Jerking fish - but not swimming oddly, FW Flush-a-rama  6/25/08
My tank is doing very well, with lots of aquarium plants and a variety of fish. However, about 2 weeks ago, I noticed a guppy was jerking. Just it's back half appeared to be moving back and forth oddly. This went on for 2 days. I finally pulled her out and flushed her afraid she was ill and didn't want to make others ill. Then, a platy started doing the jerk last week. I pulled it and flushed.
<...>
Now today, a molly is doing it. The tank is 70 gallons with only community fish in it, algae eaters,
<... Gyrinocheilus? Please read on WWM re>
cats and plats to keep the tank cleaned up between water changes. Although they are jerking, they do swim quickly away when trying to catch them to dispose of them. However, just as soon as I stopped trying to catch it, it settles somewhere in the tank and jerks again. Unless I'm chasing it or it's up eating, the fish just sit and jerk. I've flushed 2 and hate to flush the molly next. Any advise?
<... stop flushing. Read re water quality, Whirling Disease, Mycobacteriosis... on WWM, the Net, books... Bob Fenner>

Issue with Bala sharks, platy and zebra fish... little useful info.   5/5/08
Dear Crew,
<Grace>
You have always been a great help to me and again I come to you with problems I am at a loss with.
First and foremost, I have 4 Bala sharks (all fairly small) in my 100 gallon tank, the two smallest ones have been getting increasingly thin over the last few weeks. I was having an issue with my ammonia about 3 weeks ago but I resolved it within 3 days (it was reading between 0 and .25 and the thinness seemed to start prior to this) everything else has been good. But in the last 48 hrs the same two have lost all of their color around their face (one more than the other he even has a colorless line across the back of his "head" area and his fins seem to be eroding a bit at the edges). Lastly, it appears that behind their gills are red. Besides these two problems they are acting completely normal...I was trying to catch, at least the smaller sickly looking-er one but he's too slick. They are eating and swimming just fine. What on earth could this be? Should I be determined to QT them (might they "infect" my other fish) or will leaving them in
there be okay?
<Something amiss here. I would move these fish to another system pronto. Something smaller would be easier to observe, feed them in>
My next problem is regarding my QT tank. I have had a zebra Danio in there (he was laying on the bottom of the tank on his side and darting occasionally but now he seems fine except he is developing a "humpback")
<Mmm, could be developmental (genetically predisposed), but might be bacterial, perhaps protozoan in origin. If you have other Brachydanio, I would sacrifice this one (freeze it)>
and a Mickey Platy. They were both real sick for a while. But, they have been in there over a month now and one day they seem perfectly healthy and the next the platy starts her spinning, darting, hiding, and curving her tail and/or body (not her spine but she will curve herself while floating on her side). The platy was bought at Wal-mart (dumb i know) weeks ago and when I got her home I noticed she had a bright red large hemorrhage behind her one gill (and it even seemed opened) and she was swimming erratically and hiding. The gill is healed now though.
<... again, could be environmental (ammonia poisoning resultant), could be "whirling disease"...>
I originally thought she had a worm of some sort because before they started eating again (they have been eating for about a week now) a pile of clear/light brown worm-like looking things would show up on the bottom of the tank (there is no gravel or anything in there) hours after putting quick cure
<Oh! Formalin based... this could be "it"... very toxic... even to you>
or a jungle parasite clear in - and it seems like they will do better around that time but if I don't vacuum them out fast enough they will disappear (there has to be 100s of them but they do not seem to move or anything) and the symptoms will come back. I looked everywhere I could find at the library and on-line and none of the parasites match their description for looks and symptoms. I don't think platy has whirling disease because my understanding is it only affects trout or salmon family of fishes-plus there is not black tail (besides the "Mickey" logo)...Do you have any idea what these fish could have? Maybe how to help them. Thank you so very much
for your time, I am truly at a loss with these three.
Very Respectfully
Grace
<... Need more real data... water quality tests... photos... I'd move the minnow-sharks... Bob Fenner>

A little help with deaths and what to do please. FW troubleshooting/reading   4/1/08
Hey there!
