias) for two reasons. Firstly, they're good choices, but secondly, they don't need a fancy substrate. They get their nutrients from the water, unlike plants with roots. This will mean you won't need to fill the bottom few inches of the tank with gravel and aquatic soil, leaving more room for the fish. As for snails. I don't see them as a problem. Tanks with snail plagues usually have other, more serious problems. Snails convert uneaten food and organic waste into baby snails. If the tank is basically clean, there's little for the snails to eat, and they breed slowly, more or less at the same rate as they die or get eaten by other fish. That said, I know some people have snail phobias. In this case, the best approach is to clean plants before they are put in the tank. You can buy snail-killing potions over the counter, and all you do is make up a bucket of stuff, stick the plants in there for a certain length of time, and then remove the plants knowing that they are snail-free. http://www.wetwebmedia.com/plantedtkssubwebindex/snailsags.htm Never, ever add snail-killing potions to an aquarium, even if the package says the chemicals are safe for fish. While the chemicals themselves may be harmless, lots of dead snails all rotting simultaneously will do nothing to improve water quality! Cheers, Neale.>

Poecilia/Mollienesia (health, water quality) 2/10/09 Hi, my name is mike. <Hello Mike,> I have a white balloon Molly that is sick. My water parameters are: pH is 7.2, Ammonia is 0 ppm, Nitrate is 5.0 ppm, Nitrite is 0.25 ppm. The tank is a 20 gal. freshwater with no salt at all. <Well, there's the first problem. The tank is too small and has the wrong water for Mollies. Mollies need big tanks because they are sensitive to poor water quality. You have poor water; ergo, your Mollies will get sick. In fact the nitrite level is way too high for any aquarium, and you need to URGENTLY review feeding, stocking, and filtration. Your tank will never work correctly with 0.25 mg/l nitrite: fish will constantly be getting sick. As you mention salt, you probably realise Mollies appreciate salty water. It isn't essential in a well-run, big, clean tank with hard, alkaline water -- but your aquarium is none of those things. The addition of marine salt mix (not tonic/aquarium salt!) will raise the pH, hardness, and salinity to levels that favour Mollies, and indeed many other livebearers as well.> The tank is shared with two Goldfish, One Dwarf Gourami, One Angel fish, two Platy's and two Cory's. <Platies are good companions for Mollies, Goldfish potentially so, but the others shouldn't be here because they don't really like brackish water. Up to around 3 g/l, both Platies and Goldfish will do fine.> None of the fish nip at each other and all look well after almost three months together (after cycling for a month) The Molly, just one day ago, has been laying on the bottom of the tank breathing very shallow, not eating and not passing waste, listing and swimming nose down on occasion and backwards sometimes, but every once and awhile will swim just fine and go to the surface (but very rare) the fish looks like it's paralyzed to a degree. <Shimmies or equivalent... dying...> The Molly has Been in a separate tank for about 20 hours now, filled with some water from the original tank and some new water, both tanks have identical water and the filters are the same with an air stone working off the same air pump as in the larger tank. I've looked through most of the site about Mollies and some about Angel fish, and found similar but not the same symptoms. I feel horrible for the poor thing and was wondering if there is anything at all I could do to help it. Thank you in advance for the help trying to make the fish better. <Angels and Mollies are not compatible. Review the needs of Mollies, set up a tank as required, and enjoy better success. http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Cheers, Neale.>

Re: Poecilia/Mollienesia (health, water quality) 2/11/09 Thank you so much for your reply and the advice you gave, but unfortunately the molly didn't make it. I feel horrible that my incompetence killed an amazing little fish like that. <Not incompetence, merely lack of knowledge. Do read a fish encyclopaedia before spending any money: it's pretty widely known Mollies like a little marine salt mix in their water, and while not essential, it does make them much easier to keep. Because of this requirement, I recommend keeping them with species that tolerate or enjoy a little salt too, such as Platies, Swordtails, or Guppies. Indeed, most any livebearer will do well. Australian Rainbowfish and many Killifish also fall into the salt-tolerant category, so it's really not that big of a deal. A box of Instant Ocean marine salt mix will last months at the required dosage, so it's a lot cheaper than [a] buying new fish and [b] buying fish medications.> I bought a larger tank yesterday afternoon (along with a canister filter and new sandy substrate) and look forward to creating a much better environment for the fish that have me and my family glued to the tank for hours at a time (well maybe just me most of the time) <Ah, a tank with a sandy substrate opens up LOTS of options, such as Gobies. Look up Knight Gobies (Stigmatogobius sadanundio) and Violet Gobies (Gobioides broussonnetii) as examples. http://www.wetwebmedia.com/brackishsubwebindex/knightgobyfaqs.htm http://www.wetwebmedia.com/brackishsubwebindex/bracgobioids.htm They need brackish water, and positively THRIVE alongside Mollies at, say, SG 1.005 (about 9 grammes salt mix per litre). Violet Gobies are big, ugly but really funky animals that make great pets. Faces only a mother could love! Watching them filter feeding on live brine shrimp is one of the most fun things in the hobby. They're gentle giants, and won't even eat livebearer fry if properly fed on worms, crustaceans and the odd algae wafer.> I do thank you for the advice and all the priceless information you guys diligently dole out about such a great hobby and hope that one day I will be able to help someone with as well. <We're happy to help.> Thanks so much Mike
<Cheers, Neale.>

Liberty Mollies, sys. 2/2/09 We have two female liberty mollies. When we purchased them we were told that they were freshwater mollies. We have learned since then that most mollies prefer brackish water or salt water. My question: Is it true that liberty mollies will do well in fresh water? Thanks for your time! Debbie <Debbie, The Liberty Molly (Poecilia salvatoris) is a true freshwater species -- but then so are ordinary Mollies like Sailfin Mollies and Shortfin Mollies. The problem is that what fish need best in aquaria isn't necessarily what they experience in the wild. Slightly complicating matters is that for many years the Liberty Molly was not recognised as a distinct species, and was assumed to be a mere variety of Poecilia sphenops, so aquarium books usually say very little about this species. Now, having said all this, like most Mollies the key things are probably water quality and water chemistry stability. Very hard water (certainly upwards of 15 degrees dH) with a stable pH somewhere between 7.5 and 8 is what's required. Water quality must be excellent, with zero ammonia and nitrite. Nitrate is also an issue, and I'm increasingly of the opinion that what makes or breaks Mollies in freshwater tanks is not the lack of salt as such, but dangerous levels of nitrate. Sodium chloride reduces the toxicity of nitrate, and so in salted water Mollies are not sensitive to high levels of nitrate. What's a high level of nitrate? Probably anything around 20 mg/l or more, if nitrate sensitivity among cichlids and marine fish is anything to go by. Liberty Mollies are very active, apparently fast-water fish, so water current and oxygen are likely to be important. My hunch is that if you got all these factors right, you might not need to add any salt at all. On the other hand, if things weren't quite right and your Liberty Mollies were prone to fungal infections or Finrot, then the addition of a small amount of marine salt mix would stabilise the pH and reduce the toxicity of the nitrate. You don't need much for this effect; around 3 grammes per litre should be ample. At that level, you could easily maintain them alongside other livebearers. Swordtails for example come from a very similar habitat. I'd avoid mixing them with any Poecilia species (Mollies or Guppies) because of the risk of hybridisation. What a tragedy it would be if you lost out on producing good quality offspring from this beautiful and rarely maintained species! Please do breed them carefully, and share the offspring with other fishkeepers. Cheers, Neale.>

Re: Liberty Mollies (Environment; salt) 2/4/09 Thank you so much for the valuable information. Here is a picture of one of our mollies! <Happy to help, and thanks for the picture. Looks like a nice, healthy female. Both sexes will colour up nicely as they mature, but take care to include algae and small crustaceans (such as daphnia or brine shrimp) in their diet, as these are keys to bright colours in fish. Cheers, Neale.>

Hello, brackish salinity question 01/13/09 Hello again, After much consideration, I have decided to change my tank to brackish for my mollies. Most websites I go to say 1/4 cup per gallon. is this ok? Thanks! <Hello Rachel. The ideal salinity for Mollies is between 6 and 9 grammes per litre of water (about 0.8 - 1.2 oz per US gallon). The resulting specific gravity is 1.003 to 1.005. This is low enough that your filter bacteria will quickly adapt without fuss, but salty enough the Mollies will be palpably healthier and hardier. While you are free to find out how many grammes (or ounces) of your particular marine salt mix fit into a cup, once you've made up your salty water, you should use a hydrometer to check the specific gravity. A basic floating glass model costs about $5, while plastic swing-arm models are a bit more expensive. Why check the specific gravity? Because once a box of salt is opened it absorbs water from the atmosphere. Over the weeks, each teaspoon or cup or gramme or ounce actually ends up being partly water, so that going by those measurements alone you'll be underestimating the amount of salt added to each bucket of water. The variation isn't too serious if you keep the bag of salt tightly closed inside an airtight container, but it's worth checking nonetheless. You can also use your hydrometer to check the specific gravity of the aquarium itself. During summer especially, evaporation will cause salinity to rise as water evaporates away. The Mollies won't care much, but any plants in the tank might, and the filter bacteria certainly don't like dramatic changes in salinity. Cheers, Neale.>

Caring for mollies 12/30/08 First, let me say that your site is wonderfully helpful. I am brand new to caring for fish and have spent hours upon hours on the internet looking for help, and this is the first truly helpful site I have found. <Thanks for the kind words.> Two weeks ago, I inherited a 30 gallon aquarium with 23 or so small fish. 3 are male black mollies, about 20 are Dalmatian mollies (more females than males, although it's difficult to count them), and two small fish that I can't seem to identify. I have searched the internet and asked at the local pet store, but no one seems to know. They are orange, about an inch long, and they have a few very thin white stripes running the length of their bodies, and round bellies. Their fins are almost transparent. (Also--one of the Dalmatians is a baby, not quite 3 weeks old). <Quite possibly "balloon" Mollies.> The person who had the fish before me did not take proper care of them. The filter had never been changed (at least 6 months), the water was rarely changed, and the fish were being seriously overfed. They died regularly, and they were regularly replaced with new fish. I was told that only two (the orange ones) are "originals," and that there have been two successful pregnancies. Most of the first fry survived (12 fish, I think), and only one from the second. I don't know if that information makes a difference.... <Oh dear. Do start here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Maintenance of Mollies is not difficult, but frequently "done wrong".> I am doing my best to keep up with the cleaning--thankfully, I have not lost any fish. I took some water to the local pet store and a "fish expert" there tested the water and told me everything looked good, and that I should change 10% of the water once a month <Too little... 25% weekly more sensible. The "10% per month" is how the hobby was done 25 years ago. We've moved on... and the fish live longer for it.> and add bacteria like StressZyme <Redundant... he's trying to sell you stuff... Once the bacteria in the filter are established, they'll last the lifetime of the tank. No need to add more.> and a handful of salt with each water change. <A "handful"? Pretty meaningless. Instead, go for 5-6 grammes of marine salt mix per litre.> She also showed me how to change the filter (which was disgusting, as it had never been changed before). <Every couple months, give the filter media a rinse in a bucket of water taken from the tank.> I have been keeping up with everything as instructed. The male black mollies were very aggressive, <Yes, male Mollies are...> and the pet store suggested that I get 3 female black mollies for them to mate with. I was relieved when the aggression completely stopped, in less than a day. (So now there are, I believe, 26 fish). <OK.> Also: the water temperature fluctuates between 76 and 78 degrees. <No big deal.> The heater is on as high as it goes. There are also some live plants, one fake plant, and two decorative items, all of which the fish LOVE. I was told the rocks weigh about 40 pounds, but I am not sure if that is correct. <Oh.> The day before yesterday, the fish started acting sluggish. They weren't really swimming much (other than two of the males who are constantly trying to mate). Most of them have not been interested in food, either. I am extremely careful not to overfeed them. I had changed the water about a week and a half before, but I thought something might be wrong with it. I tested it today, and the nitrate and nitrite levels were both high ("unsafe" according to my test strip comparison chart). I followed the directions for adding salt and bacteria, and I changed about 25% of the water according to what I read on this site. In 5-10 minutes, the fish completely perked up! As I had cleaned out the debris from all the food they hadn't eaten, I fed them again and they ate with appetite. I was happy to see this. <Mollies are highly sensitive to Nitrate, and in freshwater tanks tend to get sick at nitrate levels above 20 mg/l. Nitrite and ammonia are both toxic to them, but in brackish and marine conditions they tend to be much hardier. Changing water reduces concentrations of all three chemicals, hence the fish "perk up". Marine salt mix contains sodium chloride, and to some degree this detoxifies these chemicals as well. Plain aquarium salt (the kind not used in marine tanks) does this too, but it doesn't have the second benefit of regulating water chemistry by raising the carbonate hardness, hence my advice to opt for marine salt mix, and not to waste your time with aquarium (tonic) salt.> But now, several hours later, I tested the water again just to make sure it's okay. The levels seem to have gotten worse. This is what the strip reads: Nitrate: between 80 and 160 <Extremely bad.> Nitrite: between 1.0 and 3.0 <Dangerous.> Hardness: 150 Alkalinity: around 80 pH: between 7.8 and 8.4 <pH variation is too much; marine salt mix at the dose described above will fix this.> Another thing I have noticed, in the past week or so, they have been spending a lot of time near the surface. They splash a lot, which is something they did not do before. The past couple days, they would crowd together up at the top of the aquarium, barely moving, until one would "jerk" and the others would literally jump to get away. Since I changed the water today, they haven't done this at all, but there is still a good deal of splashing. <The water quality is extremely poor. The tank may be overstocked, but is certainly under-filtered and not receiving enough water changes. Unless there is zero ammonia/nitrite, and sub-50 mg/l levels of nitrate, your water isn't safe.> What should I do? Forgive me if the answers are elsewhere on your site. <They are; but do start at the Mollies article listed above.> I have tried to read it thoroughly, but there is terminology I do not understand. I am so completely new to this! For now, the fish seem okay--worlds better than before. They are swimming around, and about half of them are pecking at the gravel, looking for food. I am just concerned about the results of the water test. Any help you can offer I really appreciate. Thank you! <Most welcome.> Amelia <Cheers, Neale.>

Black mollies... Hlth., sys. 11/14/08 hi i have two black mollies and one has white discoloration on him and i understand it could be a fungus and i should do a 50% water change and use Maroxy to help and add a tea spoon of salt to my tank but im worried for my other fish i also have guppies and other mollies and platys will the Maroxy or the salt harm them? <Greetings. Guppies, Mollies and Platies will all do well in brackish water. Maintain this aquarium at SG 1.003 (6 grammes, about one teaspoon, or MARINE salt mix per litre of water). Understand this: aquarium or cooking salt won't help. You need to be using marine salt mix, i.e., products like Instant Ocean or Reef Crystals. These not only add salt, but also raise the pH and hardness levels. Black Mollies, and indeed all Mollies, do best in brackish water and almost always get sick in precisely the way you describe when kept in freshwater tanks. http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Cheers, Neale.>

Questions (Mollies; community tanks; water chemistry) 10/21/08
Hello, hope things are going well for you today. I have a couple of questions, please. First, when purchasing swords and/or mollies I know it is best to have several female to one male, but if you have say 2 species of mollies, is it OK to get 1 male of each species or do you just get 1 male molly period?
<Males of all livebearer species fight with each other. It's your call whether you keep a single male or a dozen males where no one fish can become dominant. But twos or threes rarely work, with one male becoming dominant and the others being terrorised. Personally, I like my fish to be happy, and would ALWAYS recommend keeping livebearers in groups of one male to two or more females, and multiples thereof. If that doesn't appeal because you want "one of everything in the shop", then don't keep livebearers.>
Also, please tell me the ratio of male to female for rainbowfish and how to tell the difference.
<With rainbowfish you can't normally sex juveniles of most species. There are exceptions like Glossolepis incisus. In any event, you want equal numbers of both to minimise bullying and ensure the males colour up once they mature. So buy six, three of each sex if possible.>
Lastly, do you feel mollies are fairly hardy fish to keep for beginners?
<Absolutely not. Mollies are extremely difficult to keep in freshwater and would never, EVER recommend them to beginners with a freshwater tank. At best, 50% of them seem to get sick or die when kept in freshwater. Please review our Molly FAQs for some of the horror stories. If you don't want to keep a brackish water community, don't keep Mollies. There are plenty of other large livebearers. Swordtails look great, though the males are even more aggressive. Limia nigrofasciata is a lovely fish with a "sail fin" and the males get a humped back that makes them look quite funky.>
I know they require a higher PH than some fish. Could I keep them with rainbowfish and Corys and a couple of Kribs, and if so, what would you recommend for the ph to be?
<Rainbowfish, Kribs and Mollies could all be kept in a slightly brackish water aquarium at SG 1.003, pH 7.5 or so. The only problem is that when the Kribs breed (which they will!) you will get mostly male fry because sex is determined by pH. If you were going brackish, I'd actually recommend Etroplus maculatus as a colourful, hardy cichlid for the community tank.>
I know they sell stuff to make it neutral.
<Unless you're an expert fishkeeper, don't even think about altering water chemistry. The fact you've asked about pH and not hardness suggests to me you don't understand the topic. Realise this: pH is not important, hardness is. We measure pH because it's easy, not because it's important. Beginners often mistake pH for something fish care about, but they don't. Most fish can tolerate a wide range of pH values without complaint. But they are often much more specific about hardness.
Much better to find out whether you have hard or soft water, and then select your fish accordingly.>
Thanks so much.
<Cheers, Neale.>

Re: Questions (Mollies; community tanks; water chemistry) 10/21/08 Hi Neale, <James,> So as far as livebearers go, if I have 2 different types, say swords and platies I can get a male for each type as long as I have several females of the same type, i.e. 1 male sword-3females and 1 male platty-3 females? <Correct.> Not just 1 male period for the whole group? <Like one male Swordtail and two female Platies? That would work, too.> Also if I have 3 different species of swords <All the traded Swordtails are a single species, just different varieties. Like Dobermans and Poodles are all dogs, however different they look.> would I be able to get 1 male of each species with several females of each or just 1 male sword period? <So long as you have one Xiphophorus helleri male and multiple Xiphophorus helleri females, it doesn't matter if they're Red Swordtails, Green Swordtails or whatever.> Do I have to have brackish water for rainbowfish and Kribs? <Nope; both these fish prefer neutral, moderately hard water. They just happen to tolerate slightly brackish water.> If so I will disregard them because I want to keep cories and I have read that since they are scaleless they cannot tolerate salt. <Corydoras will tolerate small amounts of salt (SG 1.001-1.002) just fine according to the likes of Dave Sands, noted catfish expert. That said, for the brackish water aquarium I'd always recommend the salt-tolerant catfishes such as Hoplosternum littorale. The "absence of scales" is irrelevant, since lots of marine fish, like eels and sharks and puffers have no scales.> When picking out a pair of Kribs do I have to get 1 male and 1 female or will 2 of the same sex be OK? <Both males and females can be aggressive. Therefore it's best to get a boy and girl, and let them pair off. Singletons are fine, by the way, and a group of females wouldn't be a bad idea. Since the girls are prettier than the boys, there's no loss. I keep a female Pelvicachromis taeniatus in one of my community tanks.> And do you feel Kribs are ok for beginners or should I get another kind of cichlid? <They're one of the best "beginner" cichlids. There are others though; do read around. Cheers, Neale.> Do you recommend putting aquarium salt in a fw tank? <Not unless you're keeping brackish water fish, no. Cheers, Neale.> So if I get 2 or 3 females of the Kribs that would be OK? <Should be just fine. There might be some scuffles over hiding places, but nothing too serious. Introduce them all at the same time to minimise the chances of any one fish becoming a bully. Obviously they won't breed, but that's no loss; breeding Kribs is just too easy, and most pet stores will reach saturation point of baby Kribs before too long! Cheers, Neale.> Please tell me the best way to dechlorinate my tap water before making water changes in fw tank. I read an article on your site but was kind of confused. <In what way were you confused? Seems pretty obvious to me: add dechlorinator as instructed on the bottle. If your water has chloramine in it (your water supply can tell you this) be sure and use a dechlorinator that treats chloramine (most do these days, so it's not really a big deal).> Also, what type of resin or carbon is best for chemical filtration? <In freshwater tanks, chemical media are largely redundant, except in a few exceptional circumstances. For most community tanks it's best to concentrate on biological and mechanical filtration. Cheers, Neale.>

Re: Questions (Mollies; community tanks; water chemistry) 10/22/08 Hello Neale, <James,> Please excuse me for all of the questions. I was not trying to be rude. I suffer form OCD and when I get going on a particular thing it is hard to stop. <Oh, okay.> Not making excuses. Just letting you know I really am one of the most polite people around. Have a good day!! James <No harm done. Have a good day yourself! Cheers, Neale.>

Balloon Mollies - One of 'em not mixing (Behaviour; environment?) 10/17/08 Hi, <Hello,> We've recently bought three balloon mollies (One male, two female). The male and one of the females are instantly pals, always shadowing each other and playing. <No, they're not playing. The male is trying to mate, and more than likely the female is trying not to! It's always dangerous to anthropomorphise when talking about animal behaviour. Most animals I know get very offended when I assume they think like humans!> They were quick to begin exploring the tank after being introduced. The other female however, does not join them. She seems to spend a lot of time against one side of the tank. She's not up at the surface, nor hiding from sight. She just keeps going up and down as if she's searching for a way out. They are the first 3 fish in a 30 gallon tank. The water properties are good (7.5ph, 0.25ppm nitrate current, 81 degrees F) <Hmm... do you really mean "0.25 ppm nitrate"? That's very low, and not many consumer-grade test kits register such tiny amounts. If that's 0.25 ppm nitrite (note the "I" in there, as opposed to the "a" in nitrate) then we have a whole different ball game. Mollies are incredibly sensitive to nitrite, particularly if (unwisely) you have opted to keep them in freshwater conditions (which, frankly, hardly ever works out well). If you have a nitrite level that is detectable, then you have too much, and Mollies respond by getting sick, and then dying. Consider them "miner's canaries" if you like. If this is a new aquarium, I'd heartily recommend switching to slightly brackish conditions by adding marine salt mix (Instant Ocean, Reef Crystals, etc.) at a dose of, say, 4-6 grammes per litre. Sodium chloride has a useful property of undoing some of the damage caused by ammonia and nitrite, and marine salt mix also contains other minerals that buffer the pH and hardness. Net result, Mollies thrive instead of survive. This low dose won't harm your filter. Since Balloon Mollies shouldn't be mixed with any other type of fish, the fact you're adding salt isn't an issue in terms of tankmates. Problem solved.> Now, she is white and the other two are black, can that be an issue? (the two black ones seem to gently 'recruit' her away from the side of the tank from time to time) <Nope; all the same species, or likely hybrid.> Also, she is significantly more plump then the other two. If she's pregnant, will she be anti-social? <Nope.> Thank you in advance, Nick <Cheers, Neale.>

Re: Balloon Mollies - One of 'em not mixing (Behaviour; environment?) 10/19/08 Hi Thanks for the prompt reply. <Most welcome.> First off, I did mean 0.25ppm Nitr[I]te. I'll admit, we only allowed the new tank about a week and a half of cycling before getting the mollies. We figured three of them in a 30 gallon would help speed the cycling process (with daily partial water changes until it settled). <Then that's why your Mollies aren't well. Case closed. Mollies just don't tolerate nitrite or ammonia well, at least not in freshwater conditions.> As far as the salt goes, we have very slightly brackish water (about half the recommended treatment - so a tablespoon per 10 gallons) as we did intend for this to be a community tank. <This isn't "slightly brackish" anything. Slightly brackish is around SG 1.003-1.005, 6-9 grammes per litre. Six grammes of salt is about one level teaspoon, and one US gallon is 3.75 litres. So if my math is correct, SG 1.003 is about 22.5 grammes of marine salt mix per US gallon, or just under four teaspoons of marine salt mix per US gallon. Ten US gallons would therefore need 4 x 10 teaspoons = 40 teaspoons, and 40/3 = 13.3 tablespoons of marine salt mix. Your dose of salt is quite obviously not nearly enough to make a difference. I just can't stress strongly enough how important it is for Mollies to be kept -- long term -- in brackish water.> (plans were for two angels, three mollies and 5 or 6 medium tetras/Danios/somethin'rathers) <Forget it. Mollies don't work with these fish. Instead look for other brackish water (or at least salt tolerant) tankmates. Very many options, including Guppies, Halfbeaks, Limia, gobies, sleepers, certain cichlids, even certain catfish. Plenty on brackish water species at WWM.> However!... The white molly I wrote to you about gave birth and now she is social with the other two. Shortly thereafter, the black female went into hiding on the gravel, under a log and later that day, she started birthing too. I'm sure a number of 'em got eaten but we have spotted and netted 18 fry in all. We don't have a separate tank for 'em so I'm keeping them in the breeder trap for now. <Cool.> I guess I'll add the bit more salt and just look forward to watching some of these little ones grow up instead of getting other fish. lol Will they be okay in the breeder trap until they are large enough to swim free with the adults? <The babies will be fine with their parents once about 1.5 cm long, which should only take 6 weeks or so.> Nick <Cheers, Neale.>

I have a new white Molly in my aquarium. 9/25/08 <Freshwater or brackish? Do review the needs of this horribly misunderstood species.> It has been in the tank for a few days and seems to continually slide up and down one side of the glass in the tank. The ammonia and nitrite levels are at 0 and under 4mg/l respectively nitrates at zero. <Nitrites are FAR too high. Mollies are extremely intolerant of nitrite. If this is a freshwater tank, ammonia and nitrite should both be zero. In brackish to marine conditions (SG 1.003 upwards) Mollies will tolerate a bit more nitrite for a short while, but certainly you shouldn't be allowing this level to go above 0.5 mg/l. Be under no illusions on this: Mollies cannot be used to cycle freshwater tanks. Their mortality record under such conditions is incredibly high.> I was wondering if it had something to do with the reflection in the glass. The tank is roughly 60l or 15 US gallons. <Too small for Mollies. Please do review the needs of fish before purchase; Mollies are difficult to keep at the best of times, and really aren't sensible choices for tanks under 30 gallons.> Any advice regarding this behavior? thanks Bruce <Cheers, Neale.>

Molly question, sys. mostly 9/20/08
Hi -
I recently got 2 black mollies and 1 orange molly for my 8 gal. tank. The 2 blacks swim around together but the little orange one seems depressed - it comes out to eat, swims around by itself for awhile, and then goes down and sits on the bottom of the tank. It's fins move fine and there is no discoloration on its body. Someone told me it could be lonesome. Could this be true? I'm new to fish and would be happy to get it a friend.
<Hello Sharon. Mollies don't get "lonesome" as such; they are gregarious to some degree, but not compulsively so. Since you have three mollies already, they should all be fine. Now, the thing with Mollies is this: they're delicate and one of the first signs of ill-health is something called Shimmying, essentially where they stay in one place, often resting on the bottom, sometimes rocking, but almost always flapping their fins. It looks like they're treading water. So, if you have a Molly that isn't swimming about all the time, ideally grazing algae from rocks and plants, you may well (most probably) have a problem. Mollies need a big tank for a start: 8 gallons is simply not viable. You will need at tank AT LEAST three times that size to even begin to provide them with the space and water quality they need. Next up, they don't do well in plain freshwater, at least not in aquaria. You need to monitor in particular hardness and pH. Because most folks like to keep things simple, the easiest way to provide the right water chemistry is to add marine salt mix (not "tonic salt" or "aquarium salt"). Go ask your retailer for a box of salt of the sort used in marine aquaria. That's what you NEED. Add 6 grammes per litre of water each time you do a water change. That will make the aquarium slightly brackish, and your Mollies will be MUCH easier to keep. Do see here:
Cheers, Neale.>

Measuring salinity for mollies 7/29/08 Dear WetWebMedia crew, I'm preparing to set up an aquaria hub in my living room for breeding mollies. I want to try and keep the salinity around 20-25%, but I want to know how I can be sure of this during a water change. <25% seawater corresponds to about SG 1.005, or 7.5 grammes of salt per litre of water. If you download my Brack Calc program (Mac/Win) you can see how these three measurements are related to one another and to temperature. http://homepage.mac.com/nmonks/Programs/brackcalc.html Estimating the salinity this way is not very accurate though, because an opened box of salt absorbs moisture, and that in turn makes each gramme of salt mix actually rather less in terms of salt because some of that weight is water. So in practise you need a hydrometer or refractometer. A basic floating glass hydrometer costs about $5 and is accurate enough for this type of work *if used correctly*.> If I measure the water I am removing, and replace it with the same amount pre-treated with the appropriate amount of salt; the salinity will be roughly the same, right? <Correct. The important thing is to remember to REPLACE water taken out with brackish water, but TOP UP EVAPORATION with freshwater, because the water that evaporates doesn't take salt with it.> Thanks, Nick <Cheers, Neale.>

Re: Measuring salinity for mollies 7/29/08 Thanks for the tip! But one last thing- >>Correct. The important thing is to remember >>to REPLACE water taken out with brackish water, >>but TOP UP EVAPORATION with freshwater, because >>the water that evaporates doesn't take salt with >>it. Right so if I understand right, when I'm doing a water change, I want to replace with prepared brackish water, but if I'm just replacing evaporated water, I should use dechlorinated tap water. <Correct. This is exactly the same for marine fishkeeping, by the way.> Also, what's the safest way to take fish from the home to the LFS for trading purposes? <I use 3 to 5 gallon buckets with lids. But you can also re-use any plastic bags left over from when you bought some fish. Big (multi-litre) food containers can be used too. It doesn't really matter what you use, so long as the fish has enough oxygen and isn't exposed to huge temperature changes.> Cheers, Nick <Cheers, Neale>

Re: Measuring salinity for mollies 7/29/08 I noticed you all get this Q allot, but I noticed some inconsistency. For mollies, if I want to keep them in brackish water, will using API Aquarium salt raise the salinity or should I be using a marine salt mix, like Instant Ocean (the only one that I've seen at various LFS) instead? Cheers, Nick <For brackish water fish generally, you want to use standard marine salt mix (Instant Ocean, Reef Crystals, etc.) rather than tonic salt in the aquarium. Why? Marine salt mix contains not just sodium chloride but also a lot of carbonate/bicarbonate salts that raise the alkalinity and stabilise the pH, two things that Mollies and other brackish water fish really appreciate. Tonic salt (e.g., API Aquarium salt) is almost entirely sodium chloride, and while useful as a therapy (e.g., for treating Whitespot or doing "saltwater dips") it isn't a worthwhile long-term additive to the aquarium. To be fair, if you already have hard to very hard water with a high alkalinity (or carbonate hardness), then livebearers including Mollies won't be all that fussed, and you can probably get away with tonic salt. But I wouldn't recommended it, and I doubt it would be cost effective in the long term either. Marine salt mix, when bought in bulk, is inexpensive. Cheers, Neale.>

Re: Measuring salinity for mollies 7/29/08 Thanks for the advice (yet again), I'm glad to finally get a concise answer on the problem! :D <We aim to please! Cheers, Neale.>

Mollies and Gourami's: headed for disaster? 6/19/08 Hey crew, <Hello> You're site is beautiful and as a fellow website/ forum administrator, I can appreciate and enjoy lengthy pre-email checklist. <Sad that it is necessary.> I'm hoping this isn't a repeat. I am a college student who recently moved into my own (very tiny) apartment. I have always been fascinated with aquariums and planned to get one as soon as I got my own place, but have nearly zero previous experience, besides the handful of goldfish I won and promptly killed as a child at the fair. So about 3 months ago I waltzed into Petco and on the recommendation of the 'fish expert' I purchased a 5 gallon Marineland hexagon tank with a cartridge and bio-wheel filter and light attached to the hood, gravel, 2 flat river rocks, 2 good sized plastic plants, a small castle that has two caves. <Tiny> I set up the tank with bottled spring water and waited a week for the water to cycle. It passed the water test and I purchased (as suggested) a paradise fish, an Opaline Gourami and two Black Mollies. <Oh no> It was at this point (big mistake) that I decided to do my research and read through Freshwater Fish for Dummies. I now know the tank is way too small and our tiny Black Mollies need a tank with some salinity and are being bullied by the now much larger Gourami's. <Really it is too small for all of these fish, the paradise fish reaches about 4 inches, the Gourami about 6. The hex tank is probably not much more that about 8 inches wide I think.> One molly died a day or two after we brought it home and just wasn't eating from day 1. Now, 3 months later the remaining Molly has large white patches and white flakes coming out of her gills, which my research tells me is Columnaris (a common petstore Molly disease). I have been treating it for about 3 days with Maracyn 2 (as recommended on a few websites) and the patches have disappeared for the most part and the Molly seems fine. <Good, although the Maracyn most likely nuked your biofilter, so lots of water changes here.> The two Gourami's seem to be thriving. <For the moment, as they mature aggression will most likely follow.> They have grown inches and have gone from nearly white to very dark and rich in color. They seem to get along great and are very active and fun to watch, but they continue to bully the Molly who retreats to the castle cave or plants. <Expected.> I do a 25 percent water change on Sundays and change out a cup of water twice during the week. The tank is kept super clean and I use only spring water. I feed them color promoting flakes, veggie tablets and freeze dried blood worms in small increments throughout the day and I fast them one day a week. <Good> I literally do not have space in this apartment for another, or a bigger aquarium, but I plan on moving and getting one next year. Am I just wasting time buying medicine and special veggie food for this very stressed out Molly. <Probably, they are very sensitive in freshwater, best to find him a new home.> Will it just continue to get sick in these conditions? <Most likely.> Is it suffering or can I make this work for another 8 months? <Does not sound like he will last that long, can he be returned to the store?> I just want to know if I am torturing this fish by keeping it in this tank or can I keep it this way as a temporary situation? <It will most likely not survive much longer in this environment, and once it is gone the other 2 fish may turn on each other.> Am I a horrible person for doing this to these fish? <Not as long as you take steps to rectify the situations.> Give it to me straight please. <No holding back.> Cheers - Jacqueline <Chris>

Update on My Molly Tank & Marine Salt Use 05/25/08 Hi Neale, <Kathy,> The mouth/eye/body fungus problems seemed to be under control now. I have done seawater dip three times this week along with medication. It works very well. So, I want to thank you for your advice (although a few mollies acted miserably in seawater). <Yes, they may well look unhappy. But they won't be harmed.> Today I bought a bucket of marine salt (Brand: RED SEA). I am planning to switch Livebearer Salt to marine salt, but I have a question and hope you can help me. <Yes?> Our tap water PH is 8.2 (very hard water) because I live near Lime house and the water runs through lime. I am wondering if using marine salt will increase PH. <Seawater is self-buffering both against pH drops and pH rises. Adding marine salt mix to hard water should cause no problems with pH or hardness levels. Quite the reverse in fact, as you'll see many marine fishkeepers actively adding sources of carbonate hardness to artificial salt water so that they can raise the hardness and stabilize the pH even further.> I know mollies like hard water and high PH, but I am afraid higher than 8.2 can be a problem. <They won't be at any risk at all.> Thanks again! Kathy <Cheers, Neale.>

Aggressive Gourami & Molly Tank Salinity 4/5/08 Hi Neale, <Kathy,> A few questions about Gourami and molly... Hope to get some advices from you. <OK.> 1) I have 2 male Gouramis and 2 Cory catfish in a 15G tank... Though I have been thinking about adding a couple of fish, I almost have to give up this idea because one Gourami is very aggressive to all the other 3 fish. I am especially surprised he is aggressive to catfish. Is this normal? <Can be. Gouramis, particularly male Trichogaster trichopterus (the Three-spot Gourami) can be territorial. I personally don't recommend male Trichogaster trichopterus as a community fish. Other Gouramis are less commonly causes of trouble, though it does sometimes happen.> Knowing Gourami is sensitive to high nitrate, more regular water changes are applied to the tank. I try to do it quickly and make sure water temperature is the same; however, not matter how careful I am, one or both Gouramis would scratch against glass a few times during/after water change. I do not medicate them because this happens almost every time I do water change. So, I assume it's not really a parasite problem, just them being stressed a little bit. Is this very common? Is there anything I should try to do so they can be "HAPPIER"? <Don't worry about it. It is normal for fish to scratch themselves once in a while just as it is for your dog or cat to scratch themselves. Doesn't necessary mean there's anything wrong. You might check you're using enough/the right dechlorinator, because traces of chlorine or chloramine might irritate the fish without actually causing serious harm.> 2) A year ago I started this new hobby with 3 mollies. Now I end up with 200 fish!!! Fish keeping was totally new to me at the time and I did not read or do any research before I entered this new hobby. Fish store suggested me to get mollies to start the tank and I just took their suggestions. I guess half of beginners must have experienced the same problem as I do now. I keep all mollies in 3 tanks (38G/40G/65G males and females are separated now).... could be overstocked, but fish stores do not want to take them until they grow to certain sizes so they can sell them. With many fish in one tank, it's not easy to keep all of them healthy. My question is, if I see one scratch or seem to have mouth fungus, should I medicate the whole tank if QT is not available? I do not wish to use medicine if it's not absolutely necessary. These mollies are kept in brackish water (salinity: 1.003). Should I increase the salinity to 1.006? Will this help to get these problems under control? <SG 1.003 should be fine in terms of ensuring good health. Raising the salinity won't dramatically alter things. Mouth Fungus for example is bacterial and not affected by salinity at all. So yes, treat the tank with medication. You might want to get a bit more "cruel" in terms of how many fry you allow to survive. Most people who seriously breed livebearers end up with too many fry. Often they keep some sort of predatory fish to "dispose" of some of the fry. Angelfish for example are brilliant at this! But since you're keeping brackish water fish, you might enjoy something like Knight Gobies or Waspfish (Neovespicula depressifrons). These latter fish are utterly adorable puppy-like fish, and when you don't have fry, they happily eat earthworms and, with a bit of coaxing, frozen foods.> I cannot wait to see them grow bigger so I can give some away to the local fish store. <I know the feeling! But it's great when you get a bunch of money or credit to buy more aquarium stuff!> Thanks! Kathy <Cheers, Neale.>

Water quality.... 03/26/2008 I have mollies - 2 female and one male in a 10 gallon tank - just found 3 fry 2 days ago and they are in a crib <Congrats on the babies. But 10 gallons is well below what I'd recommend as even adequate for Mollies, let alone idea. Mollies are big, high metabolism fish and they like to have space to swim. A 10 gallon tank just isn't going to cut it in the long term.> Frequent water changes have kept these guys happy for quite some time (all play and eat, and argue from time to time) but my question is water quality has been perfect until about 2 weeks ago- dip stick now shows nitrate and nitrite - daily water changes and testing- with conditioners and salt cannot seem to fix this?? <Neither salt nor water conditions would impact water quality. Why should they? Rather, the fact your fish are [a] growing and [b] multiplying is meaning that the bioload on the aquarium is going up. In other words, you have more fish in the tank now than you did X months ago. So it may well be that the filter system that worked back then is overloaded now. Too many fish, too little filtration, and too much food are the key issues.> If all fish are bright happy and making fry - should I stress? <Yes; these are warning signs that conditions are deteriorating. Long term, without correction, things will only get worse.> My oldest black female has always been anti- social, she pretty much lives behind plants and the filter but always comes out to eat or to say hello if I walk up to the tank. <"Saying hello" and being "antisocial" are things humans do, not fish. This fish is likely bullied by the other fish, and the only place she can hide is behind the plants. She's unhappy. Likely because the tank is too small. It's very important to think about animal welfare in terms of how animals work, not people. Much cruelty gets done by people who treat their animals as if they were human beings.> (I used to watch her like crazy for signs of illness - but she never has gotten sick- and she loves people - just hates other fish) <Female Mollies don't "hate" other Mollies, they're a non-territorial, gregarious species. But male Mollies certainly are aggressive, and should only be kept one to a tank unless you have a lot of males in a very big aquarium. Your tank is too small for Mollies, hence social problems. The fault is with your fishkeeping, not the fish.> Babies are also happy, eating and chasing each other Is it futile to expect that I can ever get this stupid strip to stop turning pink??? <Not rocket science. Read the WWM articles on freshwater filtration, water changes.> Thanks so much... Melissa <Cheers, Neale.>

Re: Water quality.... -03/28/08 Neale, <Melissa,> I appreciate your taking time to reply to my email; i had no idea was being cruel by keeping 3 / 2 inch fish a 10 gallon tank, this tank was inherited and i have always been given a inch per gallon rule of thumb. <The "inch per gallon" rule is a hopeless source of confusion. It is completely contextual and depends on various factors. For example: twelve Neons and one adult Oscar are about the same size, 18 inches, but quite obviously the Oscar needs a much larger aquarium. Another example: Bristlenose Plecs and Giant Danios are about the same size in length, around 4-5", but one of them is sluggish and doesn't move much, while the other is hyperactive and needs lots more swimming room. Yet another example: two tanks containing 20 gallons of water, one deep and narrow, the other shallow and broad. Which can hold more fish? The second tank will hold many more fish than the first because the surface area of the aquarium is essential for oxygen and carbon dioxide exchange with the atmosphere. In other words, make your decisions on whether a fish will fit into a given tank by thinking about the needs on the fish rather than simply locking yourself into believing in the rather useless "inch per gallon" rule.> While i realized that this isn't "rocket science" i am fairly new to this hobby and trying to be proactive and to learn to properly care for my fish. <Very good.> There are many who don't bother to research or ask for help, but rather replace dead fish for 3 bucks at PetSmart. <Indeed. But I can't do much to help those people. What I *can* do is give solid advice to those who ask for it. That advice might not be welcome, but it comes from 25 years of fishkeeping and a background as a zoologist.> Sorry to have wasted your time with my problem fishkeeping - <Not wasted my time at all. Happy to help.> Also, i am quite aware of the consequences of animal welfare as i am a licensed veterinary professional -( however i have not had training or experience working with fish ). <Very good. There are some differences between fishkeeping and, say, keeping a dog. One of the key things is that fish don't really adapt their behaviour to the home. A dog builds its social life around its owners. Fish don't; their social lives pretty much get determined around how we arrange the aquarium in terms of space, tankmates, hiding places, etc. If you're keeping Mollies then, what you have is a species that lives in relatively open habitats where the males fight with one another to monopolise access to the more gregarious females. Expecting them to "play nice" in a small aquarium is unrealistic. Its a bit like someone who gets a Border Collie but doesn't want to take it on long walks to use up its energy: the results will be bad!> I spend quite a bit of my time educating owners on the proper care of their pets - i often have to remind myself that not everyone has discussed this very same topic over and over, day after day. I sought your advice because i was concerned; and because you offer your advice as a service - <Service, yes. But remember we don't get paid for this. I answer a dozen messages a day, and that takes a good hour of my time. I do this because I want to and because I can help people look after their animals better. I suspect you are merely reading my direct British English as harshness. Sometimes Americans find British directness and irony difficult to handle. If that's the case here, I apologise. No ill-will was intended. Merely clarity.> And yes; i also realize that fish are not people - i personify their behavior out of affection and in an attempt to explain it to someone who cannot see it- weather or not my molly actually saying hello is not actually related to the quality of care i provide. It just pleases me to see her get excited. <Ah, but you misunderstand me. I talk to my fish all the time, and get excited when they respond to me in some nice sort of way, like becoming tame enough to hand feed. I have nothing against people appreciating fish as pets. Quite the reverse. But it *is* important not to let that slip into fuzzy thinking about their behaviour that hides latent problems. So when someone says that their fish is "shy", does that mean it really is a shy animal, or is so bullied it won't leave its hiding place?> The same way it pleases you to be so knowledgeable. <Ouch.> Next time i will be sure to seek the advice of someone who enjoys giving it with tact. <There are certainly plenty of other places to get advice. The quality of that advice is variable though. Here at WWM you get people who are at the top of their game, and many of us do this for a living, as I do, writing books and magazines. For what it's worth, I think you're overreacting here. Looking over my response nothing there seems particularly rude or tactless. Direct, yes. Remember: my first priority is the fish. Making you feel better is secondary. If I somehow made you feel unhappy, then I apologise. But rather than dwelling on that, look over the advice I gave. The tank is too small for this sort of fish. Water quality is poor, and long term that will make the fish sick. At least one fish is apparently being bullied. Put the animals, not your feelings, first. Their lives are in your hands, and the most I can do is tell you what needs fixing in my (yes) expert opinion.> I will also be sure to let others know just where they can go to find helpful, objective advice. <Please feel free to do so. We already receive literally hundreds of queries every week, and all those people get top-notch advice from experienced and professional fishkeepers. Very few of those people seem to be unhappy, and I get more than enough "thank you" notes and follow-ups to tell me I'm doing a good job.> Cheers, Melissa <Cheers, Neale> - I have to wonder if this is the first time someone has taken issue with one of your responses?? <Nope.>

Mollies, sys. period I have neon tetra, black widow tetra, swordtails, guppies, mollies, clown loach, Corydoras and danios the female Sailfin molly has just recently started looking ill as if she has shimmy but she also has white on her fins they look like they are sticky, I have had mollies years ago with no problems in ordinary tropical freshwater setup I do not know what to do. I have given her 2 salt baths up to now she seemed better only for a while. Any help appreciated, apologies for being so long worried as I also have guppy fry I have purchased another tank for my pregnant fish. Elizabeth <Please see here for more on Mollies: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm The bottom line is that Mollies aren't compatible with standard community fish. At the very least they need very hard, high pH conditions with near-zero nitrate. Nine times out of ten they need slightly saline water as well. So fine with salt-tolerant fish (e.g., Guppies, rainbowfish, glassfish) but otherwise not reliable community fish. Cheers, Neale.>

Keeping/Breeding Saltwater Mollies 3/19/08 Hello, <Hi> I have learnt many things on this site and it has all been helpful. I read the article on mollies and saltwater and how to acclimate them although I was just wondering if it is much more difficult in the marine tank. <Not really, standard SW maintenance and they should be fine.> I used to have mollies years ago but got away from the tropical fish and bought cichlids. I have now got a 55 gallon cichlid tank, a 90 gallon saltwater tank, and a 25 gallon saltwater tank. Once I noticed (on this site) that mollies can do quite well in saltwater I was shocked at first since I had always seen them as freshwater only fish. <Actually in my experience mollies do worst in straight freshwater, I have had much better luck keeping them in brackish and marine conditions.> Sorry for the rambling but here's my question. Will they breed just the same in the marine tank or will the brood numbers be less/more? <Pretty much the same, amazing little creatures.> Thank you in advance. Mike <Welcome> <Chris>

Re: Keeping/Breeding saltwater mollies 3/19/08 Hi, thanks for the very quick response and good to know they are easier in marine tanks. <Welcome> I think I am going to go with the 25gallon tank I have setup which currently but only for today has a damsel in it. I had to remove him/her from my 40gallon tank since he killed my yellow tang and a couple others and yes bad move anyways on having a tang in a 40gallon). <Yes> I have been told my setup is not the best. I have upgraded from the 40gallon to a 90gallon and have 1, going to be 2 fire clowns, 1 sally light foot crab, only one black turbo snail, going to get more sometime, 1 jewel puffer, <Not familiar with this common name but assume it will eventually eat any snails or crabs you have in the tank.> 1 neon blue velvet damsel and a couple green star polyps. The biggest fish in the tank is the puffer which is about 2.5 inches long. The last time I did try mollies in saltwater they only lived for about a day then died, did I most likely acclimate them too quickly? <Most likely, although they are generally pretty tough.> And what type of molly thrives best in marine water; reg. black molly or will any type work? <Any type of true molly should be ok, but be aware that you may see platies or even swordtails labeled as mollies, and these are strictly freshwater fish.> Thanks again, Mike <Welcome> <Chris>

Molly tank 3/7/08 Hello, First off I just wanted to say I just received Neale's book "Brackish Water Fishes" and what a great wealth of information it has! I found most if not all my questions answered or at the very least a fine place to start to research more. <Thanks! Glad you enjoy!> I wrote earlier about my slightly brackish molly tank and since then it has been cycled thoroughly and properly, had a few births and overall no issues. I had been interested in growing more plants so I did gradually lower the SG from 1.005 to about 1.003-1.002 and I have had great success with Val.s, Anubias, sags and even wisteria and Anacharis all in about a months time. <Very good.> I have 8 of the 2 inch variety of Mollies in a 20 long, 2 males and 6 females and they seem to have adjusted fine and have had no issues. <Likely yes. Even a *little* salt seems to make a huge difference with Mollies, which is why I consider adding salt to Molly tanks a no-brainer.> My question is on Filtration. I had been running a BioWheel 150 AND a BioWheel 100 together, but it seemed to create way too many micro bubbles (and current) because of the proximity I had to place them and even though I still have good circulation and no gasping fish I was wondering if this was enough filtration based on my stocking levels, my SG and length of my tank (30" long, 12" tall, 12" wide). <Likely fine. The acid test is to use your nitrite test kit; if you get a zero result, then you have at least adequate filtration. In any case, add together the filtration you have, and make sure the turnover is not less than 4 times the volume of the aquarium in turnover per hour.> I do run an air-stone at night when the lights are off since the tank is moderately planted. My fish actually seem to like this better and use more of the tank now to swim and congregate but I want to avoid problems in the future. Any help would be greatly appreciated. <If it works, and the fish are healthy -- then that's all you need to know. Keep an eye on water quality as your fish multiply of course, and clean/replace filter media as required to keep things working properly.> Oh sorry, one other question. In using sand as a substrate ( I have Aragonite sand mixed with a bit of gravel, maybe 2lbs to the 15 lbs of sand) what is the proper way to vacuum? Is there any need to go into the sand or just hover the siphon over it and stir it up a bit with my finger or a piece of tubing? <Either; plants oxygenated the sand with their roots, so you don't get anaerobic decay in planted tanks. I'd recommend simply scooting over the sand with the siphon and not doing too much stirring, since that would damage the roots. Feel free to add some Malayan livebearing snails if you want; they do a great job of cleaning sand. Shrimps would work in this tank nicely too, certainly Amano shrimps, and likely Cherry shrimps too (the latter seem to do well in my very low end planted brackish water tank with Limia and gobies). Cheers, Neale.>