I've had a 29 gallon setup for about 3 months now. I know I was probably quick to add fish to it, but I filled about 20 of the 29 gallons with cycled water from my dads 75 gallon, and the other 9 gallons from my brothers cycled 20 gallon.
<Good approach>
I set the filter up and let it run for a week, along with some Amazon swords and java fern. The first fish that I introduced was a male/female swordtail couple. They were very happy, so I went and got some more fish about a week later. I got 2 dwarf Gouramis,
<Colisa lalia... please read on WWM re>
2 gold Gouramis, and 2 2" albino Corydoras. No problems for a few months, every now and then adding another fish or two.
That brings me to where I am now.
I currently (as of 3 days ago) have 6 of these 1.5-2.5" albino Corydoras that I am moving over to a 40 breeder soon to try to breed. I have 3 female and 1 male swordtail, 2 gold Gouramis, 2 dwarf Gouramis, 1 .25" albino Pleco,
<Tiny!>
1 3 inch albino Pleco, 1 8" Pleco,
<Too large for this system>
and a 4" long silver Arowana
<!>
that is only in this tank until I get my 125 gallon to cycle. I have several small plants, nothing too big, and a large piece of driftwood that's
basically a sunken piece of firewood we found in a brook next to my house.
<Mmmm, how treated?>
I keep the temperature at about 79, to satisfy the silver Arowana along with the others. Not too hot, not too cold.
<Good point>
I have a Whisper 30 Power Filter on there, which my dad said was too small for the bio-load that I had in my tank,
<I agree>
so I put a second one in. I also use my Magnum 330 on it twice a week for 2 hours. I do 25% water changed weekly as well. There is also a small Aqua Fizz Airstone in the back corner.
Out of nowhere, I lost 2 females and a male swordtail in the same day. One of the females died directly after giving birth, and the other two followed within the next few hours. The last swordtail has what looks like stretch marks on it, and it has stopped eating and rarely swims now. I transferred that over to my 10 gallon with some cherry shrimps and 5 zebra Danios just to see if I could singly treat it. 2 days later, I lost 2 of my 6 albino Corys,
<Bad...>
Just checked my water for levels now, and my Nitrate is at about 50,
<Yikes!>
which is bad I know, but probably due to the adding of 2 bleeding heart tetra and 4 pearl Danios out of my brothers tank that has a bad leak. So I need to get that lowered somehow.
<See WWM re...>
My nitrite is at 0, Hardness is about 120. Alkalinity is at 120, PH is at 7.6. Ammonia Detector shows safe levels.
<Should be zip... I'd test otherwise>
Any idea why the sudden deaths?
<... Mmm, many possibilities... infectious, parasitic, environmental...>
The new fish didn't get added until after all of the dying had taken place. Right now all of the fish in the tank seem happy. Any idea what may have caused this and if I should be worried about losing more?
<I would. Yes. I'd move about half the bio-mass here... read on WWM where I've made comments above>
If you want some pictures of the tank and the fish within, I'll be glad to take some and send them over.
Thank you!
Justin Trask
<Reading. BobF>

Slowly dying fish, FW   2/14/08
Dear Wet Web Media Crew:
Thanks for your wonderful website, I have had an aquarium for a little over a year now, and have found all your information so useful! I have a 20 gallon freshwater aquarium, with rather hard water, since I live in San Diego (I think Bob Fenner lives a few blocks from me!)
<Ahh! In Mira Mesa, on the Penasquitos canyon...>
The tank started as a cold water tank with a goldfish, 4 white cloud minnows, and an adult and some juvenile platies (brought in from my half-barrel water garden). Last
September when the goldfish died, I raised the temp to 75ºF and added an angelfish and a Gourami; the latter died after 2 weeks. LFS said that they were difficult fish, and don’t often survive.
<?>
In November I added 2 more platies and 2 mollies. All was well until a few weeks ago when one of the white cloud minnows developed a kink in his back, became listless, thin, and died after a couple of days. A week later one of the November adult platies became thin, hung out at the top of the tank with fins waggling, or at the bottom. He ceased to eat and died. The following week, the same happened to one of the juvenile platies. I did a lot of reading on your site and concluded that they must be infected by a parasite.