Molly issues. Hlth., env. 3/3/08 Hello, and I hope you can help. I've searched through the archives and I have a problem that seems to be a combination of things. I had two mollies in my ~7 gallon tank. <Too small... Mollies are hypersensitive to fluctuating/poor water quality, and simply don't do well in small tanks. 20-gallons is the minimum. To be honest, a 7-gallon tank isn't much good for anything; even an expert fishkeeper will have trouble keeping stuff alive in there.> The first molly has unfortunately passed, probably due to my ignorance (the pet store did not inform me of the semi-intense care that mollies require upon my purchase). <Not sure "intense" is the word; but yes, Mollies have very specific needs. Ignore them, and they die. End of story. Do see here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Unless you are an expert fishkeeper (and forgive me if you are) then I would recommend, nay, insist, you keep Mollies in brackish water. They are altogether hardier under such conditions.> I am attempting to save the remaining molly, but she is showing some of the same symptoms as the one that perished. They are both Dalmatian mollies. I did not have a heater in my tank, so I think the first molly may have gone into shock which may have depressed his immune system. <Why no heater? Mollies are tropical fish, and in fact like water a bit on the warm side; 26-28 C seems to be the optimum, and certainly never less than 25 C.> The second molly is now hanging out at the bottom of the tank. She seems hungry, but when she attempts to eat the flakes that I give her it looks like she is spitting them back out, then hungrily goes to the next flake only to spit it out again. <Fish will spit out food if they are not hungry or don't like it. Try something else. Frozen bloodworms (not freeze dried) and algae-based flake foods are the staples for these and indeed most other Poecilia. Generic flake foods aren't really what they want/need.> I noticed my first molly doing the same thing, but she never did until now. When she has evacuations (she must be eating something), they are generally long and occasionally have a long trail of transparent mucous-like substance trailing them. <Evacuations? Is that a euphemism for defecation? If what we're talking about is the faeces are long, stringy and pale, then that doesn't necessarily mean disaster but it can indicate lack of overall health, constipation, etc. Lots of people forget Mollies are herbivores and feed them standard tropical flake food. This is not good for them. They need algae, algae and more algae!> I tried giving her spinach yesterday because I read on your site that the issue may be constipation, but she didn't touch it. I don't notice any growth on her gills, but she is much more lethargic than she used to be. I've only had her for about two weeks. <Sounds doomed to me... Unless you're prepared to raise your game here the fish isn't going to live long.> I put a pH-balancing tablet and an ammonia-eliminating tablet into the water. <What on Earth are these items? OK, let's make this crystal clear: there is no such thing as an ammonia-removing tablet. If they sold you this in the store, they obviously see you as the perfect customer, i.e., you'll buy anything. What makes ammonia go away is the biological filter, which you (I hope) have in place by cycling the aquarium for 4-6 weeks before adding any fish. Or else you took live media from another tank. But please tell me what you didn't do is stick two Mollies into a brand new aquarium. If you did, you may as well have stuck your fish on the barbecue for all the chance they'll have of surviving. Now, the "pH tablet" is something you should stop playing with. At this stage in your fishkeeping career you should not even be thinking about changing the pH or hardness of the water. You first test the pH and hardness of your tap water, and then you buy fish that will thrive in it. If you have soft water, but want to keep livebearers, then buy some MARINE salt mix, and add a certain amount (I'd recommend 6-9 grammes per litre) into each bucket of water added to the tank. Mollies MUST have hard water, and if you water is soft, adding marine salt mix will raise that hardness as well as the salinity in a safe, convenient, and inexpensive way.> I now have a heater and ensure that the temperature stays around 80 degrees Fahrenheit. <Thank the Gods!> I am trying to grow live plants in the tank. She hovers over the bottom of the tank and her gills are opening fairly rapidly. <Dying. This is called "the Shimmies" and indicates when Mollies are being kept chronically badly.> Also, I noticed that after a while the rocks in the water start to emit a blue dye. <No idea what this is. But GET THOSE DAMN ROCKS OUT NOW! Nothing you put in a fish tank should do this. ONLY buy aquarium-safe rocks.> I have cleaned out the rocks thinking that was the problem, but she is still showing the same symptoms. <Doubt the rocks are the key thing here, to be honest.> Could the problem be an internal parasite? <Nope; bad fishkeeping.> I was also wondering if she might be pregnant, but I don't know the signs of pregnancy. <May well be, but this isn't what's causing the problems.> Any advice you could give would be helpful! <Read a book. Please. The only way you could be keeping this fish worse is by forgetting to put water in the tank. You are doing everything wrong. I really, REALLY want you to enjoy this hobby, and even more want that poor little fish to survive. But you MUST raise your game. Short term: stop feeding the fish until you buy a NITRITE test kit and learn how to use it. Do 50% water changes daily for as long as you detect nitrite in the water. Add marine salt, not less than 3 g/l. Don't use "tonic salt" or "aquarium salt" or anything like that. You want the stuff marine fishkeepers use because ONLY that will raise the carbonate hardness along with the salinity. These perform together to make Mollies happy. Once you've done that, start saving your pennies for a bigger tank; not less than 20 gallons.> Thanks, Cara <Good luck, Neale.>

Mollienesia: health, environment 2/19/08 Hi there, I just found your website and it's amazing. Have bookmarked it for future reference :) Just have a small question. I got a new Dalmatian molly today as a present for my newly cycled tank. I first found you whilst looking up his odd behaviour. He's been swimming rather strangely -tilted to one side when swimming straight, when stationary his head will drift slowly upwards and he'll stay like that for a while before swimming backwards (still with head vertical) and rubbing himself against other fish. At first I thought it might just be a quirk, but I checked out nitrite etc just to be sure. They're all fine. I wanted to be sure it wasn't a swim bladder infection or anything, so I started watching him a bit more closely. I noticed he's got a small injury just above his mouth on one side, and it's this side that he rubs against other fish. I'm quite worried he might have an infection but am not sure how to tell, and if he does whether I should quarantine him or not. The injury also looks very clean, so there is a chance that it's slightly older and healing and it's this that's caused his behavioural change. Please help! A very worried Su xx <The first thing to ask is whether this Molly is being kept in freshwater or brackish. While these fish *can* be kept in hard, alkaline freshwater conditions, under aquarium conditions they are much easier to maintain in brackish water conditions. Around 10% to 25% seawater salinity (around SG 1.002-1.005) is ample. You need to be using marine salt mix, not tonic salt, when keeping Mollies because it is the extra carbonate hardness as well as the salinity that helps. De see here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Mollies aren't community fish and shouldn't be sold/bought as such. They need very specific conditions to work well. I have no idea what is precisely wrong with your Molly, but these "mystery diseases" are all too common when Mollies are kept in freshwater tanks and in environments with nitrate above 20 mg/l. At least one problem, known as the "Shimmies", manifests itself as water-treading behaviour, when the fish seems to rock from side to side. This could very easily be mistaken for a swim bladder infection. The Shimmies is almost entirely observed when Mollies are kept too cold, in water without sufficient carbonate hardness, and/or there's a high concentration of nitrate. The addition of sea salt to the aquarium is one treatment that helps, provided the fish isn't too far gone. Cheers, Neale.>

Black molly/general help for new fish keeper! -- 02/07/08 Hi. <Hail.> I got my first tank for Christmas from my girlfriend as I have wanted to keep tropical fish for some time. On the advice of the store my girlfriend bought a small tank as the man in shop said it would be easier to start with a small tank, it is a Aqua One UFO 350 I think it is between 30/35 Litres. <Garbage advice... a tank this small is very difficult to look after. As a broad bit of advice, beginners should be looking at tanks around 75-90 litres (20-25 gallons). It's just so much easier to keep good water quality and choose a nice variety of fish.> Again after taking advice from aquatic centre we were told Molly's would be a good fish as My first fish so I now have two black mollies and one orange Molly. <A bad, bad choice I'm afraid. Mollies are terrible fish for beginners, and too big for this aquarium anyway. Please do understand: your first purchase should always be a book, not a fish. Store advice is sometimes good, but sometimes terrible.> However eager to be responsible and make sure my fish are happy I have done as much reading on keeping fish as possible...however this has posed more questions than answers as everybody has different advice. I am still feeding my fish every other day as advised when I bought them about four weeks ago...yet other resources recommend feeding more than once a day. <It's contextual. With most small fish, several small meals per day is the ideal, and closest to what they'd do in the wild. Fish have (usually) short intestines, and can't slowly digest a big meal in the way we can. On the other hand, in a new aquarium, you don't have the filter bacteria to cope with the ammonia the fish produce as a waste product of metabolism. To deal with this, you scale back feeding so that the fish are producing the minimum of waste and moreover you aren't overfeeding them, any excess food simply rotting and making ammonia that way. Hence good advice is feed sparingly when the tank is "new" (which can be anything up to 6 weeks in the case of a tropical tank). Once the tank is mature, you alter the feeding to best suit whatever fish you have.> I am also starting to think that recommending such a small tank will prove more difficult rather than easier as I am worried my fish do not have sufficient space and worried about over stocking. <Correct.> My water quality is fine and I am changing 25% of water every 2 weeks...yet some resources recommend weekly water changes others say once a month! <Back in the pre-history of the hobby (i.e., prior to the 1980s) aquarists avoided doing water changes as much as possible. The idea was that "old" water was in some way biologically active and better for the fish. "New" water undid this good, so you tried your best to avoid adding any. Hence, 25% water changes per month were considered a good thing. To stop the water going yellow and smelly, you'd put carbon in the filter to remove dissolved organic materials that accumulated in it over time. Nowadays the value of new water is appreciated, especially now we have reliable dechlorinators and other treatments that make new water perfect for aquarium fish. As a result, aquarists are now advised to change at least 25% per week, and ideally more than that. You really can't do too many water changes, *providing* the water chemistry and temperature are kept consistent. Since you're changing lots of water, carbon is now redundant (in freshwater systems, anyway).> I have also read that Molly's prefer brackish water and that I should add salt to my freshwater aquarium is this correct? <This is a hot topic among aquarists, but the basics are these: in aquaria with excellent water quality and a hard, alkaline water chemistry, Mollies can sometimes do well without salt. But they always do better with salt, and in brackish water you have much less change of Mollies getting sick than otherwise. For inexperienced fishkeepers at least, the addition of salt is definitely a good idea.> ...Anyway to my biggest concern one of my black Molly's has recently taken to spending most of its time right at the bottom of the tank hiding amongst plants. It does not appear to have anything physically wrong with it and every now and again it will swim and does come up to feed but this is very rarely. I have noticed the other black molly acting aggressive towards it and "nipping" at it and chasing it around the tank. The other two Molly's appear fine and happy. <Try adding salt and see what happens. Mollies sometimes develop a problem called "the Shimmies" which is named after the dance of that name, and refers to the fact the fish seem to be treading water, sometimes rocking from side to side. It's a neurological disorder of some sort. In any case, common salt acts by detoxifying nitrite and nitrate, two chemicals that make Mollies sick. You need about 6 grammes per litre for best results (I believe one teaspoon is 6 grammes, but you can check that easily enough with some kitchen scales). Stir the salt into the new water before adding it to the aquarium; don't add the salt directly to the tank! Raise the salinity in stages, e.g., do a series of 25% water changes across a few days, taking out old water and replacing it with water that has salt added. This will keep the filter bacteria happy.> I really want to get things right so any help on any/all of the above issues would be greatly appreciated. <Do have a read of this article: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Hope it helps! Neale.>

Molly Tank 1/27/08 Hi all, <Ave,> I do have a question or two about my brackish molly Tank. I was having a lot of problems trying to keep my mollies in FW so I decided to go low salinity (SG 1.005-1.008) brackish tank and keep mollies that I had (3) and eventually a few Bumblebee Gobies. <Very good.> The tank is 14 gallons with aragonite sand, ph 8.0- 8.1, Temp 82F. The tank is not cycled. It started with 3 mollies. I did acclimate them, but I think I might have taken some bad advice and did it a bit faster than would be desired, like over several hours instead of days. Both females had fry in the new brackish water, about 18 total. <Mollies can be acclimated between marine and fresh in less than an hour, so unlikely a problem here.> The problem is this: first off, there was flashing, even the new-borns, occasionally shimmies, which I had in the freshwater environment which is what eventually led me to going brackish. Later in the week twitchy behavior for my male (like a nervous twitch and then get all tense) and sometimes 1 or 2 of them would skip across the top flapping tails. <Do check water quality. Essentially, the problem with Mollies seems to be a hypersensitivity to dissolved metabolites. Not just ammonia and nitrite, but also nitrate. If you suddenly raise the salinity in a freshwater aquarium, you are placing a stress on the filter bacteria. As a rule, you can go up to about SG 1.005 without any problems, but once you go above that, the filter bacteria seem to die back or at least stop working properly. So the usual process when creating a brackish water tank from a freshwater one is to raise the salinity in stages. I'd recommend adding SG 1.005 water to the aquarium each week, replacing about 20-25% of the water in the tank. After about a month the specific gravity will be 1.005 or thereabouts. Leave things be for a couple of months. For Mollies and Bumblebee Gobies, this salinity is more than adequate for long term health. But if you did need to raise the salinity further, do it in small increments over the succeeding months, checking the ammonia and/or nitrite all the time. It's much better to choose a lower salinity without ammonia than to go the whole hog to a high salinity but have ammonia in the water because the bacteria are unhappy.> And then one fish in particular would stay at the top and gulp for a very long time. I originally had a BIO-wheel 100, which I swapped out for a BIO-wheel 150 and a Whisper 10 air-pump and air-stone. Ammonia was reading at about .25 so I did a 10% water change, lowered the temp a tad to about 80F and the water line to get more surface agitation. <Ah, almost certainly this was the issue. The filter is stressed from you taking the salinity too high, too quickly. Give it four to six weeks to re-mature, putting the minimum food into the tank and performing regular water changes. Lower the salinity to SG 1.005 to economise on salt usage, but step up the water changes in the short term at least to keep the ammonia/nitrite levels low.> This morning I decided to go out and get the babies their own tank thinking perhaps the bioload was not too good and maybe the oxygen not so good either, especially with the temp and SG. I am very new to brackish so a lot of this is new to me. <Please do read the articles on the topic here at WWM. Or my book!> Anyway, Ammonia is 0 again or at least at the lowest color on the test, but my Male molly still has the twitches and tenses up and occasionally flashes off the filter inlet tube...this is like once today though, not like once every 5 minutes like before. <Getting better, I guess...> One of the females still is piping occasionally, but not for prolonged visits, like just up, gulp gulp, down. <Mollies are distinct among the livebearers in being able to use atmospheric oxygen when the situation is bad. They gulp water from the air/water interface across the gills, extracting the dissolved oxygen. In the wild this allows them to survive in swampy environments better than other livebearers. It's a "normal" behaviour, albeit one that implies less than perfect water quality.> Shimmies at least visibly gone. SO I guess what I am asking is do you think this is a gill infestation/infection or do you think the water quality just got really bad really quick? <The latter.> Also will the fish recover if water quality, maintenance and stocking are done properly in the future? <Yes; in brackish water Mollies tend to be rather robust and durable.> Any help would be greatly appreciated. Keith <Good luck, Neale.>

Re: Molly Tank 1/26/08 Thank you for the quick reply. <Happy to help.> I have started daily water changes and am monitoring the ammonia and salinity to keep them under control. <OK.> One more question for maintenance, what test kits and water conditioners can I use...meaning, what freshwater stuff is ok to use and what must be marine? <Water conditioner is fine for freshwater/brackish/marine uses. Water chemistry test kits are normally fine in FW/BW/M though some are not; check the package. Water quality test kits are usually fine too. Medications are often fine in both, though some are not; again, check the package you have.> Currently I have freshwater Nitrite and Ph tests and an ammonia test kit that is for both SW and FW. What about FW phosphate removers, dechlor, etc or is that not an issue because the water is treated before going into the aquarium? <The nitrite test kit should be fine in brackish, and likely so too will the pH test. The issue with pH test kits is that marine aquarists want ones that are accurate across the high range (between 8 and 9) whereas freshwater aquarists want ones to use between 6 and 8. So the two types of test kits are tweaked to work best depending on what sort of tank you have. So long as your test kit measures 7.5-8.5, you're OK using it in brackish.> I am guessing low salinity like .005 is probably closer to FW than Marine, but how much of a variance does the salt add in accuracy of FW tests and possible conditioners being toxic in a Brackish tank? <As you say, not a huge impact. For the time being stick with what you have. As and when they run out or expire, switch to ones suitable for both FW and Marine, and these'll have you covered. Cheers, Neale.>

Re: Molly Tank 1/29/08 Neale, <Keith,> Thank you! Everything is settling in and the fish seem very happy/normal and less irritated. <Very good.> One last thing please: At what level does ammonia "start" to initiate the cycle and at what level should a water change be done? <Difficult to say, but in practise you never need to allow the ammonia concentration in the aquarium to reach measurable levels if there are fish in the tank. When people are cycling tanks *without* fish they can let the ammonia level go as high has 0.5-1 mg/l safely enough, but there's no real advantage given that the growth rate of the filter bacteria is limited by oxygen as much as ammonia concentration. Hence in practise when you are cycling tanks with fishes in them, you do your level best to keep the ammonia (and nitrite) as low as possible. The bacteria will get enough of both even so. Water changes during the cycling phase should be as often as possible, but as a baseline I'd suggest 25% daily for the first week or two, and after than about the same amount every 2-3 days. After week 3 or 4 you should find ammonia stays close to (or at) zero, and nitrite under 0.5 mg/l, and you can get away with two 25% water changes per week. After week 4 and certainly by week 6, the cycle should be finished and you can switch to 25-50% water changes weekly. But these are estimates: your own "mileage may vary" and you need to follow your nitrite test kit results rather than the theory.> I just saw that your book ( Brackish-Water Fishes: An Aquarist's Guide to Identification, Care & Husbandry) is available on Amazon, ordering on payday. Again, Thank you for the invaluable help. <Hope you enjoy the book!> Keith <Cheers, Neale.>

Possible over crowding of mollies 1/19/08 Hi crew! I have a couple of issues that I need help with. First off, I have to mollies and I am not sure what species of molly they are. The female one is a light golden color with a white underside and white fins and tail. The male is orange with little white spots on his top side and dorsal fin. He also has a white underside, fins, and tail. Can you tell me what breed they are? <Mmm, not from this description, no. There are meristics differences twixt species of Mollienesia... see Fishbase.org re> Laila, the female, has been showing signs of pregnancy for over a month. As soon as I noticed she was pregnant, I put her in a pregnancy net. <Mmm... best not to move mollies much...> Weeks have past and she is still plump with fry. I took her out of the net today after cleaning my 10 gallon tank. I decided to take her out because it had algal growth all over it. Also, I noticed the male fish was losing his appetite and hanging out around her net, which I thought was due to loneliness. <Interesting observation/conclusion> Last time she was pregnant, I didn't put her in a net or quarantine her in any way. I was caught off guard when I saw the fry swimming around on the bottom of the tank. The thought of them reproducing never crossed my mind. After a couple of days in the tank, I noticed that the fry had disappeared. I am new to raising fish and can use all the help I can get. Should I put Laila back in the pregnancy net? <Possibly> I was reading a few FAQs on your site about mollies needing a 1 to 4 ratio 1 male: 4 females. Like I said above, I have a ten gallon tank. I'm not sure it will be able to support 5 mollies with their reproduction rate. <I agree... This is not much room> Should I get a better tank and add 3 other females? <A bigger tank is a very good idea... and another female or two as well> If so, where should I get the tank and fish? What type of tank should I get? Do I have to get the same breed of fish? --Alia Abul-Haj <Please read here: http://wetwebmedia.com/FWSubWebIndex/mollies.htm and the linked files above. Bob Fenner>

Mollies... sys. 12/30/07 Hello I have a couple questions for you. How big of a tank should I get to store 7 mollies? All of the mollies had the same mother and father, can they produce fry? I have done a lot of research on Dalmatian mollies and when they say something about the anal fin and how you tell if it's a male or female. Well could you send me a picture of a male, female and a pregnant female so I know how they look so I can look out for things like that? I would appreciate any advice you can give me. <Greetings. Some Mollies are bigger than others. The smallest varieties, like Black Mollies, typically reach no more than 7 cm/3" in size. At the other extreme, Mexican Giant Sailfins get to over 15 cm/6" in length. Dalmatian Mollies are somewhere between the two, around 10 cm/4". As well as their size, Mollies have two other issues to consider: they are [a] very active and [b] the males are very aggressive towards one another and sometimes towards the females as well. So you want to be generous when allotting space, so they can swim about happily. Finally, Mollies are highly sensitive to poor water quality, especially nitrate. A bigger tank makes it easier to maintain good water quality. Without a doubt, the bigger the better for Mollies! I'd highly recommend a tank not less than 90 cm/3' in length. Sexing Mollies is easy: the males have long, narrow anal fins that look a bit like bent sticks. Females have regular, triangle-shaped anal fins. You cannot tell if a female is pregnant by looking at it. Some people do breed from brother and sister fish, but it isn't a good idea for all the obvious reasons. Inbreeding will cause problems such as deformed fry and low fertility. So bring in new genes if you want to breed healthy Mollies by buying males and females from different batches of fish. For more, be sure and read this: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Cheers, Neale.>

Molly - need your expert opinion, sys., hlth. 12/5/07 Hi, I love your site. I am new to all this - I have read and read and read on google and all kinds of sites about my specific questions but I am getting mixed information and partial answers, so I thought I would get your opinion on it. <Hmm... Google is efficient at finding stuff, but remember that the Internet is a mix of 50% gold and 50% garbage. If you're new to fishkeeping, you will be MUCH better off buying or borrowing a decent aquarium book, of which there are many. These will be edited and written to a higher standard than most of the stuff on the Internet.> I have a 40 gallon hex tank with a side filter / carbon filter that goes inside etc/ I have 6 small red eye tetra, 4 mollies and a female (very sweet beta) <OK, start by chucking out the carbon. Waste of money and space. Replace with some filter wool or ceramic noodles. Carbon serves no useful purpose in most freshwater aquaria. Biological filter media is always useful. Tetras and Mollies are not good tankmates; Mollies almost always do better in salty water than freshwater, whereas Tetras (for the most part) don't tolerate salt at all.> First of all I know I have totally stressed out my black molly because of moving her too much. <Oh?> Two of my females have wound up pregnant, I don't want the other fish to eat the fry. I bought one of those breeders where the mothers are up top and the babies end up going thru a slot on the bottom so they are protected. <Never, ever put a Molly in a breeding trap. She will hate you with the heat of nova. Breeding traps are really something that sounds a better idea than it actually is. Mollies are too big for them, and really so are most other livebearers. Instead, stock the tank with floating plants. Hornwort is idea. Check the plants once or twice a day, and then remove fry to a breeding trap or better still another tank for growing on.> First of all, one of them has been huge for about 4 weeks and for 4 weeks I have been saying, any day now! No fry yet and I have no clue when she is going to have them. Any signs I can watch for so I can get them out quickly with a net ? Do you have any pictures so I can see how big they are supposed to get. Maybe there are not really any signs? <One problem with Mollies is that in freshwater they often get sick, and oedema (dropsy) can look for all the world like pregnancy. Another issue is some varieties have been deliberately bred to be rounded, so it isn't obvious if they are pregnant or not. Finally, many fish will eat the fry at once. Sometimes even the mothers! So the babies can literally have a lifespan of minutes, too short a time for you to observe them.> I put her in the breeder for a about a day and noticed she seemed stressed and I felt bad because it was so small. I know mollies require lots of space to be happy. I have found very different opinions on this subject matter. <I can't think who in their right mind would be opining that Mollies are happy in breeding traps or don't need space. As I said, 50% of the Internet is garbage.> I took her out of the breeder and put her back in the tank with the others for about a week. Much better!. Then I decided to put her in my daughters tank which is bigger than the breeder but still small (it's like 2 gallon). (I don't have the extra $100 or so to set-up a new tank right now being so close to Christmas) <Floating plants... floating plants... cheap, effective...> After her being in the 2 gallon for a couple of weeks, and still no fry, I moved her back into main tank again since she seemed stressed in there. I put some plastic floating plants at the top and there are lots of holes in the ornament that all the fish can get into. <A two-gallon tank is really not going to work. For one thing the Molly will be incredibly stressed. Miscarriages under such conditions are common. Even if any babies were born, she might eat them because there's really no space for the baby fish to swim away.> Those tetras seem kind of aggressive and chase the other fish and I am worried that they will eat the fry - will they ? <As sure as God made little green apples...> Should I get rid of those ? I can find someone on craigslist to take them probably. <Yep. If you want to keep Mollies -- seriously -- and get babies, then your life will be 100 times easier if the Mollies have a spacious tank with some salt (~3-6 grammes per litre) added to the water and lots of floating plants. The Tetras are merely adding a complication.> Thanks for the information. Wendy <We do have a nice detailed article on Mollies, here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm Have a read, follow the links to related articles, and good luck! Neale.>

Re: Molly - need your expert opinion12/5/07 Thank you, thank you. I appreciate your time and your very valued opinions. I let the Molly out of the breeding trap and I am going to find another home for the tetras ASAP. The word "trap" should be an indicator huh ? :-) Your awesome. Wendy <Cool. Glad we can help. Mollies are among my favourite fish, and when cared for properly EASILY fill a tank with colour and entertainment-value all by themselves. That's why I recommend people keep them alone so they don't have to make compromises to allow for their tankmates. Give the Mollies 100% of what they want, and they'll repay you handsomely! Colour, activity, sex, and babies. What more could you ask for! Cheers, Neale.>

Aquarium Questions, FW lvstk. comp., salt use -- 10/28/07 hello, i might start a 55 gallon tank soon and i was wondering if my conditions were right for the fish i want to include below. Also, if they can all get along and if its a good amount for the tank. Please also recommend some tetras for me that get along well with angels and if Cory cats or upside down cats are better. <Mmm, Hyphessobrycons in a group are some faves... And I would go with Corydoras over the Synodontis here> The tank will have 1 tablespoon of salt per 5 gallons, can they deal with it? <I would not add the salt... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/saltusefaqs.htm> Thank You! Tank Conditions: Size: 55 gallons Temp: 74-82 F PH.5.8-6.5 Current Inhabitants in my 10 gallon: 3 platys (might soon be 5 if babies live), 2 balloon belly mollies Salinity Level: 1 tablespoon of aquarium salt for every 5 gallons <Okay here, but not for Tetras, Angels...> Fish I want to add: Tetras-8 Platy-3 or 1 if the 2 babies live Balloon mollies-3 <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm> Angelfish- 5 Upside-down catfish-6 'or' Cory cats-6 Blue/gold gourami-2 Fish in total: 8 tetras 6 platys 5 balloon mollies 5 angelfish 6 upside down cats or Cory cats 2 blue/gold gouramis <Bob Fenner>

Re: Aquarium Questions... salt 10/29/07 thank you for all your help! <Welcome> I was going to add salt because I thought that it would prevent ich. I guess its only good for treating it. <And only with certain livestock/species and settings. BobF>

Re: re: Aquarium Questions... reading, comprehension 10/29/07 So basically mollies wont do good and get diseases in the 55 gallon because I wont add salt? Thanks. <Something like this. Welcome. RMF>

Re: Aquarium Questions... still not reading re Mollies... salt... fixing English... 10/29/07 im sorry if I am bothering you guys a lot but im still pretty much a beginner so I need to know different things so there might be more questions later. Well, I still want to put my mollies in the tank. Do you think 1 tablespoon of salt per 10 gallons is okay for the fish and help prevent disease? I don't want my mollies getting sick so easily since they thrive with a little salt in the water. this is the number of the fish I plan on having in the tank: 8 tetras 6 platys 5 balloon mollies 5 angelfish 6 Cory cats 2 blue/gold Gouramis can u recommend some tetras for me that wont get eaten by the angels and wont nip fins? Thank you again! <Please understand this: Mollies are not good community fish. At the very least, they require hard (18+ degrees dH) water with high carbonate hardness (10+ degrees KH). Such water will have a very high pH (at least 7.5, and likely 8.0 upwards). Mollies also want water that has zero ammonia, zero nitrite, and as close to zero nitrate as is practical. The addition of salt isn't 100% essential, but it is something (in my experience/opinion, based on MANY years of keeping fish and discussing with other hobbyists) that makes keeping Mollies substantially easier. What the marine salt mix (not tonic salt) does is raise the hardness and pH and also reduces the toxicity of the nitrate. This latter effect is probably the critical one. By all means keep Mollies with salt-tolerant fish: Guppies, Swordtails, Hoplosternum littorale, Hypostomus plecostomus, horseface loaches, Kribensis, Bumblebee gobies, Knight gobies, glassfish etc. Add marine salt mix at around 3-6 grammes per litre to the tank and your Mollies and your salt-tolerant fish will all thrive. Mollies under such conditions are robust and more colourful than otherwise. But don't both trying to keep Mollies in a generic community tank. Read over the Molly FAQs here at WWM, or really any other fish keeping forum -- you will see dozens and dozens of messages from people with Mollies plagued with Finrot, fungus, Mouth Fungus and "the Shimmies". Adding salt for the benefit of your Mollies will only stress all the other fish, so you're taking from Peter to give to Paul -- there's no net benefit! Choosing tetras to keep with Angels generally isn't difficult. Good choices including Bleeding Heart tetras, Lemon tetras, Emperor tetras, X-ray tetras, Head-and-tail light Tetras and Diamond Tetras. African tetras can be good, too; things like Congo Tetras. Avoid the small, reddish ones (Serpae tetras, Flame tetras, etc.) and the bite-size ones like Neons, Cardinals and Glowlights. Black Widow tetras (also known as Petticoat Tetras) are fin-nippers too. Avoid. Cheers, Neale>

Mollies & Salt 10/16/07 Hello! I have a 29g established freshwater tank with a variety of Mollies - Balloon Belly, Sailfin, etc. I currently keep 1 tablespoon of salt per 5g in the tank. I would like to add a Bristlenose pleco to the tank but from what I've read they don't really like the salt. Would removing the salt - by not replacing during water changes - adversely affect the Mollies? -Chip <Hello Chip. This is a tricky question to answer. In theory, you don't need salty water to keep Mollies. So long as the carbonate hardness is high (10 degrees KH upwards); the general hardness is very high (20 degrees dH upwards); the pH is around 8.0; zero ammonia and nitrite; and nitrate less than 10 mg/l, you should have the water chemistry Mollies enjoy. An Ancistrus sp. catfish would also do well under such conditions. However, if you take you eye off the ball and any of those environmental parameters slips, for example the nitrates rise above 10 mg/l, then your Mollies will become significantly more likely to become sick. What salt does is reduce the toxicity of nitrite and nitrate, and this is one of the reasons it helps in Molly tanks. Marine salt mix also raises the carbonate hardness and general hardness providing much more stable water chemistry, which Mollies also need. Finally, marine salt mix or regular aquarium salt mix both increase salinity, and since Mollies are, at least in part, brackish water fish, this helps their overall healthfulness. The bottom line is this: Mollies are very hardy in brackish/marine aquaria, but rather delicate in freshwater aquaria. So what would I recommend? Keep the salt in the Molly aquarium. I'd actually skip the idea of Ancistrus anyway. Ancistrus eat algae, as do Mollies. Much better let the Mollies eat the algae, since it's an important part of a balanced diet. If you want a catfish, opt for one of the salt-tolerant species, such as Hoplosternum littorale. There are also some brackish water loaches, and for your tank, the Horseface Loach (Acantopsis choirorhynchos) would be an excellent choice. It's a good scavenger and basically peaceful. Both these suggestions would be very happy at SG 1.003 if acclimated carefully. Hope this helps, Neale>

Some Molly Issues... 10/12/07 Hi folks - very nice forum, full of good information and eats up a lot of time digesting all the advice! I have some issues with my mollies - firstly I'll run through my setup: 1 Marble Mollie (Female) 1 Traditional Mollie (Female) 1 Traditional Mollie (Male) 1 Silver Sailfin Mollie (Male) 2 Pleco (Suckermouth 2-3" maximum) 60L Tank, 25'C Bogwood x 2, Java moss and some other traditional plants with fine sand ground and Tetra carbon filter. <60 litres is too small for mollies. You'll have problems maintaining the zero nitrate conditions they need, and the sailfin mollies won't grow to full size.> Now onto the issues... The tank completed it's cycle about 3 weeks ago, during which these fish were in a smaller tank. However on re-integration back into this tank, all the Mollies all flick themselves off objects, be it airstone tubing, sand, bogwood or the filter. <Sounds like incipient whitespot (ick). Look for small white spots.> They also speedily swim to the surface and splash their tailfin on the surface, making loud splashes. I've checked closely for Ich, and they all seem clear. <Ah, but whitespot can be on the gills, and in this case you won't see it.> The water has just had a 40% change yesterday (it was going cloudy, so I replaced the filter cartridge and did a thorough syphon of the detritus and food remnants). <Hmm... I don't recommend changing biological filter media unless absolutely essential. What sort of filter media are we talking about here? Obviously, replacing biological filter media re-sets the cycling process to the start. Carbon is redundant, and Zeolite shouldn't be required in a regular, properly maintained aquarium.> Is this anything to worry about? <Odd behaviour should always be observed closely.> Secondly, the Sailfin male is very aggressive towards the other fish, and at least once a week will push the other male (who is actually bigger than the sailfin) in the corner, and generally stress him out. <Completely normal. Male mollies are aggressive. In a 60 litre tank, the dominant male will eventually batter the others, if not to death, then into severe stress.> However, the Sailfin sometimes when hanging in the water will slowly tilt upwards, until it is facing directly upwards. None of the other fish exhibit this behaviour at all. Is this something to be concerned about? <Sailfin mollies have a distinct adaptation to living in low-oxygen waters (such as brackish water ditches in the wild). They orient themselves head-upwards, and suck the surface layer of water in the mouth and across their gills. Most other livebearers don't do this. If your sailfin is doing this repeatedly, check water quality.> I am gradually adding small amounts of marine salt into the water (not too much as I'm aware that the Pleco's won't appreciate it) as I have been doing for 2 days now, in an effort to rectify this issue and the flicking issue, is that futile? <Treat for whitespot/ick using a standard medication of some sort. Quicker and easier. Common Plecos (Pterygoplichthys spp.) are fairly salt tolerant, and with care will do well at SG 1.003. This should be a high enough salinity for your mollies. But long term, I'd swap out the Plecos for a true low-end brackish water catfish, such as Hoplosternum littorale or (the true) Hypostomus plecostomus. These are fine up to SG 1.005. You can of course keep large mollies with brackish/marine cats such as 'Arius' seemanni and Mystus gulio.> Thirdly, I have these 'Hikari Tropical' Algae Wafers, made up of everything (it would be a super food if it was for humans I reckon). I usually drop one in and leave it for the Plecos, however I've noticed that the Mollies eat it too. Further to this, could these wafers be responsible for the water going cloudy? <No, these won't make the water cloudy by themselves. They are of course excellent food for plecs as well as mollies. Both species eat a lot of algae and plant material. Water cloudiness comes from three different things: silt from unwashed gravel, bacterial blooms during the early phase of cycling, and overstocking (and it's associated hazard, overfeeding).> On a separate note, I have a smaller 30L Tank downstairs which has 5 Female Guppies, 2 Male, 3 Neon Tetras and 1 baby Mollie - the Guppies are giving birth this week, but the fry seem quite large - are the fry at any risk of being eaten despite seeming too big for the Guppies? <Some will get eaten, yes. Depends a lot on floating plants. If you have lots of floating plants, most fry should be fine.> I don't know how I would catch them either - they are well hidden in the Java Moss, and they would probably pass through my smallest net's gauze. <I catch fry with small plastic cups, rather than nets. Turkey basters can be used, too.> Thanks for any assistance! MPH P.S. if you could email me the link if you update the FAQs with my Q+A that would be most helpful - if not too busy, a reply would be super too, cheers! <Cheers, Neale>

Re: Some Molly Issues... 10/12/07 Thanks for the fast reply - the filter cartridge I replaced was merely the carbon cartridge in my 'Tetra Aqua Art 60L' tank - the bacteria grow in the other elements of the filter itself, so the Cartridge is alright to replace (or so Tetra proclaim). <Indeed. Carbon can be changed as often as you can afford. Certainly, carbon stops doing its thing after a couple of weeks. But personally I consider carbon useless in the average community tank. Water changes are more effective at removing pollutants, and you can replace the carbon's space with more biological media. Carbon is cheap, sounds technical, and thus gets used by manufacturers to sell (at a high price) what is basically just charcoal.> I note that you said that 60L was too small for Mollies - what is a good size tank for them in this case? <Depends on the mollies. I'd keep Shortfin varieties in something around 90 litres, and Sailfins in something above 150 litres. Sailfin mollies should exceed 10 cm in length, and potentially up to 15 cm depending on the species. They're big fish.> Thanks for any assistance, Matt <Cheers, Neale>

Balloon Molly Question... sys. 9/9/07 Hi, my name is Nick and I was searching for answers about my new fish. <<Hello, Nick. My name's Tom.>> I just got a 10g tank and let it run for 2 days. I checked the water and it was perfect. I even took a sample in to PetSmart and they checked it and said it was perfect. <<Not too much to go wrong, or right (in this context), with two-day-old water, Nick. Conventionally cycling an aquarium takes several weeks, not a couple of days.>> So, I bought a balloon molly, a red swordtail, and a upside-down catfish. I put them in and everything seemed was good for about three days. <<First off, Nick, you have three totally incompatible fish living in a smallish 10-gallon tank. Your Molly is a brackish water fish. The Swordtail is a freshwater fish preferring harder, alkaline conditions and the Catfish prefers softer, acidic conditions. Second, as I've suggested above, you placed these fish in an uncycled aquarium which means that after the three days the ammonia built up to very toxic/deadly levels. (You definitely need to research about cycling an aquarium before doing much else!)>> I noticed that when I was feeding them the molly will eat as much as she could every time and it seemed that the other fish weren't getting any food. <<Not an uncommon problem, Nick. I might have expected a little less of a problem along these lines with the Swordtail but the Catfish is likely to be more shy/retiring so it doesn't surprise me here.>> Now today, which is day 4, she is acting weird. She keeps sniping at the swordtail and is pooping constantly. I watched the molly for about an hour and she pooped 4 times. Each one was about two inches long and she is only an inch long. <<In itself, this isn't a problem. She's the one getting all the food, after all. (What goes in must come out.) 'Sniping' at the Swordtail could be from her new-found habit of getting all the food and defending her 'territory' but is more likely a sign of stress. Mollies are very peaceful fish that aren't aggressive given proper conditions. When stressed, however, you should/can expect just about anything to happen.>> She seems like she is sick or something. Should I be worried? <<'Worried' isn't what's called for here, Nick. You can't acclimate these three fish to conditions each wants in the same tank so you've a decision to make. Your best bet is to take the Molly back to the LFS if possible. The Swordtail and Catfish can be acclimated to neutral water conditions -- pH around 7.0-7.2 -- without too much trouble (assuming your water source from the tap has the same readings). Keeping the Molly in favor of the other two would require that you convert your tank to brackish conditions. Hardly an insurmountable problem but not the option I would recommend for someone new to the hobby.>> I am new to this. This is the first time I have ever owned a fish so I don't know. Thanks for your time if you have any ideas please let me know. <<Along with what I've already suggested, Nick, I'll repeat myself on the topic of learning about cycling your tank. Be prepared to make water changes, and plenty of them, until the nitrogen cycle has completed itself. Detectable levels of ammonia/nitrite are extremely toxic, and potentially deadly, to fish. Finally, for future purposes, research the type of fish that you might be interested in prior to making the purchase. Barely a week (day?) goes by that we don't have someone tell us about buying fish that he/she 'just couldn't pass up' only to find that it was a big mistake. (Sidenote: I'd never recommend purchasing your fish from Petsmart but, should you decide to do this, please educate yourself (for your own 'protection') before walking through the front door. Knowledgeable people could have made you aware of what I've shared with you before this ever turned into the issue it's become. Make it YOUR responsibility to know the facts.)>> Thanks again. -Nick <<Good luck, Nick. If you have any questions, you know where you can find me. Tom>>

Update on My Molly Tank 8/2/07 Hi Neale, <Hello Kathy,> First of all, thank you for all your advice! I have managed to lower PH and hardness a little bit by using tap water mixed with RO/DI water. (The ratio I used is 2:1) Tap water is at least twice as much as RO water. <Sounds fine; but remember, the ratio doesn't matter, it's the final set of water chemistry conditions you end up with that are important. But this is the sort of mix I do with tap water and rainwater, so I'm sure it'll be fine.> * PH was reduced from 8.5 to 8.2. (I am not planning to lower PH any further and will try to keep it stable.) <Cool.> * GH was reduced from 447.5 ppm to 411.7 ppm. (The test kit I bought is API. The instruction sheet says DH x 17.9 = ppm. This is how I got the figure. However, I found some other resources seemed to indicate DH times 10 equals ppm. Why is there such a big difference? <One degree of German hardness (dH, the standard measurement these days) is 10 ppm calcium oxide, but for historical reasons Americans tend to use ppm calcium carbonate, in which case one degree of German hardness is 17.9 ppm calcium carbonate. But you don't need to worry about the exact numbers. For all practical purposes, all you need to concentrate on is the "adjective" that goes with whatever test kit you're using. For mollies and other hard water fish, you want "hard" to "very hard"; for average community fish, anything between "fairly soft" and "moderately hard" is fine; for soft water fish like Apistogramma and rasboras, you want "soft". Concentrate on these terms, and forget about converting one set of numbers to another.> * KH was reduced from 268.5 ppm to 214.8 ppm. (Test kit is API as well.) <Fine.> I have a few questions though... hope you can give me again your precious opinions. <Will try.> 1) Is GH the same as TDS? Some places say yes and some says no. Kind of confused! The mixed water (tap+RO) measured TDS 269 ppm. After I added salt in the water, it changed to 600 ppm. But GH seemed to be about only 400 ppm or above. <TDS (total dissolved solids) and GH (general hardness) are certainly related. But they are not the same thing. Not all the dissolved minerals in water raise hardness. Sodium chloride, for example, as you've discovered. But these minerals conduct electricity, and TDS measures electrical conductivity. All this couldn't matter less in a freshwater aquarium where approximations of GH and KH are more than adequate for most species. TDS is more of a big deal in marine tanks because coral reef-dwelling animals tend to be much more fussy about changes in water chemistry. It should be mentioned this isn't an issue for all marine organisms: those that live in tide pools and estuaries are among the most tolerant fishes on Earth when it comes to dramatic changes in water chemistry.> 2) The nitrite level of the tank swifts between 0, 0.05 and 0.1 ppm. Any idea what may cause this and what I should do to improve? <The Holy Trinity of water quality: inadequate filtration, overstocking, and overfeeding. Check these, and make adjustments.> 3) High nitrate starts to be a problem. The nitrate level is still high at 40 ppm even after I made a 20% water change. I try to make a water change every 3 days to reduce the nitrate level but it does not seem to help. I am looking at several methods I gathered: <40 ppm nitrate is fine for most fish. Mollies aren't wild about nitrate, but since you're adding salt to the water, you should be fine. Please, make sure you're using marine salt mix, not tonic salt. Not all salts are equal!> - Mangrove plants (Hard to find a local store carrying this plant.... I am based in Canada) <Forget it. Growth rate far too slow to make much difference.> - Seachem de-nitrate (This is the only brand that designs the product from both freshwater and saltwater. Other brands such as Fluval and API, they indicate "for freshwater aquarium only. Since I added salt in the tank water for mollies, I am not sure if it is okay to use "nitrate reducer designed for freshwater only". What do you think?) <Forget it. Nitrate-removing compounds work well only when nitrate is low to begin with, e.g., in a reef tank or a discus aquarium. When you're at 40 ppm, they're going to be overwhelmed and expensive to run.> - Adding more plants in the tank (Kind of hard to find brackish water plants though) <This works, assuming the plants are thriving. There are LOTS of brackish water aquarium plants, far more than people assume! For nitrate removal, you want fast growing species that you can crop every week or two. Vallisneria, hornwort, Watersprite, Canadian pondweed, Cabomba, and Hygrophila will all thrive at SG 1.003 and even a little higher. Give them strong lighting and a good rich substrate (except for the floating plants, obviously) and these will grow rapidly sucking up the nitrate and killing off any algae at the same time. For specimen plants, Anubias and Java fern always work well in low-end brackish, and if you want some other brackish water plants that are bit different, then two brackish water specialists in the wild are Cryptocoryne ciliata and Crinum calamistratum. Both of these are gorgeous plants, slow growing, but tough and stately.> I know I can not keep making water changes every 3 days. I suspect this will remove some good bacteria from my tank and make the nitrite level unstable recently. <Water changes have ZERO effect on the "good bacteria". All the important bacteria live in the filter; there are hardly any anywhere else in the tank, so forget about them. Do as many water changes as you want. 50% a week I find works well and is a nice balance between effort and results.> Thanks for spending time reading my questions. Look forward to hearing about your advices again. <No probs.> Kathy <Cheers, Neale>