<Possibly so>
I took the carbon filter from my hang-on-back filter unit and following the instructions, dosed the tank twice with Jungle brand Parasite Clear tablets, which contains Praziquantel, Diflubenzuron, Metronidazole, and acriflavine. I am left with one angelfish, 2 mollies, 3 white cloud minnows and 3 platies (2 female, one male). Two days ago, the 7 month old female platy, who used to be very fat and active, has slowed down, and wants to hide a lot. The male platy, who used to chase her constantly, leaves her alone now, and the angelfish tries to chase her when she comes to the top of the tank. She "slept" with the platies and mollies in a group last night, but is now hiding in the treasure chest or under the bridge. As of yesterday she was still coming out to eat. When she swims she is a little slower than usual. None of the fish had any exterior signs of infestation. Do I still have a parasite problem, or is the social mix of the tank changed so much that the little platy has become a victim?
<Mmm, could be either... perhaps just the medication exposure>
I have been keeping a close watch on the water quality, and all seems well, except that the nitrates are a little up, at 20ppm since the removal of the carbon filter (replaced after the meds were finished). I try and change 25-30% of the water weekly or bi-weekly.
<Good>
I do have a bit of an algae problem, but I scrub it off weekly, although the 2 live plants look a little black. I feed the fish a variety of foods, alternating between tropical fish flakes, steamed vegetables and peas, and freeze-dried bloodworms. The fish love it all, and I try not to overfeed them. Sorry for such a long post, but I want to be thorough. I did not quarantine my September and November fish purchases, and I suppose that was my mistake, but I don’t have a place to put new fish. Any ideas would be most appreciated, as I really like these fish, and am getting a bit discouraged by all the fishy funerals.
Thanks,
Allyson
<I would look about, be a bit more selective re your livestock sources... Aquatic Whse. and Octopus' Garden (both in/about Kearny Mesa) are good suppliers of generally healthy livestock. Otherwise, being patient with what you have done here treatment wise is a good idea for now. Bob Fenner>

Swollen bellies   2/5/08
Dear Sirs:
I have a problem with my tropical fish, bellies swelling and after a few days they die. What causes this and what can I do to fix my problem? It does not seem to matter what breed fish it is.
Thank You
Kevin
<Hello Kevin. It's impossible to answer this without some information. How big is the aquarium? What, at the very least, is the pH and nitrite concentration? How warm is the water? How often do you do water changes? How much food do you feed them? How did you mature the aquarium before adding the fish? You should probably invest in an aquarium book before buying any more fish. It is almost certain your fish are dying because of poor water quality -- i.e., you are putting too many fish into a tank that hasn't been matured. The filter can't cope with the ammonia they produce, and the fish get poisoned. Read this article for a quick primer:
http://www.wetwebmedia.com/FWSubWebIndex/fwset-up.htm
And then have a read of this summary of how and why we need to mature the filter in an aquarium:
http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm
Once you're sure you understand the theory, then you will be better set to embark on the hobby. Buy at least two test kits, one for pH and the other for nitrite (with in "I", as oppose to nitrate with an "a"). You'll use these to monitor water quality. Cheers, Neale.>

Mysterious Deaths 2/8/07
Hello WWM Crew,
<Hi>
I am writing on behalf of my boyfriend - mostly because it's my "fault"  that he is now a fish keeper. <A nice hobby to share.> We've recently been experiencing some bizarre deaths in his tank. A bit of background info first :  he has a 55 gallon freshwater ( purchased around the beginning of September of 06 - was cycled for about a month before adding fish... I gave him the sponge and some water from my tank just to help kick start things ). <Good> The water levels are all normal  - ammonia 0, nitrite 0 and nitrates at 10ppm. The current temperature of the water is 76 degrees ( it was a constant 74 but I suggested he turn it up a little... ). He has a Penguin Bio-wheel 350 filter and three different air stones for aeration. No live plants or any other aquatic life that we know of besides the fish. <Ok>
The only fish that are in the tank are platys - all of them the result of the "fry explosion" in my tank. :) <Like rabbits I tell you.>  I didn't count how many small ones we transferred but I will guess-timate around 30-35. Up until recently everything was going very well. A couple did die in the first couple of months - noticed as some of them grew their spines weren't straight so I would assume that was the cause.  <Most likely genetic.>  Lately though there have been at least three or four dead each week over the past  three weeks - we're down to about 20 platys now. <Hmmm...>  The only thing that has really changed is the amount of time that he keeps the aquarium light on - he had been leaving it on for 10 hours or more a day but he's cut that back to approximately 6. <Should not be an issue.>
I did some research on the site but I didn't come across anything that was similar to our situation. Is it possible that these were fish that were simply "defective" and nature is taking care of itself? <Yes, although after a few months the weak would most likely be gone.> Is there something else we should be testing for beyond the norm? <Not really.> I really don't know what to do and to be honest I feel rather bad that all these little critters keep dying. Any help or ideas are greatly appreciated. Thanks!