Mollies, Soft Water, Hardness, SG, Corys, Community Tank Questions 7/29/07 Hello from a senior citizen and younger bride in Georgia, <Greetings.> Many thanks for your wonderful efforts on this site. It is superlative and has helped immensely since we transitioned from marine tank to community tank. <Thanks!> Our goal is to have a colorful community tank with high quantity, hence 3 filter systems are in place. <OK. But do bear in mind filters don't really let you overstock an aquarium. At the very least, an overstocked tank requires more water changes per week than otherwise.> We have 8 separate problems/questions, with sub-questions having to do with either water chemistry or Mollies. <Eight questions with sub-questions!? Oh boy...> Forgive my husband's engineering training in outlining our tank and some of the questions. He wanted you to have ALL the parameters and orderly questions with no room for your guessing what we have here. <Good.> From reading your forum, we think that the LFS may have led us astray on Mollies and water parameters and we need a definitive answer and think your advice is what we want to trust. <There's no "definitive" set of water conditions for Mollies; there's what they inhabit in the wild (anything from inland lakes to the sea) and then there's what suits tank-bred mollies in aquaria. All I can say with 100% confidence is that mollies kept in brackish/salt water are less prone to disease percentage-wise than mollies kept in freshwater aquaria. But then, there are people who keep them fine in freshwater tanks. Just not everyone: for every person who has success with them in freshwater, there's another who has nothing but trouble. So it isn't easy.> We thank you in advance for your kindness in replying and apologize for the lengthy email. <OK.> Our tank and tank water parameters: 125 gallon tank, 5' long, est. 115 gallons water <Nice and big tank, always a good start!> Tank operating 15 weeks, popped normally with danios/platys, a few platys survived it all. <Should be mature by now.> Water changes 10-15% (12-20 gallons) a week with gravel vacuum each time. <Bigger water changes would be better, especially if you're after a heavy stocking of the tank. 50% water changes weekly are not out of line. At the least, you want to be doing 25% water changes. Big water changes don't take any more work once you have the bucket and pipe out, and dechlorinator costs very little. But big water changes *massively* improve water quality.> 11 plastic 'plants' & no live plants <OK. Livebearer babies appreciate live floating plants though, or at least, they hide among them well and avoid being eaten.> 4 plastic 'coral heads'-'lava tower'-'caves.' 1 small piece of slate for hiding babies and resting Corys. <OK.> 2 - 2.5 inches thick new white gravel with under gravel filter on 2 large corner power heads (no air bubble venturis in use) <The gravel sounds hideous. Here's a thing people don't realise about fake coloured gravels -- fish alter their colours to match. If you have bright white gravel, the fish will fade their colours. Instead of a rich reds and blues, your fish will gradually become pink and grey. This varies of course -- some fish (like fancy platies and goldfish) can't change their colours, but many can. Without exception, the darker the substrate, the brighter the fish's colours will be. Black is the best, but even plain gravel is good.> Fluval 305 and Fluval 405 canister filters (F-405 added this week to allow our high fish capacity) <Both good filters. But I think you're expecting too much from them. Even together, these will provide *adequate* filtration for a 125 gallon tank, nothing special. Here's the deal. An aquarium with standard levels of stocking with small fishes (danios, platies, etc.) needs about 4 times the volume of the tank in turnover per hour. Your aquarium has 125 gallons, give or take. The Fluval 305 gives you 260 gallons/hour, the 405 340 g/h. So, all told, 600 gallons per hour turnover. That's a bit under 5 times the volume of the tank in turnover. Doesn't sound so bad, does it? But those turnover quotes exclude two factors: filter media, and head pressure. When you add filter media (which you have to!) the turnover drops. Why do they give you the turnover without media? Marketing I guess. Secondly, when you place a filter under the tank, it has to pump water against gravity back into the tank (that's head pressure) and this reduces turnover further. Bottom line, you can lop 10-25% of the turnover quote for any given filter. By the time the filter has become clogged, that turnover will drop even more. So realistically, you have *adequate* filtration for your tank. More than enough to do the job, but provided you keep a reasonable number of fish.> Fluval's have the usual foam, poly-wool, charcoal, and ceramic. <I consider carbon to be useless in most freshwater tanks. Unless you clearly understand and have a specific reason to use it (as opposed to what the marketing says) I'd recommend putting its space to better use with some more filter wool or ceramic.> Charcoal changed monthly, poly twice monthly. <OK.> 1 air bubbler in plastic lava tower, 2 corner heaters Tank receives no direct sun. Ambient light is average. 2 fluorescent lights are on 8 AM-10PM. <OK.> Water crystal clear, no algae of any type present. <Famous last words.> Temperature 78 - 79 degrees. <Fine.> Salt added (2.25 teaspoons/gallon or 7.5 Tablespoons/10 gallons) to maintain SG of 1.004 (6 PPT) per 2 LFSs. (Leads to a question) <SG 1.004 is ideal for mollies.> pH 7.0 - 7.2 per LFS tanks where all fish are bought. (Leads to a question) Ammonia & Nitrites test zero using reagents, backed up with dipstick readings. Nitrates 20 on dip stick, might be as high as 30 with vagaries of the color chart. <Doesn't matter either way. 20 or 30 mg/l nitrate is pretty low. In a brackish water tank, where the salt detoxifies nitrate to a significant degree, this is basically very good water quality.> Well water only. (Please see Well water parameters below) Total Hardness GH always 75 on dip stick test at pH 7.0-7.2. (This leads to a question) <75 what? mg/l calcium oxide? mg/l calcium carbonate?> Total Alkalinity KH is always 40 on dip stick test with pH 7.0-7.2 (This leads to a question). <Again, 40 what? What's the scale on the test kit?> Food 2X a day: TetraMin Flake, shrimp pellets, and algae discs. <Fine.> Well water from tap: (we have our own well) Usually pH 8.2+ and will not drop over night alone, <For mollies, pH 8.2 with marine salt mix added is perfect, the champagne of waters.> We drive tap water pH down with powdered swim pool acid in a new trash can, let aerate for 3-4 days to stabilize at 7.0 - 7.2. <WHAT?????? You're using acid to change the pH? Look, pH doesn't matter if you don't soften the water as well. Since you're not softening the water, don't mess about with the pH. 99 times out of a 100, people do more harm than good playing around with the pH. Honestly, if you stick with hard water and brackish water fishes, your well water will be perfect for them. Add the marine salt mix, and bang, you'll have water they'll thrive in. Livebearers, glassfish, rainbowfish, gobies, various cichlids, various killifish, Monos, scats, archers... the list is very very long. So please put the bottle of acid down.> DeChlor is used. <Good.> It buffers back only slightly when we drive pH down and eventually stabilizes. <Your fish hate you for this, you know that?> Total Hardness GH always zero on dip stick test <WHAT???? Why on earth do you want zero GH afterwards? Nothing, not even cardinal tetras, appreciate water as soft as this. Mollies want something around 20 degrees dH (~200 mg/l calcium oxide). Even most soft water fish don't want anything less than 5 dH (40 mg/l calcium oxide). Zero hardness is practically toxic.> Total Alkalinity KH always 80 on dip stick test <Oh boy. I've kind of lost track really of what's going on here. What you've created is some weird cocktail of salts that your fish don't want. And then you're adding salt. Doesn't make any sense to me at all. Your well water is fine. Mollies will thrive in it. The harder the better, as far as they're concerned.> Addition of DeChlor and pH Down to make water 7.0-7.2 does not change GH or KH <Don't focus on pH; it's a mirage. The deal with pH is that it moves up or down depending on the hardness salts in the water. In most places, water either lacks hardness salts, and becomes acidic because of organic decay, or else has lots of hardness salts, and becomes alkaline/basic because of these salts buffering the pH upwards. But the pH isn't the "cause", it's a "proxy", a thing that changes alongside the thing that matters, the dissolved minerals in the water. Freshwater fish couldn't care less about pH really, and most will adapt to a wide range of values. What they care about is the "total dissolved solids", the minerals in the water, and the stuff the influences their osmotic balance.> Addition of aquarium salt to make SG 1.004 (2.25 teaspoons/gallon) does not change GH or KH <Don't use aquarium salt. It's rubbish. Use marine salt mix (instant ocean, reef crystals, etc.) Marine salt mix buffers the pH and does a lot more than just raise salinity. Your mollies will love you for it.> After sitting to stabilize for 3-4 days, either in clean 5 Gallon buckets or new trashcan, the GH goes to 75 and KH goes to 40 (Leads to a question) <At this point I've pulled out a lot of hair... so let's move on swiftly...> Live Stock: Total 36 fish, approx 73 inches. 15 Platys, various types. <They will enjoy your well water as it is.> 6 Cory Cats <Assuming you don't have anything delicate, these will adapt fine to well water. Not wild about salty water, but if you adapt them slowly, should be OK. But next time you're shopping for catfish, pick a brackish water tolerant species like Hoplosternum littorale or Hypostomus plecostomus.> 8 Swordtails, various colors <Like the platies, they'll thrive in well water.> 7 Mollies, Gold, silver, black, Dalmatian. (Which leads into a question). <Not only do they like well water, they positively hate the water you're trying to create with all the messing about with pH.> Question\Problem 1: Mollies are dying, mostly the males, all 4 color types in 4 - 14 days. We are selecting good fish at the LFS. The ones that get sick and die don't look any different to us in the store then the survivors. The Mollies that we lose begin to meditate head up, tail down, and stop competing for food or eating, mostly start to shimmy and not swim around, the fins droop and become limp, and then they die. Some settle listlessly to the bottom without shimmy, and then die. There is no sign of rapid gill movement, but the mouth opens and closes a lot (like a carp!) on some. Presently the male Dalmatian and male black molly exhibit this behavior; a gold male died this week, a female black died this morning after 14 days, last 3 days unhappy. The other 6 females (gold, Dalmatian, silver, black) appear normal in eating and swimming and are 14 days in the tank. We have lost about 8 previous Mollies in the last 6 weeks. All other fish are normal excepting two shy swords. No fish pick on other fish. No ich or sores evident anywhere. Pellets/flake food are spaced to give the ill ones equal time for food, which they ignore. The sick Mollies may prefer either the bottom or surface of the tank. We read about the shimmy medicine for lack of electrolytes but that seems a long shot as others posting have not indicated success with Shimmy Block or Molly Bright (and all our Mollies are not sick). Any thoughts so far, considering our pH, GH, KH? We do not know how to change KH if that is needed or what causes it to change from tap to tank. Ditto no knowledge on GH. The LFS (PetS) said they keep (and we should keep) pH at 7.0, slipping to 7.2. The LFS does this for the entire store of all fish except the cold water fish. Doesn't agree with your site. We elected to follow their lead believing the fish would be safer with the same water in our tank as the LFS. I tested the LFS water and it is indeed 7.0 pH and 1.004 SG and 78..degrees in the continuous community tank. <OK, I don't need to read much of this to know why. Knock off messing about with the well water. From now on, just add the well water plus salt plus dechlorinator. For the sake of the Corydoras, aim for SG 1.003 for now. Things will gradually improve and your mollies will recover.> Your forum says Mollies need 7.5 pH and hard water. Is raising pH slowly to precisely 7.5 really necessary? We can do it, but what effect will it have on the Cory Cats, platys, and swords? <Apart from the Corydoras, all your fish actually prefer "liquid rock" well water as hard and as alkaline as it is. It's what they like. The Corydoras not so much, but they'll adapt.> UGH. It appears this would stress all the fish. (If we were answering our own email, here is where we would say "UGH, indeed!"). <Your problem is trying to create water conditions with a certain set of values without understanding what all those values mean. Go read this: http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm > What is the lifespan of a full grown Molly? Lastly on Q1, is this shimmy something only Mollies do when ill or stressed, and can it mean many things or only one thing? (My engineer husband threw that question in, hoping for a black and white engineer type answer). If you feel there could be multiple chemistry problems, we would like to try solutions one at a time to reduce stress on the whole community in the order of priority of change KH, GH, pH, SG, etc. <Mollies live a few years, maybe 4 or 5, all things being equal. They aren't really long lived fishes in the wild or in aquaria, and inbreeding hasn't helped.> Question 2: Can we successfully keep Mollies, Cory Cats, Platys, Swordtails in a tank together or are we beating our heads against the tank? We do not want to do an all Molly tank unless we could also do Cory Cats with them. We enjoy Cory Cats (like small puppies!), the graceful sword tails, and the "front of the tank" platy parade and could go Mollyless as an option, depending on your response. You can see we are trying to do it all, and of course LFS sells us all without hesitation. If our current whole combination won't work, what pH and SG do we need for only these two solutions: (1) Mollies and Cory Cats? (2) Cory Cats, Platys, and Swords? Is the SG of 1.004 ok for these fish if we go without Mollies or should it be no salt at all? Our book sez pH of 7.0 for Corys and no salt. Will they die at pH of 7.5 and the salt in the range we have (1.004) or the range your site suggests for Mollies (1.002-1.003)?. What effect is: The soft GH of 75? The alkalinity KH of 40? on either of tank (1) Mollies/Corys or (2) Corys, Platys, Swords? <OK, all three livebearers will thrive in brackish water at up to pH 8, "very hard", and salinity SG 1.005. Corydoras are adaptable, though this depends on the species. Your standard issue peppered and bronze Corydoras really will thrive at anything from pH 6 to pH 8, and from 5 dH up to 20 dH ("very hard") hardness. Wild caught and more sensitive Corydoras are a bit less adaptable perhaps, but still, they're pretty tough little animals. Mollies couldn't care less about the salinity. They can be kept at anything from 1.000 (freshwater) to 1.030 (hypersaline, more salty than the sea conditions). A low to middling salinity (SG 1.003 to 1.005) is probably the best in terms of getting the best health from them while leaving your options open in terms of tankmates.> Question 3: Why does the well water out of the tap, at GH zero, KH 80 (dip stick test, with no immediate change with DeChlor, pH down (to make 7.0-7.2), & salt added), change after sitting 4 days, to GH 75 and KH 40? It remains at these numbers in the buckets and when added to the tank, so it is not a change happening in the tank. If you didn't catch this in Q1 or Q2, Do we need to adjust KH and GH? How do we adjust KH and GH to your specs and not change pH? <I have no idea what's going on with your well water because you're doing crazy stuff to it. Just use it as it comes, and let the fish adapt to it. Adding the marine salt mix will stablise the pH and balance the minerals in the water nicely, making the whole issue academic. Tell me what the pH, GH, and KH are of the water you have STRAIGHT OUT THE TAP, and give me the UNITS on the test kit, not just the numbers. (Without the numbers, it's like saying it's 0 outside without stating if that's Celsius or Fahrenheit.> Question 4. We don't have algae on the tank walls for the LFS standard\common $1.00 gold color snail (Ramshorn or Florida Apple, sorry no species). It died in 6 days after crawling the clean walls and being quite active. It was not on the gravel much, preferred the tank walls. Do you think it was the SG of 1.004 or the lack of food? Was it supposed to find uneaten food on the gravel? If we were supposed to feed it, what do we feed it? Can we keep a snail under the water chemistry we have (salt added)? <Forget about apple snails. They're a poor choice in your aquarium for a whole bunch of reasons.> Question 5: We notice that our salt added to maintain SG 1.004 is triple the 1 Tablespoon per 5 gallons directions on the salt jar and over double your suggested 1 teaspoon per gallon and a higher SG than your suggested 1.002-1.003 in the forum. (We are following 2 of the LFSs with this SG of1.004). When we used 1 Tablespoon per 5 gallons, it did not register on our Instant Ocean Hydrometer, which seems accurate in measuring 1.004. How much latitude on SG do we have for the fish we want to keep, knowing the Cory's are most sensitive (at 6 weeks here, Corys are fine with SG 1.004). <OK, I'm not a fan of measuring salt by volume because, as you've discovered, IT DOESN'T WORK. For your aquarium, you're aiming for SG 1.003, which is roughly 6 grammes of salt per litre (about 0.8 oz per US gall.) Make up the salt by adding it to the bucket... and then test the SG using a hydrometer. A basic floating glass hydrometer will cost you all of $5 and make life 100 times easier. SG 1.003 should be perfectly safe for your Corydoras.> Question 6: The LFS operates all community/semi aggressive tanks on the one big tank plumbing system, is that a contagious disease worry on a fish buy? We don't have a hospital tank. Should we set one up and routinely quarantine each new fish from the LFS (PetS) with an anti-bacterial med as we used to do with copper on marine fish? If so, what medicine for routine use? We hope this is not necessary, but it goes back to these Molly problems. <Quarantine tanks are always a good idea. That said, the mollies are dying because of what you're doing to them, not because of the retailer.> Question 7: What medicines can be put in the big tank to prevent contagious disease (ich, bacterial) or cure one fish, without destroying the good bacteria? (Just planning ahead, since we don't have a hospital tank). <For now, don't worry about it. As and when something goes wrong, you simply buy an appropriate treatment. There are any number of brands out there. But for now, I'd sooner you bought/borrowed a book on fish health, and read that. A much better investment of your time.> Question 8: Is there one flake food for all live bearers? The Mollies are said to need veggie flakes in one forum and are said to be omnivores in another forum so that is confusing to see. How about swordtails and platys, veggie or fishy flakes or either? The TetraMin flakes we use says parts of: "Fish meal, shrimp meal, algae meal, rice, wheat, potato, oats, soy" and a list of stuff we can't pronounce or read. Is this OK for fish we have when used with shrimp pellets and algae discs? It seems to be an omnivore food, not entirely veggie. <There is livebearer flake. It's sometimes sold as Spirulina flake or guppy flake. Lots of brands. I happen to use Wardley Spirulina but other brands are just as good. The main thing with flake food I think is to buy *small* pots, as it loses its savour within a month or so. If you must buy in bulk, consider dividing the tub up, and freezing most of the flake you're not about to use.> Many, many thanks and cheers, Rosemary Brekka <Phew! I think we got to the bottom of all of this! Good luck, Neale>

Mollies' eating my plastic plants -- 06/11/07 Hi, <Hello.> A couple of questions for you? <OK?> I live in the UK in Devon. I have just started keeping fish, well 12 days ago. I got my first fish a black Mollie and a silver Mollie three days ago. They are doing ok. I have a 35 litre tank, with plastic plants. <Your tank is probably a bit small for mollies. Bear in mind some species can get to 15 cm in length, if not more, and most of the common varieties in the trade will certainly be in the 5-8 cm bracket when fully grown.> I have noticed bite marks in the plants. Are they just testing or should I get them some real plants. <I couldn't imagine mollies actually damaged plastic plants, so that's a first to me. Anyway, they are doing their level best to demonstrate their need for green foods. Use vegetarian "livebearer" flake (NOT generically tropical fish flake except as a treat) plus green foods like Sushi Nori, blanched lettuce, algae wafers, sliced cucumber, tinned peas, etc. Mollies are herbivores in the wild, so try and match that in captivity.> If I do what plants would you recommend considering I plan to add a small salt content. <Almost all hard water tolerant plants thrive at the low specific gravity (SG 1.002-1.003) mollies relish. Java fern, Java moss, and Anubias are perhaps the best plants because they come attached to bogwood so are easy to "install" without fussing over substrate. They are also ignored by most herbivorous fishes. Failing these, Vallisneria, Hygrophila, Elodea, Ceratophyllum, Cryptocoryne wendtii all work well in low-end brackish tanks.> (Not changing over fully just adding the 1tsp per 5ltrs that everyone recommends. <Don't trust anyone who recommends "spoons per litre" amounts, because it's a meaningless measurement. Once the box of salt is opened, it absorbs water, so over time, each teaspoon contains less and less salt. Ideally, use a hydrometer to measure the specific gravity. A basic floating glass hydrometer will cost about £5. You want about SG 1.002-1.003, or 5-6 grammes of salt per litre. Make up the brackish water as per the instructions on the box, and then measure the specific gravity (SG). Add more water or salt as required.> Also I have read many articles especially on your site regarding adding a little salt. I plan to do this on the next water change. I have added the salt to the new water and plan to add the water slowly as I refill the tank from the water change. Is this a good idea? <Adding salt to the water before adding it to the aquarium is exactly correct. Don't forget that any time you top up the tank due to losses from evaporation, *that* water should be freshwater without salt. The salty water is only for water changes.> Thanks Doug <Cheers, Neale>

Hi I just bought some sail-fin mollies and one is a male and the other is a female. -- 05/08/07 <Nice fish. Please remember sailfin mollies are extremely intolerant of nitrate and are best kept in brackish water with about 3-5 grammes per litre. While they can be kept in freshwater, nitrates have to be as close to zero as possible, or else they are VERY prone to fungus, fin-rot, and the "shimmies". Finally, hard, alkaline water is ESSENTIAL: pH 7.5-8, hardness 15 dH upwards. Be sure and provide lots of swimming space and green rather than meaty foods. Many people fail with mollis because they ignore their needs. They aren't easy fish, but full-grown adults are spectacular animals. Please read through http://www.wetwebmedia.com/FWSubWebIndex/poeciliids.htm and related articles/FAQs.> How do i know if she is pregnant or its just her body structure that cause her to look plump??? <You can take it as read she's pregnant. Yes, the females become a little plumper as the baby fish develop. But because mollies are so large and sturdy, the "gravid spot" observable on other livebearers normally isn't visible. Your main issue with mollies is to make sure the babies aren't eaten by the parents or other fish. Adding lots of floating plants, such as hornwort, will fix this problem. Under no circumstances put mollies in floating or net breeding traps. Mollies are horribly stressed by these things. Cheers, Neale>

Black molly question... beh./sys. 4/10/07 Hello WWM, <Didi> I just found your website, it looks like an awesome collection! I looked through molly questions but couldn't find anything that answers my particular question, so here it is. <Okay> I have a black male molly and a red female swordtail in a small new 3 gallon tank. <Hard to keep such small volumes stable... do be diligent re maintenance... weekly water changes (maybe a gallon) and careful re feeding> I bought them a month ago and so far they've been getting along fine, mating and all. The female got pregnant and today started giving birth, and since she has been doing that, the male has been viciously attacking her! I've had mollies and swordtail fish before, for years, and know what they look like when they're horny or mating... and that was not it. The male would charge at the female in short, fast bursts and bite her. <Likely simple territoriality at play here... not enough room...> She'd dart away and slam into rocks, walls, etc. It looked pretty bad, so I isolated her in a smaller tank <! Needs more room, not less...> to have her babies in peace. Since I did that, the male has been acting normal. She hates the small tank though (about half the size of the other one, so not too small), and is flinging herself at the walls, so I may try to put her back again tomorrow. I've never had males attack females like that before, in labor or not... What's going on? I don't want to stress her out and am afraid to bring her back now :( Please help! Thanks, Didi <These fish need at least ten gallons... Bob Fenner>

Re: My Mollies (information on addition of salt) 3/5/07 <<Hey, Ashley.>> Okay, I'm back and this time I have salt. It's API (Aquarium Pharmaceuticals) Aquarium Salt. I opened the carton and it looks like Epsom salts. Now how do I add it? Do I just dump the granules into the tank or to I have to dissolve them first? All at once or in little bits? The instructions on the side of the box aren't very helpful. <<Well, let's see if I can be more helpful than a box. First, you never want to add salt straight to the tank. Undissolved salt will cause burns if it comes into direct contact with the critters. So, and I state the obvious here, you'll want to dissolve the salt completely in fresh, conditioned water during water changes. (A little 'swirling' will speed up the process a bit.) Now, let's say you do a 20% change to your 10-gallon tank. First time through ONLY, dissolve two 'light' tablespoons of salt into the new, two-gallon batch of water. (We don't want to overdose the Oto.) Once this is added back to the tank the solution ratio will be one tablespoon per five gallons of water'¦or at least close enough for our purposes. On subsequent changes, you'll need to add one-fifth of a tablespoon of salt for every gallon of water you remove. (Do NOT add salt if you find the need to 'top off' your tank due to evaporation. Salt doesn't evaporate with water. It just makes the water left in the tank 'saltier'.)>> Thanks for all your help Ashley ... again <<You're more than welcome, Ashley. If I didn't do better than the 'box', you know where to find me. My best. Tom>>

2 Mollies and 1 Betta in a 2.5 gal. Aquarium - Not Enough Space - 10/18/06 Hello, <Hi there> I have a 2.5 gal tank with 2 black mollies and one beta. <This tank is not big enough for mollies - would be a perfect beta home. Definitely not big enough for 3 fish.> One of my mollies is extremely skinny, you can see her bones, she eats but spits it out, does not like the food, or is something wrong? or is she just skinny?? <Have you recently tested the water for ammonia, nitrite and nitrate? Have you recently changed the water? My guess here is poor environmental conditions...> My other molly is normal - she was really big but is skinny now. <Likely pregnant, now not.> I didn't find any babies except for one, but it was dead. Could it be because its her first batch? she is pretty small in length? <Could be that, but the mollies or the beta could well have eaten the fry. You are correct, though, in that a female livebearer's first batch of fry is typically quite small...> When she's going to give birth, should I shut off the filter? <Not necessary. I would suggesting getting at least a 5 gal. tank for the mollies, better a 10 gal.> I have read that mollies like water with salt in it...is it safe to put in salt with the beta? and how much? <Again, another reason to separate the fish. A little aquarium salt likely won't hurt the beta, but I don't recommend it. Separate the two species - add aquarium salt or marine salt to the molly tank (either as per directions on the FW aquarium salt container, or use a hydrometer/refractometer to measure salinity...mollies are undemanding re: salinity requirements, but just don't increase more than 0.001-0.002 per day.> Thank you for your time!!! <You're welcome. Read here for more info.: on the two fish you have, and also establishing a freshwater aquarium: http://www.wetwebmedia.com/FWSubWebIndex/poeciliids.htm http://www.wetwebmedia.com/FWSubWebIndex/bettasysart.htm http://www.wetwebmedia.com/FWSubWebIndex/fwtanks.htm > Allison Fahey <Best of luck, Jorie>

Pot Bellied Mollies 10/4/06 Thanks for your help. I got 7 new fish (including the mollies) the day before she gave birth and the day after that another balloon molly (the new ones i bought) gave birth. So I'm waiting for it to cycle. How long does it take to cycle? <Variable... weeks to a month or more, depending... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm and the linked files above> Also, what do you suggest i test besides the ph, ammonia, nitrate, and nitrite. <This is about it... unless you start using salt/s (often useful with many Molly species)... in which case I'd get/use a hydrometer> And, I don't know much about neon tetras and balloon mollies so I wanted to ask what temperature they prefer and what ph level they prefer? <Shouldn't be housed together... "Like" very different water quality... See WWM re both...> Thank you again for your help. This site is a great help to me! I feel so much better now that i found somewhere where i can ask questions and have them answered quickly. Tiffany <Time to start reading, and not asking... BobF>

Re: Pot Bellied Mollies 10/4/06 I forgot to ask you.... How do you know when cycling ended? Can you send me some pictures of male and female balloon mollies so i can learn to tell them apart. <See WWM re> Molly Concern - 09/10/06 Hello, <Hello there, you've got Jorie tonight.> I have been reading your website for tips on caring for my Mollies since I have gotten them. Thanks for all of the advice! <You're welcome - that's what we're here for!> That being said, I have a concern about on of my female mollies. Currently I have a 10 gal. tank with 5 mollies, 2 female gold dust, 2 female Dalmatians, and 1 male Dalmatian. I had an additional male gold dust, but lost him to new tank syndrome. =( <Hmmm, sorry to say "new tank syndrome" is really not a disease, but simply has to do with the new fish owner adding too many fish, too fast, to an unestablished system. If the nitrogen cycle is established (fishes), prior to adding any livestock, this will never happen. Read here for more info. on cycling: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm Also, since you're tank isn't huge, I wouldn't recommend adding any more male mollies to the mix...sometimes it's fine, but other times, the one of the two males will terrorize the other, in an attempt to declare his "alpha-ness". In all reality, if you have a 10 gal. w/ these 5 mollies, you're fully stocked, in my opinion. The mollies will grow to anywhere between 3-5" each, and they sure poop a lot!> Anyway, the concern I have is about one of my female Dalmatians. She has a green spot on her belly. It is on her left side in approximately the middle of her abdomen. It doesn't look like an external growth and she still has her iridescence. <So no protrusions? Could just be coloration. Have you recently tested water parameters (ammonia, nitrite, nitrate, pH) - if not, do so. How often do you do water changes in this tank, and what kind of filtration do you use? As mentioned above, mollies are pretty messy and produce a lot of waste, so the level of environmental toxins is something to keep an eye on.> She has developed a tendency to hide under the fake rock in the tank. She'll come out once in a while, and will come out for feedings, but she doesn't go to the top of the tank like the rest of them do, instead, just picks the food from the gravel. She also looks fatter than the rest of the mollies, like she's bloated or something. <Oh, now I see! She's likely pregnant! Females, when pregnant, can slow down and tend to hide more. After verifying that the water conditions are good, I'd would just leave her alone, of course keeping a good watch over her. The spot you are referring to could just be the darkness of the eyes of the little fry inside her belly! You said she was eating, which is a good sign. For now, let her rest, make sure she isn't picked on, and just wait patiently.> Her gills look fine, and she doesn't look like she's laboring to breathe. Her movement is straight, and her fins are not clamped in the slightest. <All excellent. I still believe you are an expecting fish grandma!> I've tried taking a picture of her and the spot to include with the email, but she is being very camera shy. She could be swimming around the tank, but when the camera comes out she immediately goes back under the rock. I've even tried my camera phone thinking that it wasn't big like the actual camera, but she hides for that as well. <It happens. Don't stress her out, as it could interfere with her pregnancy. Give it some time, and I'm pretty sure she'll give birth on her own. OF course, if the symptoms should change, then we'll have to re-address.> When my male gold dust died, I had the water tested at both the PetCo that I bought the fish from and the "specialty" aquarium store in my town. PetCo (which tested with the dip strips) said that everything looked good... <Those dip strips are notorious inaccurate. You should invest in your own test kit - I like Tetra's Master Test Kit. Easy to use, easy to read.> ...however, the aquarium store said that my bacteria was slightly low <...have NO idea what they mean by this...> and my ammonia was slightly high, <...OK, that's bad. Do a 50% water change ASAP if you haven't already. Ammonia and nitrite should always be at zero, 20 ppm is the high-end of acceptable for nitrates (but lower is better). Also, when relying on fish stores to test your water, make them give you the actual readings for the above-mentioned parameters. Some people's definition of "low" and "high" aren't the same as other peoples'...> ...but did not give me exact figures for either. <See above.> I have since treated the tank with bacteria and an ammonia break-down compound. <There is no need for this - just keep up with regular water changes and the bacteria will establish itself, and the ammonia will be removed. I'm not a fan of products such as these, as I believe they give folks a false sense of reliance, and they then shirk they water-changing and filter-changing duties. Do read that link on cycling provided above.> I have added 2 TBS of aquarium salt. <That's great - I was going to suggest it. Mollies do appreciate a bit of salt in their water. Remember, salt doesn't evaporate, so you only need to add more when you do water changes, not when you top off due to evaporation.> Please help, because I can't find any information on any sort of green spots anywhere and I'm concerned about the molly. <In all honesty, I've not seen an actual "green" spot as you describe, but everything else leads me to believe your fish is pregnant. If you look at her belly very closely, is she somewhat translucent? Can you see little fry in there if you try hard enough?> Thanks so much! <You're welcome. Let me know should things change. Jorie> <P.S. Here's another helpful links: http://www.wetwebmedia.com/FWSubWebIndex/fwtips4beginners.htm> Re: Molly Concern - 09/10/06 Hello Again! <Hi> Thanks so much for the advice. I did a partial water change (25% one day and 25% two days later as to not stress out the Dalmatian female too much) and had the water re-tested. The aquarium store said that my ammonia levels had dropped to .5, still a little high but it will fall now that my bacteria was established. <Ammonia needs to be a ZERO at all times there are live fish in your system...do another water change ASAP. Also, it really is worth the $25 or so to have your own test kit on hand...no need to make extra trips to the store, and much more reliable.> Oh, and my female Dalmatian did have babies. <Wonderful! Do you have fry food for them? If not, crushed flake food ('till you have a power-like consistency) works well...> And now that I know what to look for, I think that one of my female Golddust mollies are pregnant. <It seems as though there's always at least one pregnant molly in my livebearer tank...you'll soon have more babies than you know what to do with. My platys are in a community tank w/ boesemanni rainbows, and this takes care of the overpopulation issue nicely. The mollies live with a knight goby, who does his part as well...> Such is life, I guess. The little fry are cute though. <Yep - I always get a kick out of how very small they are!> Anyway, I just wanted to say thanks again for all of your help. Keep doing what you are doing, because it sure is helping! <You are most welcome. Enjoy your fish!!> Mindi <Jorie> Balloon Mollies in 10g tank that housed goldfish which died... Goldfish health, Melafix, Molly Sys. 8/8/06 Hi Bob, <Anish> I found your site today while searching for information on Balloon Mollies. Love the site. It looks like a place for compressive and complete information on maintaining aquariums. <We try> I have a 10 gallon tank in my office that housed a single small fantailed goldfish and two live plants. <Now nice> I have a filter that cycles 100 gallons per minute. Nothing else. I had this setup for a little over a year and my little Princess (originally my daughters goldfish) prospered. A lot of people in my office complained that Princess was lonely and needed company (as if I was not enough!) <Mmm... they are wrong here... anthropomorphic... Other life is not "like humans" necessarily> So my wife bought me a black fan tailed gold fish who was nearly twice as big as Princess - Al Capone. <A fitting name here...> Al Capone bullied Princess on the first day but after that left her alone. However pretty soon Princess began to show symptoms of stress. She got ick and died. I couldn't tell she had ick because of her color. I only realized it was ick because Al Capone also developed the white spots. I immediately treated the water with Wardley's Ick Away but I was too late. Al Capone also died. I followed the instruction and removed the carbon filter when treating the water. This was my first experience with Ick. I had never even heard of it before. I changed about 75% of the water and treated the water with Ick Away and Melafix and left it for three weeks. Got the water checked and was told by the local pet store that everything was good. <Mmm, I would have "nuked" the tank... done a biocidal bleach wash...> This time I got two really small fan tailed goldfish (silver was James Dean and the gold was Skippy) and two snails (apple I believe - Speedy and Sleepy). The very next day there was ick on James Dean. <... might have come in with it/this... or gotten from the existing tank... a resting stage> As soon as I added the fish I added Melafix also (as it says on the bottle to treat for three days when adding new fish.) <This "medication" will not really "treat" anything... Particularly not a protozoan infestation> So I added Ick Away and some more Melafix. Two days later James Dean was dead and two more days later Skippy was also dead. <Do you see a pattern here?> As I was treating James Dean and Skippy I also noticed these really small transparent worms in the water. I could only see these because the aquarium is against the my window (no direct sunlight). There were quite a few of them - I couldn't count how many. Their sizes ranged from 2-4mm in length and could easily be mistaken for just particles in the water except for their rhythmic twitching (like someone bending and opening a finger over and over again.) I took the worms to the pet store but they couldn't tell me what it was. <... could be flukes... other worm phyla... Require microscopic examination to determine down to the phyletic level> They also told me to raise the water temp so I bought a heater and heated the water up to 80f. None of this helped. I should add that once I put the carbon filter back the water cleared and the worms disappeared. <...> Apart from the ick the only other common symptom on all the fish was the blackened stomach. I checked your site for fresh water diseases but I could not find any mention of these worms or the blackened stomach symptom. <Look for the terms "Fluke/s", "Monogenetic trematodes", "Digenes"> The two snails are doing fine though. <Likely vectors here> I don't think I had the correct diagnosis. I think Al Capone brought the worms to the aquarium. <Maybe... but much more likely the snails> Ick was probably a secondary as the fish were stressed by the worms. <Possibly> Now, I have taken the tank home and am trashing the gravel and the plants. I am going to clean the aquarium with boiling hot water to kill any eggs etc. left by the worms. Will try to do the same with the filter assembly and bio sponge. <Please read here: http://www.wetwebmedia.com/clnornart.htm and the linked files above> I want to try Balloon Mollies this time. I'd like to have five of them (four females and a male). Is a 10 gallon tank big enough for five balloon mollies? Would you suggest three instead of five? <Is big enough> I'd like to reintroduce the snails to the new setup. Do you think there is a chance that the snails my be carrying the worms? <Yes. I would keep these isolated (in a jar should be fine) for a month or more> The last time I set up the tank it was just a question of adding plants, gravel, water and treating the water with Seachem Prime and then adding the fish. I read that I should add some salt to the tank and have the water heated to about 80f. <Mmm, a bit high... I'd set the temperature in the mid 70's F. range> How long should I have the setup before introducing the fish to the aquarium? <Till it cycles... see WWM here: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm> Should I add Melafix when introducing the fish to the aquarium? <No... is worthless... perhaps worse than worthless... as it gives folks a false sense that they're actually doing something... and they're generally not> My aquarium does not have a cover. <I would get/use one...> As a result nearly one gallon evaporates daily that I replenish daily with Seachem Prime treated water. I keep the aquarium filled so its almost overflowing. Is this OK? <No... the Mollies may well jump out as well> Do I need to have a bubble/air pumping machine? <Do need to have filtration... See WWM re Molly Systems...> Sorry for the long email and my many questions. I look forward to your reply. Regards, Anish C. <Take your time here my friend... Bob Fenner> Re: My poor Molly... sys., dis. - 4/11/2006 Hi Crew, <Lisa> I wrote in a couple of weeks ago about an overstocked tank (2 black mollies, 1 gold dust molly, 1 red platy) -- went out and bought a 6.6 gal. tank, which I set up a couple of weeks ago. This tank and my 1-gal. for the betta are in my office (betta is loving it here -- lots of attention). Right after I got your answer, the bigger black molly came down with ick, so I quarantined him and treated with kosher salt and RidIck -- he's much better, though recently developed one other little spot, so I'm keeping him at home, doing 25% water changes and medicating daily -- will do so until he's spot-free for a couple of weeks. I also treated the 2.5 gal with the black molly, gold molly, and red platy proactively, and they seem fine. However, the gold dust molly has begun resting on the bottom of the tank. He eats, though less than before, and after he goes up toward the surface for food, seems to just quit trying and sinks like a stone. There were a couple of days when he seemed a lot better -- peppier, swimming around more -- but today when I brought him to the new tank in the office he just did the same thing. His fins look OK, he doesn't have any red sores and no white ick spots -- he just seems exhausted. <Might be> I moved him to a shallow container alone, thinking that the stress of moving might be making it worse. He's not gasping; I just really worry about him sitting/scooting on the bottom. Is this a swimbladder disease, and if so, how do I treat it? <Mmm, likely "salt/s" and time going by best here> I feel terrible because he was such a lively little guy and now he just seems so bummed. Could I have poisoned him by preventatively treating the tank? <Oh yes. Very common> I don't want to euthanize him unless it's absolutely necessary, but I really don't want him to suffer. Thanks in advance for your help. <Please read here: http://wetwebmedia.com/FWSubWebIndex/mollysysfaqs.htm and the linked files above, part. on Molly Disease. Bob Fenner>

Ammonia level in Molly Tank 3/24/06 Hello <Hello, Pam. Tom here.> Back in October I bought Mollies (turned out to be 2 females and 4 males) to go in my 65 gallon tank. <Okay. Would like to see the ratio reversed but,...> Didn't know they gave live birth. SURPRISE! <I can imagine!> The black female started having babies about a month after this. Found the info on your sight about saving the fry. <Good> Have been VERY successful with this. We now have about 40 mollies. <You have, indeed, been very successful!> Santa brought both my sons 10 gal. tanks for Christmas. We placed 3 of the adult males in one tank and the 1 adult male with 3 of the fry that were large enough in the other. <You don't say when but, I'm guessing too soon> We have had continued ammonia problems with the two 10 gal. tanks. We lost the 3 in the one tank and have had a constant battle with the other. <Pam, I'm not "guessing" any longer. The fish were added too soon> I have done partial water changes <Good>, treatment with AmQuel <Not good and, I'll explain why. Products such as Amquel convert ammonia (NH3) to ammonium (NH4). (Bear with me. You, honestly, won't need a degree in chemistry, I promise!) Ammonia is extremely toxic to fish - literally burns the gill membranes. Ammonium doesn't. However, the beneficial bacteria that your aquarium needs to "cycle" don't feed on ammonium, they feed on ammonia. The upshot? Amquel, et. al., starves your tank of exactly what it needs to properly cycle and establish the bio-colonies that make the tank healthy. An oxymoron-type situation? To be sure! To get a leg up, so to speak, look into Bio-Spira (Marineland). Expensive but, the product contains "living" bacteria that greatly speeds up the cycling process. (Don't waste your money on other products that make a similar claim. Bio-Spira must be refrigerated. Off-the-shelf products don't contain what you need. Period.) In the meantime, keep up with regular water changes. Best maintenance you can do> and even tried breaking them down completely, doing a new set up (rocks, plants, added underground filter <Please, rethink a UGF. In fact, throw it out. Will likely lead to problems as bad as what you have now> etc.) and refilling from the large tank which has perfect ammonia levels. <Water alone won't do it. Will help but bacteria dwell on the "solids", i.e. filter media, substrate> Within hours the ammonia level is right back up. <Yep> My pet store said the only thing I had to really watch was the ammonia level and told me I didn't need to check anything else. Based on what I read on your sight, this doesn't sound right. <Advise them to us. There's much to know that they aren't sharing with their customers> Any suggestions on how to remedy the ammonia issue? What else should I be testing for? <Nitrites (as important as ammonia), Nitrates, pH, to name a few. Aquarium Pharmaceuticals has an excellent Master Test Kit for freshwater aquaria. Nice starter kit> Thanks PH <Feedback is always welcome, Pam. Hope I've helped. Tom>

Mollies without salt? 3/23/06 <Greetings, Vicky. Tom here> I am about to be given the dubious gift of three mollies that a friend wants to flush <I most sincerely hope you don't mean that literally>. Not that I have anything against mollies! <Nor they against you, I'm sure> Still, I'm scrambling to find somewhere for them to live. I have an empty 10-gallon and a spare filter that I keep cycling on the main tropical tank. <I do the same thing myself> That community tank is several years old, but is at around a pH of 6.5 or so (too low for mollies, right?) <Correct. Mid-range would be 8.0>. I can pilfer plants <Hold off on the plants unless they're artificial. I'll follow up as we go> and gravel from that tank, as well as the spare, cycled filtration. For the 10g, I have an extra heater. <Excellent> Do I have to use salt and, if so, what sort? Do I use the aquarium salt or the marine saltwater salt mix? How much do I need? <Aquarium salt is what you'll need at a mix of one teaspoon per five gallons. Marine salt contains buffers and isn't prescribed here> Regrettably, I have less than a day to put everything together. I have the water set aside in buckets <Good> and the pH leveled out to about 7.5. <Low but within range> Can this work? <Yes> I know it's not ideal, but the only other solution I can see is to put the mollies in the community tank at too low a pH. <I'd rather see you go with your former plan> It's a peaceful tank, so I'm not sure how things would go. Any advice would be sincerely appreciated! So much for friendship, eh? Vicky <Above and beyond. My respect for caring about life, though. Tom>

Re: mollies without salt 3/23/06 Just to clarify, the other tanks I have are a 35 gallon housing tropical fish and a 28 gallon with a solitary Oranda. The spare tank I have is a 15 gallon (it turns out) and was my quarantine tank when I did saltwater. It's not set up right now. I have access to a hydrometer, if I need one. <Probably not necessary at this point but good> Eventually, I plan to set up a permanent larger tank for the mollies and get a few more, but not this week! <Don't blame you> The water in my area is naturally soft and acidic, so moving the pH up and keeping it there will be a bit of a challenge. <Easier to move up than down in my experience> I realize that I have consigned myself to daily water changes until the new tank stabilizes. <If you're referring to the 15G, you might be surprised. A cycled filter and some established gravel will speed things up tremendously> I have test kits for ammonia, nitrates, nitrites and pH in the mid-range. <Very good. Use these to determine the frequency of your water changes. Excessive water changes can inhibit cycling rather than promote it> I'm concerned about putting three mollies into a newly set-up tank, even with filter media, plants <Your plants may not do well with salt. Hold off on transferring these> and gravel from the old. What will I have to do to make this feasible or, should I simply put the mollies into the (currently understocked) 35 gallon until the new tank is set up for a few days, at least? I dislike the idea of moving them too much..... <Best case? You'd have the 15G set up for a couple of days. As you've surmised, though, moving them is more stressful. Given your current parameters, I'd be inclined to move them, once, to the smaller tank and watch them and your water conditions closely for a few days> Any and all thoughts welcome! <Best of luck, Vicky. Tom>

Keeping mollies in Saltwater 3/19/06 Hello, <Hi, Pufferpunk here> I was wondering what mollies could be kept in full salt water. <Yes they can. You must acclimate them slowly or start them in freshwater & raise the specific gravity no more than .002/week.> Can you keep figure 8 puffers in full salt water? <F8 puffers are best kept in low-end brackish water, of a SG around 1.005. See: http://www.thepufferforum.com/articles/puffer/f8puffer.html > What about feeder guppies? <Guppies are freshwater fish. HTH ~PP> Thanks for the help.

Molly in brackish water--Bob Fenner 3/15/06 Hi Bob Fenner, I have had conflicting info about Molly's in brackish water. I heard that Molly's need a little salt, and/or they need brackish water. <Mmm, there are some species, geographical races of Mollienesia that live in "all freshwater"... that is hard, alkaline in nature... Most live in water naturally with appreciable salt content. All tolerate some...> I had a molly that was doing quite well for a while (5-6 months) in a (29g) tank that had little or no salt. Then about 3 weeks ago, it began to be sluggish and less active. Hiding in the plants, trouble swimming etc. It was still eating and there were no signs of disease. An employee whom I trust at the local fish store said it needed to live in brackish waters, so I brought it back in to give it a better home. Different people at the LFS were working when I came back, and they seemed to disagree about the brackish deal. What do you say? Thanks. --Missing my Molly <Mmm, there is a very nice piece... a "stand" if you will re Mollies and their affinity for salt in this month's Tropical Fish Hobbyist Magazine (the one touting the upcoming Livebearer Association Conference)... Much of "the story" presented there. Bob Fenner, who will get around to writing review pieces on the common poeciliids... unless others send in, sell to CA... for posting> Balloon molly w/ ich... env. dis. 3/14/06 Hello, I have a 10g tank and had two guppies and 3 balloon mollies. After the first day one of the guppies died. About four days after that the other one died. Then a couple of days later one of the mollies died. Then I noticed that there were white spots on the last two mollies and found out that it was ich. I bought some cure-ich and have been treating the tank/ fish for two days (2 tsps) so far. Tonight another molly died and I thought it would because it kept staying up at the top & never really did much else. The last molly seems to be ok and is floating around like normal but still has spots. I read that I could put salt into the tank and so I put about 2 tsps so far. My question is, can this poor littler loner make it? Will he survive alone until this ich is gone, and when should I get more fish? We have well water, but I put in AquaSafe drops and stress coat before I added the fish to the tank. I have had this tank about 2 1/2 weeks. What can I do to prevent ich in future? Thanks, L. Friend <... your system is not "cycled"... and this is likely the root cause (along with the medicine poisoning) for your ongoing troubles... Please read here: http://wetwebmedia.com/FWSubWebIndex/fwestcycling.htm and the linked files above. Bob Fenner>

Molly trouble? Uncycled system, aggression - 2/4/2006 Hi Guys, great site! I found your website while Googling on aggressive mollies, you see, the problem I have is this..... I just set up a 10g tank, my first. I asked the staff at my local pet shop what would be a good fish to start off with, and they recommended two mollies, since they are good communal fish, but get lonely on their own. <This system was/is cycled?> However, I had been doing some reading on cycling an aquarium, and decided to put only one molly in to start the cycle, so I bought one Dalmatian Molly. After a few days, I tested the water for ammonia and nitrate/nitrite, and everything was fine, <Takes a few weeks...> so I decided to add another Molly to keep the other one company. I bought a Leopard Molly, which is slightly larger. I realize now the cycle takes a bit longer than 3 days, but at the time I didn't and I wanted the Dalmatian to be happy. At first the Dalmatian Molly was happy swimming around with his new friend, but the next day, the Dalmatian Molly was chasing around the Leopard Molly. The poor guy cant get any peace, every time the Leopard Molly stops, the Dalmatian Molly swims rapidly towards him. It looks like he's trying to nip him. The attacks seem mostly to come from behind, but attacks from the side, above and below aren't uncommon either. I'm unsure whether they are male or female, but I'm pretty certain they are the same gender. Is this normal behaviour for Mollies, or is the Dalmatian just a bully? <Can be normal... but having them in small odd numbers, larger tanks generally alleviates> Id hate for the Leopard Molly to die of stress. I keep my tank at about 75 (although I've noticed this can fluctuate upwards to almost 80 when the light is on), <Too much diurnal flux...> with a little bit of salt and plenty of hiding places. Thanks Russell Gold <Likely all will be well here in a few weeks. Be careful re feeding, perhaps catch the bully and keep it in a net up in the corner of the tank for a few hours... this often works to reduce aggression. Bob Fenner>

Re: Molly Help 1/31/06 Hello- so, apparently I should have done my own research before (key word) buying Mollies. I have a junior 1 gallon fish tank on my desk at work. <Too small for this/these species> I went to our local Wal-Mart and asked the sales lady what fish and how many would do good for a very small tank for my desk. After her suggestions (which she says she has two large tanks, so I assumed she had some knowledge about fish) <The usual admonition here to be careful re such assumptions> I bought 4 shrimp and 5 mollies... <... way too much, too soon> I THOUGHT this was two many, but she said no, no.... I didn't think about the breeding factor and one or more could already be pregnant.. well, within a week 3 shrimp died, and one molly. so, I changed the water in the tank on Saturday, <"The" water... as in all of it? Not a good idea...> (now have 4 mollies only) and on Tuesday I found 5 babies... I wonder if maybe I washed them out (IF that are tiny and I couldn't see them???) anyway, I have taken them out when I found them.. and another lady at work bought the same type of tank for just the babies... then another lady took two of the adults for her 55 gallon tank at home... .Question... is two mollies still two much for the tank... one is a junior (a lot smaller than the other.) should I return them for another type that would be better suited for my tiny tank?? <If it were me, mine, yes. I would seek out life that is much more "hardened" genetically for the travails of life in such a container... Perhaps a male Betta, some Whiteclouds... or a Paradisefish... Bob Fenner> Sincerely, Wished I had researched myself FIRST... <Me too my friend>

Can I Control It? Birth Control for Mollies 12/5/05 Can you please give me some suggestions for choices of fish that will eat sailfin molly fry? I have a 58 gallon planted tank & will soon be overrun with mollies. The only other fish in the tank at the moment are 3 Siamese algae eaters, 1 Oto & Nerite snails. <If I could make molly birth control, I could become rich. Mollies are pretty hardy fish, but they do like brackish water. I don't think your Siamese algae eaters and especially your Oto would appreciate the salt. If you go brackish, you could go with knight gobies. Many larger fish will love the chance to go after molly fry. Depending on how hard and salty your water is you might consider various barbs, loaches, some of the freshwater minnow sharks, or gouramis. Check www.liveaquaria.com for some quick comparisons. Their information tends to be accurate in terms of tank size and conditions.> Thanks, Kim <Please don't hesitate to ask follow up questions -- I know I gave a broad answer. Catherine>

Re: controlling sailfin molly population 12/13/05 Hi, thanks so much for the answer. I don't think I will go brackish because the mollies really seem fine. My water is hard & alkaline. KH=9; pH=8 before CO2 injection & 6.6-7.0 with CO2. I want to get a school of something that would be the focus of my aquarium - eating the fry would just be a bonus. How many male gouramis can I have together in a 58 gallon tank? I read they may be aggressive with each other. <I have a pair of blue three spot gouramis and a female lace gourami in my 29 gallon. The lace gourami is the boss. Gouramis can be really nasty. You may only be able to have one male and several females; you may be able to have 3 or 4 pairs. However, I must say my gouramis are extremely disappointing. They like hiding in the back behind the plants. Some gouramis are much more friendly.> I was also considering Boesemann's rainbows or neon blue dwarf rainbows. Any suggestions? <Both seem to be good choices. You can get a nicer school of the neon blue dwarf rainbows. You also might think about some of the dwarf gouramis, but they can be fragile; sometimes dying for no apparent reason. The Boesemann's rainbows can be a bit aggressive, so I'd start with a few and then keep adding.> Thanks, Kim <Catherine>