Geri
<Are they all able to eat.  Sometimes the smaller ones can be bullied out of food and starve.  Also need to watch for signs of disease obviously.  Beyond that I would most likely chalk it up to genetic problems that are manifesting themselves now.>
<Chris>

Another disease question, FW, troubleshooting  – 10/18/07
I have a 55 with 2 blood parrots, 2 clown loaches, a Cory cat and brown severum. 4 weeks ago, I lost a parrot (did have 3) to a white protrusion just behind his left eye. I treated him with tetracycline over a two week period but it obviously didn't do any good.
<Hmm... white protrusions don't kill fish any more than people don't die from warts; it was more likely the only visible symptom of an underlying problem, perhaps with water quality or diet.>
The tank is heavily filtered and aerated and I change water every 4-6 week, cleaning the gravel and the lake.
<Not sure what the "lake" is in this instance. Anyway, 4-6 weeks between water changes are NOT acceptable. You have a heavily stocked aquarium: Clown loaches, Severums, and Blood Parrots are all big, messy fish and you need to be doing 50% water changes each week. At minimum!>
Last night I notice my severum had a swollen lower lip. Today, it has grown larger. He loves looking at us, so I had no problem shining a flashlight into his mouth but didn't see anything. I will probably take him out of the tank and do a more thorough inspection. I'll bet he'll love us for that!
<No. Unless you're a vet, removing a fish for closer examination will likely produce no tangible benefits while actually stressing the fish further. In addition, netting and handling fish damages their scales and mucous layer, making them more susceptible to secondary infections.>
If I find no obstructions, any thoughts on what I might be dealing with?
I wonder if his mouth problem might be related to the lose of the parrot cichlid?
<A swollen lower lip is most likely caused by an opportunistic secondary infection. Possibly from rough handling (e.g., with a net); sharp gravel; fighting with another fish; or attempting to eat something venomous or spiny, like another fish. If the skin on the lip is intact but just swollen, then probably the best thing to do is optimise water quality and keep an eye on things. If the lip shows signs of being bloody or broken, or there is excess white mucous or dead skin, then using an antibacterial (Finrot remedy) would be adequate. These generally work well against the Aeromonas and Pseudomonas bacteria that tend to cause infections on broken skin. Randomly treating with antibiotics (such as tetracycline) doesn't do any good unless you know specifically what bacterium you're dealing with, since antibiotics are all limited to certain bacteria. Finrot remedy is generally a useful first-call when you're dealing with minor to mild secondary infections on the outside of the fish. As ever, do a nitrite test and a pH test as well, so you can check the water quality and water chemistry are where they should be. All cichlids are VERY intolerant of nitrogenous waste; in other words, nitrite and ammonia must be ZERO, and nitrate as low as is practical, and certainly not more than 50 mg/l. Do also check diet; Severums are herbivores, and one of the best ways to make a Severum sick is to feed it nothing but flake and meaty foods. Would you keep sheep by letting them eat steak? Of course not; and yet cichlid keepers routinely ignore the fact that most cichlids are omnivores and many, including Severums, feed primarily on algae and soft plants. Just like humans, without the vitamins they need, they are more prone to disease.>
Thanks
Frank
<Cheers, Neale>

New Topic - Unexplained fish distress!?  – 08/22/07
Hi to all the WWM Crew. It is Victor here again.