Great FAQ page for Mollies 11/17/05 Hi Bob, I just wanted to say how great it is that you take the time to answer so many inquiries. <Is spiffy, though I do wish I were more organized, disciplined and would cut off my input in this way, re-direct my efforts toward generating articles more, sponsorships...> We're just starting our first fish tank. It began with our sons winning fish from their school's Fall Festival. We went to our local mega-store and bought an inexpensive 1 gal. tank and some water conditioner. However, those fish only lasted a day. But It did get us to run out to our local (San Diego) PetSmart and let our sons each pick out a new "healthy" fish. They chose the Balloon Belly Mollies. We have 1 orange w/ black speckles, and 1 Black (by reading some of the info on your web site - I am sure this is the female). They are only in a 1 gal. tank. (remember, our first tank was only due to "fair" fish. - so we didn't bother investing much money.) But we love our Balloon Belly Mollies! I could just sit and watch them for hours, they seem so happy and they have so much personality. I found your site, because one of the Mollies is developing some tiny white spots, so I went on-line to find some answers - and I did. I now realize that they need more than a 1 gal. tank, and better water treatment, so I will probably get a new 10 gal. tank. <Good> My concern is just getting the 10 gal. tank set up properly from the beginning. <I see... best to move all the existing water, decor... into the new tank> Thanks to your web-site's faq page (WetWebMedia - in case you have several). I have plenty of good info on care for our new Mollies. <Great> I will be searching for info about the best possible set-op for Balloon Belly Mollies in a 10 gal tank, but if you have any extra special tips - I'd appreciate it. <Mmm, all we have (to date) is posted, indexed> Thanks for maintaining such a great website. Eric - San Diego <Bob Fenner... also in San Diego>

Molly Behaviour, pH and Alkalinity - 10/27/2005 Hi there. <Ahoy.> We have 4 Dalmatian mollies 3 female and 1 male. They are in a 55 gallon tank. We have had them for a week and a half now. The male has seemed to claim the heater as his. He will chase off the females if they get to close to it. <I have seen territorial behaviour in mollies before. Usually males are more aggressive with other males than with females, though.> The temp in there tank stays 80. The first 3 days or so the male bugged the females all the time. Now he doesn't seem to chase them to breed any more. He eats and will come away from the heater for a little. <Probably a good idea to keep a close eye on him, just in case.> One of the females which I think is pregnant was claiming that same corner yesterday and ran the others off. <Typical of a pregnant fish to chase others away from "her spot". I would still observe these fish very, very closely for a while, in case there is something pathogenic at play.> I just did all the test and here are the results nitrite is 0,nitrate 0,amonia .25 ppm., alkalinity 120 ppm., pH is below 7.0. <Better for this to be higher for mollies.> I am not sure how to keep the pH and the alkalinity balanced. I have pH Increaser should I use this? <Mm, instead, I would add a small amount of crushed coral or aragonite sand in a filter bag in your filter. This will help quite a bit. Start with just a little bit, though, and increase slowly over some days - test your pH regularly as you do this so you don't let it increase too much too quickly.> We have not done any water changes since we set it up. <Probably a good idea to start.> Thank you Katina <Wishing you well, -Sabrina>

Oh Golly Mollies, Salt, pH, etc. - 10/21/2005 Hello I am new to salty systems. I've always had freshwater aquariums which I still run two. But I saw some Dalmatian Mollies and had to get some. I have one male and three females. I do plan on adding maybe two or three more mollies and an algae eater and that's all this tank will have in it. I don't want to overcrowd them. I talked to three different fish stores to set up my system to get it ready. (I wish I had found this site first.) So I set up a 29 gallon tank with one teaspoon of salt per 5 gallons of water. Should more salt be added? <Nah. Especially not if you plan on an animal for consuming algae. With salt in the water, I would recommend using Caridina japonica, the "algae-eating" shrimp, as these fare well in slightly salty conditions.> I have an Aqua Tech 20-40 power filter at a flow rate of 160 Gph with bio fiber. Is this ok or would a bio wheel be better? <Mm, whatever you prefer. If you've already got the Aqua Tech, I see no reason to buy something different.> All the stores said a pH of 7.2 was right; mine's between 7.4 and 7.8. <This is fine - BUT - please don't let it be *fluctuating* between these.... far too much fluctuation between 7.4 and 7.8 to be safe. A steady pH is pretty important.> The temp is at 80 degrees. I see on you're site you recommend a high pH so should I get some crushed coral sand to raise it, or is it okay at the level I have? <Constant, steady pH is better than precise pH. You'll be fine with what you've got, I think.> Also I do test the water with strips but this just shows a range of where it should be. So should I get a better testing kit if so what do you recommend? <I would. Look for a quality liquid-reagent test kit.... Kordon makes 'em, so does Aquarium Pharmaceuticals.... You'll need pH, ammonia, nitrite, and nitrate most essentially.> Thank you for your time. -David <Wishing you well, -Sabrina>

Fishbowls and mollies 9/27/05 Hello! My son has recently won a black molly fish from his teacher at school. We have Swimmy in a fish bowl at home, with just tap water. <Have you treated your tap water with a dechlorinator? Do you have a heater, gravel, a filter? Without these, your fish is likely to become stressed and ill. They are tropical fish and prefer water about 78F.> Knowing that mollies are schooling fish, I would like to get one more. <If your molly is male, you'll want two females, but remember, they are live bearers and you'll have many, many fry.> Can I keep both of them in just a fish bowl? Or is a more elaborate set up necessary? <No, even a single molly needs to be in at least 10 gallons and 30 gallons is preferable. They do need an "elaborate" set up with a heater and a filter. Look around WWM for more information on setting up a fish tank and keeping livebearers.> Thanks, Julie <Good luck, Catherine>

FW fish... environmental induced incompatibility 9/21/05 <Adam J here with you this evening.> Hi, I have a one gallon aquarium and got two lyretail mollies for it. <Far too many fish for this sized set-up.> I do not know how to determine the sex but one is silvery/white and the other is black. <Males have a more prominent dorsal fin in comparison to females as well as a gonopodium. (modified anal fin on the underside of the belly)> also have three florescent zebra fish. <Not more fish'¦> I am unsure of their real name <They sound like genetically modified Zebra Danios a.k.a. Glofish, many hobbyists reject them as impure, see here for detail http://www.wetwebmedia.com/ca/volume_2/cav2i3/glofish/Glofish.htm> but they are very small. The silvery lyretail keeps attacks the black one and I do not know why. <Likely that the crowded conditions are responsible for the aggression.> Can you help? <I would immediately do one of the following a.) return the fish to the LFS or b.) immediately upgrade tank size (10-15 gallons)> <Adam J> Salt for mollies... and everybody else? 7/7/05 Hey, Okay, this may sound like the dumbest question in the world, but is it okay to put salt in an aquarium with black mollies in it. I recently received a 10 gallon fish tank for my birthday, and I am not experienced with fish care. Can you help me? <If the other life there can tolerate salt, sure... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/mollysysfaqs.htm FishMan001> Catlady2460 Balloon molly We recently introduced 2 balloon mollies into my daughter's 10 gallon tank. <Hello, this is Jorie. Couple of questions...how many other fish were in the tank and how long had the tank been setup? I'm trying to determine if too many fish were added too quickly, causing a buildup of toxins like ammonia, nitrite and/or nitrate, all which are poisonous to fish.> The male died about 2 weeks after we bought them and the female seems to be fine. <What kind of water change schedule do you have this tank on? Hopefully you are changing around 50% every week (just a rough guestimate without knowing what all you have in the tank) to keep the water clean and toxin-free.> My question is, we have guppies in her tank and the female balloon molly bites the tail off the other fish. Is this normal, and if not what should be do? <I keep balloon mollies, too, and I've seen some of them be quite aggressive sometimes. It seems to really depend on the individual fish. If this behavior continues, you will have to separate the two types of fish - perhaps keep the 10 gal. a "guppies only" tank, and invest in a bigger tank for the mollies? Another thought: is there sufficient cover (i.e., hiding places) in the 10 gal.? Perhaps the molly felt too "out in the open"?> For now, we have put the balloon molly in the tank that my son has that has swords, platies and guppies, but at least the are bigger fish. <This is a fine combination, so long as you haven't overstocked your son's tank. How big is that one and how many of each fish are in it?> Please let me know what we can do the fix this problem. <Hope I've helped...Jorie>

Gold Dust Mollies A few weeks ago I bought some gold dust mollies from the pet store...and for a while they were doing fine. I had 1 male and 4 females. <Hi Sam, this is Jorie. Couple of questions...how big is the tank you introduced the fish to and how many other fish were in it? Was the tank newly setup or had it cycled?> I added some proper ph 6.7 to the tank and within 24 hours I had 2 gold dust baby mollies which I put in a separate breeder container in the same tank and they have been doing fine for a week. <I'm not sure what type of fish you have, but am curious as to why you added the "Proper pH 6.7" to the tank. What was the pH reading prior to adding this? In general, I think the less additives you introduce to the water the better (with exceptions on a case by case basis, of course). It is generally much more important to keep the water's pH stable than to exactly match what the fish textbooks say are optimum conditions for a particular breed of fish. Again, depending on what all type of fish you have we can settle on a happy middle ground.> In the meantime I have lost two of my mollies.. one female and one male gold dust molly. so the past few days I have been doing a 30 percent water change and I am also using crystal clear once a day starting today. <Sorry to hear you lost the fish. Water changes are absolutely the best thing. Do you have any sort of water test kit? If so, have you tested for ammonia, nitrite and nitrate? My hunch is that you perhaps added too many fish too quickly, and the toxins produced by the fish waste added up to quickly. I'm not sure what the product "Crystal Clear" is, but with regular water changes, good filtration and general good husbandry I would suspect it isn't necessary. Are you using regular tap water to fill the tank or something else? Tap water should be fine, just be sure to use a product like "ChlorOut" to remove the chlorine. Or, in the alternative, you can use de-ionized or reverse-osmosis filtered water (chlorine would be removed through the filtration process). Just stay away from bottled water, as that lacks many essential elements fish need for optimum health.> In my 10 gallon tank I have the following fish...4 blue danios.. 3 blind cave fish, one common Plecos algae eater. and the 3 female adult gold dust mollies left along with the two babies.. <Whoa, Nelly! That's a lot of fish for a relatively small tank, my friend! Blue danios reach around 4" when they are fully grown, and I personally think they should be kept in nothing smaller than a 29 gal. aquarium. As for the Pleco, that "little" critter will eventually become 12-18" long - def. too big for your tank!! I think 3 female mollies and 1 male in your 10 gal. would be perfect...I'm hoping you have somewhere else to house the other fish, or friends/family/pet store who can take the others? I definitely think you lost your mollies due to poor water conditions...way too many fish producing lots and lots of waste.> Please tell me I am doing the right thing with the 30 percent water change on a daily basis for 21 days? <You are definitely doing a good thing with the water changes. Do invest in a test kit to measure ammonia, nitrite and nitrates (all should be at zero; these are listed in decreasing order of toxicity to fish) Once you get these levels under control, I'd suggest a schedule of 50% water changes twice per week if you are planning to keep all the fish you have now (which I do not recommend). Sam Las Vegas.. <Hope I helped, Sam. Please do consider lightening your fish load as soon as possible. Jorie>

re: Gold Dust Mollies Click on this link to view a digital photo I took of my fishtank which is a ten gallon tank. You can see how clean it is. And how happy they all seem to look. Even my Pleco. Sam re: Gold Dust Mollies http://groups.msn.com/BowmanCompany/veriousotherphotos.msnw?action=ShowPhoto&PhotoID=334 <Thanks for sharing. Don>

Re: Gold Dust Mollies You have answered all of my questions.. also thank you for letting me know about not using the bottled water for one of my kids in his tank has been using bottled water. He will be happy to know this is not good but to use tap water which I have been doing.. I have also learned in the past year and a half that I need to make the tap water coming out of the sink the same temperature as the tank. <Yes, this is a good idea. You don't want to shock the fishes' systems.> I lost a lot of fish when I first started with changing the water etc.. and also I will do a 50 % water change twice a week...that will make my life easier... <Twice per week is just my best guess; really, you need to invest in a test kit to measure at a minimum ammonia, nitrite and nitrates (ideally all should be at zero). Once you've been taking water measurements long enough, changing filter media, etc. long enough, you'll get a regular schedule that works best for your tanks!> Plus I have a decent water filter pump with a sponge and with charcoal so it helps in keeping the water clear.. I am going to try and keep them all together for they seem to be recovering well... <Just keep in mind that mollies are very messy fish...you need to "pick up" after them (i.e., suction out their poop!) pretty regularly!> ...the two baby gold dust mollies are doing just fine now on week two. <Great news...hope they grow to be big and strong!> I also feed my algae fish those algae tablets that you just drop into the bottom of the tank.. he seems to like them as well as the mollies for some unknown reason.. <Mollies are omnivores and do appreciate some veggies in their diets.> ...but they are all doing well since I have been doing the water change.. and when I have some extra money .. I will get that "ChlorOut" <It isn't very expensive at all. Keep in mind this isn't a luxury item, but a necessity...chlorine is not good at all for fish!> Thank you. so much for taking time to read my e-mail and giving me the answers I needed. again thanks a bunch Sam Las Vegas, NV <I'm very glad to have helped, Sam. Best of luck to you and yours, Jorie.>

Black Molly Tank Hello. I really find your site very informative. <Great...me too! I'm always learning new things from WWM!> Tank info- I currently have a 10 gallon tank only inhabited by mollies (4F-2M). They have been in the tank for 2 weeks with no apparent diseases. Tank registers w/trace amounts of ammonia & nitrites for which I've added something called "CYCLE" & subsequently "AMQUEL+" which now prohibits me from testing with my current kit because readings will be false. <OK, what's done is done, but I do not recommend adding products to attempt to rid the water of harmful toxins such as ammonia, nitrites and/or nitrates. Truly the only safe way to improve water condition is to do water changes. I would suggest you do a large (75% water change) ASAP and stop using the additives you've mentioned. (Note: The only additive you will need is something to remove chlorine if you are using straight tap water...not sure if that's what Amquel+ is for - I've always used a product called ChlorOut. Just look for the term "dechlorinator").> The ph is 7.4-7.6 & the water is hard. I initially used bottled water to start-up the tank & until just recently started using tap water for water changes, prior water changes were w/bottled water. <Bottled water is missing essential elements that fish need, so it's good that you switched to tap water. Again, do use a dechlorinator to remove chlorine from the water, but that's about all you should need. If you plan on keeping a molly only tank, your fish would probably also appreciate a bit of aquarium salt...mollies can actually live in full saltwater, but bringing the salinity up to just 1.002 or 1.003 will drastically improve their health in many cases.> Temp=80 deg & there is 1tbls of aquarium salt per gal. <Ah ha! You've already done the salt-thing! Good deal. I don't like measuring by teaspoons, though; I would suggest you invest in a plastic box-type hydrometer to measure salinity. They are relatively inexpensive ($5-7) and readily available. Also, I'd consider dropping the temp. down a few degrees...80 is pretty warm for mollies.> Problems---I don't really find the fish up to par. They don't appear as active as they should be & at times when I check on them in the morning I find 1-2 of them resting on the tank bottom but when I put on the light all come to the top in search of food. <I think once you drop the temp. a little and rid the water of all the toxins, your fish will perk right up. Solutions such as "Cycle" really promote a false sense of security, in my opinion, and you are much better off without them, but keeping up with regular water changes in place. Mollies are messy fish, so I'd suggest doing 50% water changes 2x per week, once the tank is fully cycled. Also, consider adding on a supplemental sponge filter or two to help control the water parameters.> And here's the strange problem-No females appear to be pregnant! The males are larger, I don't know if this means anything. <Give them time, it will happen (far too frequently). If there are toxins in the water, this may be inhibiting their desire to breed. Also the majority seem to have clamped fins most of the time although there is one dominating F who is never clamped. <Sounds like a water quality issue to me.> Your response & help are most appreciated. As I am new to this how will I know if/when you respond? Will I have to check the site or will you let me know in another form? <I'm sending this e-mail back to you, but it will also be posted in the Daily FAQ's> I've also set up a new 20 gallon tank, just started running yesterday (w/no fish yet) & as I have not put any chemicals or treatments in it, if you have the time, I'd appreciate any input you might have as to start up an exclusive Molly tank. <Sounds like you are headed in the right direction, but just substitute regular water changes for the chemicals you mentioned before. Once your 10 gal. is completely cycled (meaning ammonia, nitrite and nitrate all read "zero" on the test kit you have), I'd suggest taking 50% of the water out of that tank and putting it into the new tank. Also, you many want to invest in some bioballs, through them in the 10 gal., then in maybe a month or so (once everything is fully cycled and stable in the smaller tank), move them to the larger tank. This will help "kick start" your new cycle in the 20 gal. Then, start slowly by adding one or two mollies to the new tank, and check the water's parameters very regularly. I'd suggest you pick up a book by a fellow named David E. Boruchowitz called "The Simple Guide to Freshwater Aquariums"...it very nicely spells out the basics in a user-friendly format, in my opinion. (Note: don't take his advice on livestock stocking as the gospel, though, as he tends to put too many fish in too small of tanks, in my opinion. Otherwise, I like the book very much and even started my own first aquarium with its help!) Thanks so much for your time--Ric V--- <Hope I helped. Let me know if you have any follow up questions, Ric, and good luck! Jorie>

Mollies and banjos Hi guys, First of all I really love your site, I have learned so much. Anyway, to my question, I have a 55 gallon setup with 7 mollies (not sure of sexes but I asked for mostly females), 2 banjo cats, and 1 Cory cat. The tank is pure FW right now and the mollies don't seem to want to breed. I have read on the site that adding salt, raising the pH, and keeping the temp. around 80 would get them going. I know the Cory would be ok but I am worried about my banjo's, I read that they like a lower than 7 pH, I love the little guys and I don't really wanna get rid of them. Would having the pH around 7.8 hurt them? What about the salt? I would love for my mollies to start having fry. Any help would be appreciated. <Hi Jason, Jorie here. How long have you had this setup? My guess is that as long as you indeed have some mixture of males and female mollies, they are breeding, and the fry are simply being eaten. Happens all the time. Couple of things you can do to try and save the babies: provide lots of plant cover, esp. floating plants (either fake or real...not sure what your tank is like), set up a separate birthing tank and QT one or two of the females for a while, until you see fry. Unless you are a serious hard-core fish breeder, I wouldn't suggest monkeying around with the pH, temp., etc. I've got a 44 gal. community FW tank that includes mollies and I keep it at 78 degrees, pH of around 7.5, pure FW, no salt, and these guys are *constantly* having babies! Nothing can stop them, it seems! You could add a bit of aquarium salt as per the container's directions, as that would only help improve the overall health of everybody in there. Just be patient and make sure to provide lots of hiding places for the fry...my hunch is you just aren't seeing the babies, but they are indeed being born!> Thanks, Jason Young <You're welcome. Jorie>

Mollies Hi, I have questions about mollies. I have trouble with them in my community tank. I see them being uncomfortable and try to increase the salt in the water but they keep looking uncomfortable. They keep "shimmying" or wagging back and forth as if they are feeling ill. <Good description... "Shimmy" is actually a name for a common symptom/disease of these livebearers in captivity> The ph level is good, around 6.8 to 7.0. <Actually, no... this is too low for mollies. Maybe take a look on fishbase.org re this genus... these marine fishes actually live in water of marine pH... the upper sevens, low eights... and the pH scale, like that for earthquakes, is a base ten logarithm... http://www.fishbase.org/NomenClature/ScientificNameSearchList.cfm?Crit1_FieldName=SYNONYMS.SynGenus&Crit1_FieldType=CHAR&Crit1_Operator=EQUAL&Crit1 _Value=mollienesia&Crit2_FieldName=SYNONYMS.SynSpecies&Crit2_FieldType=CHAR&Crit2_ Operator=contains&Crit2_Value=&group=summary&backstep=-2> I used to have a kit to test hardness and ammonia levels but one of my dogs got hold of it and managed to eat most of it before I found it! <... do be CAREFUL with these test kits... some have reagents that are quite toxic... Keep Out of Reach of Children... and PETS> But I keep ammonia eliminating crystals in my filter system. I just put two in about 2 weeks ago. Even after I had just put them in, the mollies were still shimmying or wagging while the other fish all seem to be healthy and were swimming normally. Is there something else I should be doing or can try doing to see if they get well? I would appreciate any information you can give me. Thank you very much! Sincerely, Leslie C. Wilson <Mollienesia (the scientific genus name for mollies) are VERY often lost in captivity due to this very common lack of understanding of their environmental needs... as stated, most are actually saltwater species... and your other livestock... may NOT tolerate salt... Spend some time researching what you have currently, and make a decision (as in "nothing is decided till it's done") about what sort of system you want... with the mollies, hard, alkaline, salty water... and life that likes, tolerates this.... or.... Bob Fenner>

Molly help! (or, Someone Forgot to Move this One) de Bob Hello! I have 3 adult mollies (one black, one silver, and one Dalmatian) and 5 baby mollies (don't know what color!). I have a few questions for you, and hopefully you can answer them all! 1) My Dalmatian molly keeps chasing my silver molly around and 'tags' her sometimes. I have had the black [male] molly and the silver [female] molly for some time now, 5 or 6 months I guess, so I didn't think that the Dalmatian molly would be 'territorial' because I just got her 2 days ago! Why do you think the chasing occurs?? <Mmm, mainly reproductive behavior> 2) My silver molly has developed the shimmers since I brought the Dalmatian molly home and introduced them. Is she scared of the newbie?? <Good observation/description... maybe... perhaps has "caught something".> 3) My black molly is quite a bit smaller than the other mollies and has developed a white/grayish stripe on his 'neck' from gill to gill. What do you think this could be?? I am worried about him, he is the 'runt'!! <Ah... that "something" alluded to above... there are infectious and parasitic diseases of mollies in particular amongst livebearing fishes... One of the reasons for quarantining new livestock... using salt/s with them> 4) Is it really necessary to add aquarium salt to the tank? 5) Is it ok to feed the adults FirstBites fish food? <Yes to both> 6) One of my females gave birth to the 5 babies (which I have carefully separated from the adults), is it 'normal' or ok for there to be so few? <Numbers vary, yes> I heard that mollies can have up to 80 fry, so I naturally became concerned. I haven't seen any other babies in the tank. <Larger fish, more established/well-fed... more babies> 7) How can you tell when a female molly has just had babies? Are there any signs? <Mmm, yes... their vent area will be clear... the female far more active...> Well, I guess I'm out of questions for now. If I have any other questions, I may email you again! Thank you very much for taking the time out of your busy day to 'hear me out'!! ~Anissa from Rockwall, Texas <Glad to offer you our input. Unfortunately we don't have actual articles re Mollienesia (as yet), but do have an accumulation of input that we've archived here: http://www.wetwebmedia.com/FWSubWebIndex/mollyfaqs.htm and the Related files (linked above), that you may find useful. Bob Fenner>

Molly help! Hello! <Hi...this is Jorie> I have 3 adult mollies (one black, one silver, and one Dalmatian) and 5 baby mollies (don't know what color!). I have a few questions for you, and hopefully you can answer them all! <I will try...> 1) My Dalmatian molly keeps chasing my silver molly around and 'tags' her sometimes. I have had the black [male] molly and the silver [female] molly for some time now, 5 or 6 months I guess, so I didn't think that the Dalmatian molly would be 'territorial' because I just got her 2 days ago! Why do you think the chasing occurs?? <Male mollies can be quite aggressive towards females (and even other males at times)...you should try to keep a 1:4 or even 1:5 ratio of males: females, if possible (i.e., if your tank size will allow). Otherwise, it has been my experience that the dominant (alpha) male will terrorize the female(s). How big is your tank? If you've got a 20 or bigger, perhaps consider adding more girl mollies to the mix?> 2) My silver molly has developed the shimmers since I brought the Dalmatian molly home and introduced them. Is she scared of the newbie?? <I'm not quite sure what you are describing here...is she visibly shaking? If so, that sounds to be a potential health issue. Have you tested the water chemistry lately? Ammonia, nitrite and nitrate measurements? Is this an established tank (has it completed the nitrogen cycle)? If you aren't familiar with what I'm talking about, please refer to some of the wonderful articles available on the site that discuss "newbie" issues such as these; also, I like to recommend a book that's great for beginners called "The Simple Guide to Freshwater Aquariums", by David Boruchowitz. Another factor is how much cover do you have in the tank? Fake and/or live plants, as well as decorations are great for allowing fish hiding places, and will also help with your problem described in #1 above.> 3) My black molly is quite a bit smaller than the other mollies and has developed a white/grayish stripe on his 'neck' from gill to gill. What do you think this could be?? I am worried about him, he is the 'runt'!! <I too keep black mollies, and I've noticed that their gill area tends to be more noticeable than the other colored mollies' is...so long as he is breathing normally and not acting strange, I think this is just how the coloration of the black molly plays out. I was concerned when I first noticed this, but have been watching closely for many months now, and I've not seen any problems as a result. I think it's purely cosmetic.> 4) Is it really necessary to add aquarium salt to the tank? <Not a "do-or-die" thing, but will definitely be appreciated by the mollies. Aquarium salt will reduce the outbreaks of ich and other diseases. Some mollies are more fragile than others, depending on how genetically manipulated they have become (the chocolate lyretails, for instance, are particularly fragile, as I understand). I've got a batch of mollies that I planned on keeping in a freshwater community tank (no salt at all), but in reality, they kept getting ich; each time, I'd treat with hyposalinity (increasing the level of salt) in a hospital tank, only to have them succumb again once back in the FW. I've since put this batch in its own brackish tank (salinity around 1.005) and everybody is quite happy. I've got one particularly strong adult balloon male who lives in the FW tank with no problems, but long story short, if at all possibly, I do recommend salt. Do you keep your mollies with other fish? If not, you can go ahead and salt the tank according to the manufacturer's recommendation; if yes, do read up on whether or not the other inhabitants can tolerate salt, as some fish absolutely cannot.> 5) Is it ok to feed the adults FirstBites fish food? <To the best of my knowledge, that's the powdered fry food? That won't be enough nutrition for the adult molly; I've usually begun feeding my fry Hikari's Micro Pellets (step up in size from fry food) by the time they are around 9 mos. or so...I'd definitely suggest purchasing small pellets, such as the ones sold by Hikari or New Life/Spectrum (both are excellent quality) for the adults. Also, they'd certainly appreciate some frozen or freeze-dried bloodworms and Mysid shrimp every once in a while...variety for fish food is great, and they'll be very grateful to you!> 6) One of my females gave birth to the 5 babies (which I have carefully separated from the adults), is it 'normal' or ok for there to be so few? I heard that mollies can have up to 80 fry, so I naturally became concerned. I haven't seen any other babies in the tank. <A female's first few batches of fry can be very small...as she grows, so will the amount of fry she produces! Don't worry, soon enough, there will be more than you can handle, and you'll be looking for homes for them!> 7) How can you tell when a female molly has just had babies? Are there any signs? <Well, there will be teeny little fry swimming around the tank! Best way is to identify which girl is pregnant, and observe her behavior...she'll likely go and hide while giving birth (again, make sure there's enough cover in the tank to allow for this...see response to #2 above), and emerge with a smaller mid-section...> Well, I guess I'm out of questions for now. If I have any other questions, I may email you again! Thank you very much for taking the time out of your busy day to hear me out'!! ~Anissa from Rockwall, Texas <Hope I've helped, Anissa! Jorie>

Ammonia in Fry Tank I have found your website to be very helpful. First I want to say that I am a proud owner of two mollies one a balloon black (female) and the other a orange (male). Two days ago I discovered 17 fry. I was so thrilled! I need help in deciding what to do. So far the adults have left to fry alone. No problems there. I have a 2.5 gallon tank and know that that is not enough room for all of them. I am wondering if I should take the adults out (to another 2.5 tank) and leave the fry to grow a bit bigger in the existing tank. I would like to possibly keep two at the most but want them to get bigger so I can determine the sex. I have spoken to the LFS and they will take a the rest from me. My levels are at ph. 7.8 nitrite .25 nitrate 5.0 and ammonia is at 4.0. temp is 78/80. I am a determined new aquarist. What is the safest thing to do in my situation? Thanks in advance. Vanessa I. Tucker <Water changes, and lots of them. 4.0 ammonia is deadly! And .25 nitrite is .25 too high and it's about to go higher. Check the pH of your tap water. If they are within 2 or 3 tenths then match temp, dechlorinate and change 50% right now. Wait a few hours and do it again. Then daily until ammonia and nitrite are at zero. Your problem is a lack of bio filtration, something that takes time to get established. Do move the adults out. The ammonia is from fish waste. The less fish, the less ammonia will be added to the tank. Read here on establishing FW bio filtration. http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm I hate to tell you to limit feeding the fry, food is very important to growing fish. But the more you feed the more waste will be produced. Just feed them twice a day and only enough that it's all eaten within a minute or two. Once the ammonia comes down you can up this to three or four small feedings a day. When you do the water changes use a gravel vac to get any uneaten food and old waste out of the system. You are going to have to continue with almost daily water changes for a month to six weeks. It will take about that long to get cycled. That link contains the most important information a new aquarist needs to have in order to keep their fish alive. And congrats on the births. 17 is a lot for a Molly. BTW they are not as bad as guppies and swordtails when it come to taking their young. As long as they do not get too hungry they generally leave them alone. But since you need to limit feeding, move the adults out. Don>

Chocolate Salty Mollies.. >I have been reading your Molly FAQ's. Regarding adding salt to the Molly tank---- 1-- How much salt per gallon? >>You'll want to measure with a hydrometer, I prefer a lab grade float for accuracy and decent price. Mollies can "swing both ways" - this means they can go from completely fresh water to completely marine environs. >2-- Is regular noniodized table salt OK. >>I wouldn't, I would use a sea salt mix. The utility of non-iodized salts for the table is purely for medicinal/prophylactic treatments. Also, don't make the mistake I did the first time I swung some mollies to salt - I did it too fast (in just a few hours) and one "popped" (looked like a pine cone, then shimmied, shook, and died. Boy did I feel AWFUL!). >Thanks! Rick >>You're welcome. Marina

Water Flow and Mollies I have read THOUSANDS of pages and researched everything I possibly can and have yet to find answers to the following questions. I am sure it's out there somewhere, but it is probably the last page on the internet. I have a 72 gallon freshwater aquarium with mollies, a few guppies and Gouramis. <A bit of a strange mix because of the aggressive tendencies of the Gouramis.> I have a Fluval 404, a Fluval 204 and a Magnum Pro with the 2 BioWheels going. I have 5 albino mollies that don't seem all that happy. They don't seem sick necessarily either. I think it has something to do with the water flow. I try to adjust the outflows so that the water hits the front corners of the tank and arcs down towards the center. This seemed to make them happy but I am not so sure any more. How should I direct the water flow for my tank? <I would do as you have described above.> Above the water line with lots of agitation? Below the water line with a bit of a current? Should the two Fluval outputs face each other from opposite back corners? Aaaaaaaaaaaaaghh! I am also wondering if the size of air bubbles would have any significance. <Really Mollies are going to be much more "concerned" with their water quality; pH, ammonia, nitrite, nitrate, salt content, and temperature.> One more, are their special needs for albino mollies that I need to know about? All of my other mollies seem totally happy. <Your albino forms maybe a weaker variety, but still I think if there is something wrong it is not circulation. Your Fluvals are rated for 340 and 180 gph respectively and the H.O.T. Magnum Pro no more than 250 gph. That is a total of 770 gph for a 72 gallon tank, just about right.> Oh well, I hope you can help me or send me in the right direction. Any information you can give me that I could really study and learn more about fish behavior would be great too. <There is much to peruse on www.WetWebMedia.com> Thanks so much, Amanda Best <Have a nice night! -Steven Pro>

Molly sensitivity and cycling I'm cycling an additional 15 Gal. aquarium (have established 55 gal.,3 10 gal., and a 5 gal already) and put in a couple platys, 2 adult Mollies (white Lyretails) and a couple half grown white mollies to aid in starting the cycling. <There is an alternative to subjecting the fish to harmful ammonia and nitrite spikes - do a google search on 'fishless cycling' - also, since you have pre-existing tanks, you've got a major help - just take some gunky filter media from an established tank and put it in with the filter on the new tank. A bit of gravel from an established tank would help, as well.> After 21 days now, the mollies appear suddenly stressed. The adult female was found dead last night, The adult male was in obvious trouble, and the two young mollies appear humped back, with swimming & breathing problems. <Very likely all a result of the cycle, I would think. Ammonia, nitrite, nitrate, and pH test results at the time would have given more insight, perhaps> I give them a dip in an antibiotic solution, then put them in a quarantine tank. The adult male seems to be recovering, the small ones are still questionable. The platys seem to be doing fine, although I treated the 15 gal. tank with the antibiotic (contains Nitrofurazone) before I checked the ammonia and nitrite levels. <A good med choice. Especially if it is ammonia/nitrite poisoning.> The treated water shows a trace of ammonia, and barely registers nitrite & nitrate (probably skewed by the medication). <Any ammonia whatsoever is bad. Any nitrite whatsoever is bad, as well. Both are quite toxic to fish, and will cause gill damage.> Are mollies more sensitive to nitrite, etc. than the platys? Any other suggestions? <Some fish are more sensitive than others, to be sure. Some of the molly strains are particularly inbred and weaker than other strains. Another point about mollies - they do much better in brackish or full saltwater conditions than in fresh. In freshwater, they prefer hard, alkaline water to remain in the best of health. In any case, water changes will be your best ally right now. Do plenty of water changes, get those ammonia/nitrite readings to zero -Sabrina> Thank you. Jess

Black Molly HI guys, <Hi! Ananda and Sabrina tag-teaming on this one... > I have a few questions regarding black molly care. Since the tank is going to be based around them, can you give me their basic water requirements, including salt levels in the aquarium? I have read anywhere from 1 tsp. per gallon to 1 tsp. per 5 gallons... there doesn't really seem to be any consistency about the information I have read. <A: That's partly because mollies can tolerate anything from freshwater to saltwater. You want plants, so you are probably going to want to use the really low end of brackish -- no more than 1.002. That's the specific gravity reading, and a much better way of measuring salt levels than "teaspoons per gallon". To measure specific gravity at low levels, you need a SeaTest hydrometer -- and yes, it needs to be that specific brand. Other plastic hydrometers are designed for marine use and don't measure the low levels. The glass thermometer-hydrometers are usually calibrated to 60 degrees, so you'd need a chart to convert that to the correct value based on your tank temperature. The SeaTest hydrometer is already calibrated to 76 degrees, so you shouldn't need a chart.> Also, if I were to add other fish to the tank in the future, what would make appropriate tankmates for them, from their natural habitat that is? <A: It depends, somewhat, on precisely which species of molly you get. Most commonly-available molly species show up in black morphs. And it's just about impossible to tell Poecilia velifera from P. latipinna, though you can usually tell them from P. sphenops. You may want to track down a book on freshwater fishes of the southeastern U.S. Finding some of the other fish native to that area is going to be difficult unless you can go on a collecting trip. Only a few are available -- and sporadically at that -- in pet stores. I believe the least killifish is one you might find. <<S: comment: the 'least killifish' is a tiny livebearer, not really a killifish - Heterandria formosa is their Latin name.>> The Florida Flagfish is another. Those are difficult to find, and you want to make sure you get at least one female for every male. Otherwise, the male will go after the females and get quite grouchy. He may even antagonize the males, nipping their fins, until he shows that he's the tank boss.> <<S: Others you might think about could be: variegated Platies (Xiphophorus variegatus), swordtails, (Xiphophorus sp.), Mosquitofish (Gambusia sp.), (even guppies ('feeder' type, if you're going for the whole 'natural' look). Of them, the swordtails will do best with the mollies, by far. All of these fish can tolerate light brackish conditions. Beware mixing Platies and swordtails, as they will interbreed. If you go high brackish, one fish to consider would be possibly the three-spined stickleback (Gasterosteus aculeatus aculeatus). They'll take a wide range of salinity, too.>> Lastly, could you also tell me plants that are from their natural habitat as well? <A: There are a few plants that will tolerate brackish water, and fewer of them that are available are from the same area that the molly is native to. The Florida mangrove is one such species, and can tolerate a much higher specific gravity than most other plants. Bacopa is found where mollies are found, but I'm not certain how much salinity it can tolerate. <<S: B. caroliniana, native to central America, may possibly tolerate low salinity, say, 1.002-ishSG, and is a pretty tough plant. B. rotundifolia is native to the southern US, but is not hardy at all, compared to B. caroliniana.>> The last time I did some research on this, I looked into estuarine biotopes and plants in Florida and Louisiana.> <<S: And mollies can be found all the way on down the coast and inland into central America, and even in southern California/northern Mexico and places along that coast and inland. Mollies are pretty widespread. Some specific plants to play with: Vallisneria spiralis and V. americana (north American natives) will both tolerate lo brackish conditions well; Egeria densa, a US (now worldwide) native, might even tolerate low brackish; hornwort (Ceratophyllum sp.) is distributed pretty much worldwide, so that's in; Echinodorus tenellus 'pygmy' or 'chain' sword (N. and S. America). Just some starter ideas. Any good plant book that tells plant species origins will definitely help you here, as well. A lot is going to depend on how strict you want your biotope to be -- if that's what you're aiming for. There are definitely some ideas for brackish plants if you choose to break away from the biotope idea.>> Thank you very much. <<Always a pleasure. Wow, we got long winded. -Ananda and Sabrina>>

- Acclimating Mollies to Saltwater - Hi. <Hello to you...> I sent an email before but didn't get an answer. <Many apologies.> I was wondering if you could help me with acclimating a mono to saltwater. <Ok.> My boyfriend has a 37 gal freshwater setup that includes 3 convicts, an ugly red parrot cichlid and a Monodactylus argenteus. They look very crowded, especially as it is a higher tank as opposed to wider. I would like to move the mono to my 55 gal reef tank. Right now I have about 40 lbs of live rock, some mushrooms, a coral beauty angel, a purple Firefish, a scooter blenny, a yellow clown goby and a white banded cleaner shrimp. The mono is rather large (at least compared to my fish). We bought him about 3 years ago. He was freshwater when we bought him and I wouldn't even consider the water he's in now brackish. Would it be possible to put him in my tank eventually? <Sure.> Would this be too stressful? <Not if you take things slowly, although mollies can move from fresh to salt quicker than they can go from salt to fresh.> I have a 10 gallon that I could use to acclimate him in. Is this too small? <It's a little on the small side but will likely work fine for the amount of time the acclimation will take.> If it can be done. how slowly do I have to increase salinity? <A couple of thousandths a day - say from 1.000 to 1.002, and perhaps even slower if you want to be extra careful.> Any help you can provide is greatly appreciated. Thank you. Nicole <Cheers, J -- >

- Acclimating Mollies to Saltwater, Doh! - J- Thanks so much for responding. <My pleasure.> I just wanted to make sure though -- I'm talking about a mono (Monodactylus argenteus) - not mollies. <Oh, I am so silly... my apologies.> Does what you wrote still apply? <Sure, in fact you can go a little faster if you want. These fish are actually saltwater fish.> Again, thanks for your time. Nicole <Cheers, J -- >

- Sailfin Mollie to Saltwater - Anthony et al while Bob is away, First off mates, this site, as I have told Bob before, is truly amazing and a help to both the animals in our care and those of us lucky enough to enjoy a small slice of the underwater world in our homes. My question is what would the crew recommend the process to take Sailfin mollies from lightly brackish (1.010 or thereabouts) to full NSW, I've got some 1 months olds from a breeding tank that I would like to move to a nano reef that has been set up for a year or so (refugia=pods =coral growth, thanks to WWM for that). I am going to place about three of the gold x silver Sailfin crosses in my small QT tank, how much salinity move per day and over what period might make this move successful. <A couple of thousandths a day - say from 1.000 to 1.002, and perhaps even slower if you want to be extra careful.> I figure that 2-3 weeks might be a good transition time and a good QT (figure it would lower chance of stress-induced ich from the change). <Well... freshwater ich and saltwater ich are two different protozoans so you wouldn't have to worry about introducing one to the other. The change to saltwater will kill the freshwater ich.> Once again thanks to all that WWM does, An appreciative friend, Joe <Cheers, J -- >

Makin' 'em Go Salty >hi, >>Hello. >I have read in books that you can change the molly from freshwater to salt water and I would like to try that but none of the books said how big the container you drip the water in should be so how big of a container would I need to drop the water at one drop per second and if you have any other ways to convert them pleas tell me. thank you, Joey >>Wowee! Can you really say all that in one breath? The size of the container is only important if you plan on keeping them there, Joey. If we're only talking a couple of mollies, then a large bowl (a gallon or two) is fine. They'll appreciate it if you go ahead and add a small air stone for aeration, too.. just don't make it too vigorous or they'll be bashed around (or, you'll get the toilet bowl effect on 'em). Do be sure to do this over a few hours, and WATCH their scales! This is really important, because that's your best sign that you're going too fast - if their scales begin to stick out like a pinecone, you know you're going too fast for them and need to add fresh water again and slow down the saltwater additions. Marina

Mollies, To Salt or Not To Salt I am in the process of setting up my new aquarium, a 25 gallon Eclipse and I was to have Mollies. After reading many, many articles on-line, I still have one major question- Brackish or Freshwater???? Most of the articles recommend adding salt, however I ran across this article by Kevin Yates, "The Great Molly Myth" which totally shattered my previous beliefs about mollies. So salt or no salt??? Thanks for reading. Marion Allen Brevard, NC >>Hello Marion. I believe mollies should be kept in water with a high pH, around 7.8, and medium to high alkalinity. Salt can be added, a tablespoon per 3 gallons of water, give or take. The exact amount doesn't matter, what DOES matter is pH, and water quality. Especially with black mollies, who should also be kept in warmer temps, around 80-82F. Make sure you test your water regularly for ammonia, nitrite, and nitrate readings. Keep the nitrate level low, say around 40ppm. Feed them a varied diet, including both vegetable and protein based foods. Keep a ratio of one male per three-four females. Give the females plenty of hiding spaces, like plants, for example, so they get a chance to rest and not be harassed by the male. They can be aggressive, so make sure not to overcrowd them. A 25g can safely handle around 10 mollies, with once-a-week partial water changes. Sailfin mollies will grow to around 4 inches, so understock those.-Gwen

Mollies Brackish? 4/13/-4 Hi :) <Hi, Pufferpunk here> I read your information about Mollies liking (needing?) brackish water -1T to each 5 gallons. We've a 75 gallon with 2 female adult mollies and their 35+ fry, two Corys, two shrimp (rock and bamboo), and four C.A.E. Our question is will the addition of salt bother the inhabitants that AREN'T mollies? <Mollies do best in salty water. They even thrive in marine. Your other fish won't like any salt at all. So, either keep your mollies in FW, expecting some illness & shorter lifespans, get a 2nd tank, or return the FW fish & have a BW tank.> Thank you for your time :) Mrs.. D. Pontrelli <You're welcome ~PP>

More Molly Questions Good morning, A few weeks ago I wrote in about our black Molly having fry. The fry are really big now and fun to watch. I've put 12 of them in the 29 gallon and 15 are in the 10 gallon and doing very well. The 10 gallon has excellent readings for the ammonia, nitrate and PH and we do a 10% water change every other day. <<What about nitrIte?>> The problem is the water reeks even after the water change. I rinse the filter twice a week and change it after 2 weeks. Why the smell? <<Are you overfeeding? And again, test the nitrites...and do NOT clean your filter media under tapwater that has chlorine. You are effectively killing your good bacteria every time you "clean" your filter. Bad idea. What kind of filter are you using? Rinse filter foam in old tank water, and make sure you have a BioWheel or some other form of biological filtration in the filter that you do NOT clean, in order to keep your good bacteria.>> Now the 29 gallon. Momma Molly wasn't doing so good. Checked the water and nitrate was sky high. Did an immediate 50% water change and added some "get rid of nitrate" and it's now down to 0.25 but won't go lower. <<Do more water changes. Are you testing for nitrate, or nitrite??>> Momma still not doing too good, eyes were bulging and staying at the bottom not eating... Treated entire 29 gallon with antibacterial.. antibacterial treatment of tank stopped 2 days ago and nitrate still at 0.25.. <<Keep testing for ammonia, nitrites, AND nitrates. Antibacterial meds will kill off your nitrifying (good) bacteria and you will have even more problems.>> Then Momma got some white spots so again 30% water change and added a quick "cure ick". First treatment yesterday. Should I do another "cure ick" treatment today? <<What do the directions say on the package?>> Changed to the food to your suggestions of Spirulina and BTW all fish love it. This morning Momma is swimming a little bit more and back to eating although she seems a little disorientated. I would like to transfer the 15 babies from the small tank to the large tank and put Momma and another orange female Molly that I suspect is pregnant in the small tank. Is this a good idea? <<No>> as I think Momma is stressed enough as it is and I don't like the smell of the small tank. <<You really need to do a lot more water changes in order to get your tanks into better condition. Make sure when you do your water changes that you are adding water that is the exact same temperature as what is in the tank, and use a good dechlorinator. -Gwen>> Thanks so much for your wonderful site and all the helpful information. Monique

More Molly Questions Good morning, Thanks for the quick reply and all the help. You guys and gals are a Godsend. Here's an update...Saturday morning I got up and one of the baby Mollies in the 29 Gallon was swimming around with a dead newborn in his mouth. Looked around and there were about 12 dead ones. Hubby cleaned that out and I called the pet store and they said they would take all my babies black Mollies...I kept 4 of them. I suspect Momma had other babies but these ones didn't make it. Now Momma is ick free, no more white spots) eyes are back to normal no bulging or white film), swimming around like there is no tomorrow and eating everything in sight again from the top of the tank when I feed MODERATELY and picking at the bottom (Colorbits 2 times a week as recommended)...She's back to following my finger around the tank and seems very happy. She's still in the 29 gallon. I'm running a Tetratec PF300 http://www.littlefishtank.com/Reference/reviews/display.asp?idkey=221 The nitrITRES, ammonia are excellent now. the PH is a little high 7.8 and I'm doing that test every other day. The rest of the tank - total of 3 adult mollies, 2 neon, 4 baby black mollies and 3 tetra neon are now very happy. No live plants in there just plastic. The 10 gallon...all the babies are gone to the pet store. did a 50% water change. ran the above 3 tests and all 3 results are perfect. In this one I'm running a TopFin for a 20 gallon. The only fish is there is an orange Molly that I suspect is pregnant and introduced (after reading your site info on how to properly introduce) after the babies were gone. I was guilty of overfeeding and have now learned a valuable lesson. If someone wants to keep their fish healthy and happy don't overfeed, don't introduce too many fish in the tank all at once and as this site and all the crew here recommends. buy the test kits and sample the water REGULARLY. I'll check into this BioWheel or some other form of biological filtration in the filter that you have mentioned. Learning quickly but correctly and VERY thankful for all your help. Monique <<Dear Monique; Good to hear the momma molly is doing okay :) Your pH of 7.8 is FINE, mollies require high pH, alkaline water, the opposite of what Neons like...keeping both species generally means one is not being kept in conditions they require for long-term good health. I am so happy to hear things are on the right track for you and your fishies. Keep up the good work! :) -Gwen>>

Black Mollies in Saltwater? 6/27/04 Hi, Hope all is going well there. <Hi James, Pufferpunk here & all is great!> I have a 75 gallon F/O saltwater tank. I have heard that black mollies could be acclimated to live in a saltwater aquarium. Have you know of success stories about this? <Yes, they can live & thrive in SW. When acclimating from FW, I would use a drip system. Put the fish in a bucket with the water from it's bag (ask for a larger bag) & slowly drip water through air tubing from your SW tank into it (you will have to tie a knot in the tubing). Only raising the SG .001-.002/hour. You may need to bale water out of the bucket, so it doesn't overflow.> Also, I have a pair of false perculas, a flame Hawkfish, a royal Gramma and a coral beauty angel. Would the mollies fit in with these guys? <Just make sure the mollies have smaller crevices to escape to, in case any of your fish go after them. I have found that a heavily decorated tank can make all the difference to "smaller" fish.> Thanks for your help, James <You're welcome, enjoy the mollies! ~PP>

Re: Black Mollies in saltwater <Hi, MikeD here> Thank you for your help. I have one more question please....I have read that it is best to keep mollies in groups of 1 male and at least 2 females. (I used to keep them when I had freshwater tank). If I just added a male, would it do OK without any more of it's kind in there?<Sure. The reason they don't suggest pairs is that males are considered "drivers", ALWAYS trying to breed with females, and if kept with just one she will often break down and become ill from the exhaustion of trying to get away from him constantly...the best mix is actually 1 male to at least 4 females> Thanks again, James<You're welcome> James Hall

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