<<Hello, Victor. It’s Tom again, as well.>>
I last wrote not too long ago regarding high Ammonia levels and poor water conditions. With the help of Tom this issue was finally resolved... or so I thought!
<<Ammonia again, Vic???>>
Firstly, I have a heavily planted 50 gallon Freshwater Aquarium. Livestock are 2 Golden Algae Eaters (they are mature and I have had no
compatibility issues yet despite their reputations),
<<Does happen from time to time, Vic. Count yourself very lucky and enjoy…>>
18 Rasboras, mainly Harlequins but 2 are Ghosts and 3 are Hengli, 8 mixed Platies with 5 Fry who are doing well,
<<Glad to hear this.>>
2 Angels, 1 male and 1 female (I know this cause they recently bred).
<<Pretty much a dead giveaway and, likely, the only way in the world you’d ever know! :) By the way, you’ve got a full house.>>
Water conditions are:
Ammonia 0
<<Whew!!! Very glad to see this!>>
Nitrite 0
Nitrates 0.50
PH 7.4
Temperature 27 C
<<All looks good on paper, Vic. Congratulations!>>
I add 1 teaspoon of Aqualibrium Salt per 10 gallons,
<<I confess ignorance regarding the effectiveness of this product, Vic, not that you were necessarily looking for a “yea” or “nay” from me on its use.>>
Water conditioner and Plant supplement as directed on the instructions.
Recently 1 Rasbora was seen to be gaping mouth wide open staying at the top of the tank and seemed very distressed, so I put it down using Clove Oil. No other fish seemed affected.
<<Sorry about the Rasbora. Never an easy call…>>
I assumed it may have been long term gill damage revealing itself after my Ammonia Crisis.
<<A possibility.>>
A few days later I noticed all fish seemed to be breathing through their mouths heavily and not their gills and as my water conditions (or at least the ones I test for seemed ok) I commenced with water changes of 50% which seemed to alleviate the problem for 24 hours. However the scenario would then repeat itself.
<<From a certain aspect, this is good. We know that the “conditions” test good. Now we need to concentrate on the “quality”. Two different animals.>>
So I started more aggressive changes of 85%, last one this morning.
<<Excellent, and when we get to your next question, I’ll tell you why.>>
There seems to be no obvious reason for this mystery. Could decaying plants harm fish?
<<You bet they can! Plants absorb and hold, or retain, bacteria. Or, at least as long as they’re alive they do. Dead plants release this bacteria back into the water. VERY important that you prune/remove dead plant matter from the tank ASAP. In a heavily planted tank, such as yours, this is even more important.>>
Maybe too much plant supplement? My tap and rain water have all been tested and are untoxic. However I have only just started adding rain water during water changes, could pollutants I cannot test for be the cause? After all, I live in a big city... What am I doing wrong?
<<Wrong? Nothing, and I applaud your conscientious efforts to preserve fresh water supplies. There is a “hitch” to using rain water, though, which is that pollutants can be problematic depending on your locale, prevailing winds, manufacturing in your area, etc., etc. Though you had the wisdom to have your rain water/tap water tested, I’d be inclined to look into this first since your fish only recently started stressing. Stick with tap water changes, only, for a while and see if the stress on the fish is alleviated over a longer term. Would be a shame if the rain water were the “culprit” here because I like your thinking.>>
Any guidance would be appreciated. I am stressing myself out over this.
<<Don’t stress out over this, Vic. You have a couple of avenues to pursue. It’s when the ideas run out that it’s time to “stress”. There IS an answer to your problem. We just have to find what it is.>>
Have I got it wrong and fish breathing through mouths instead of gills is normal as long as no other signs of distress are present?
<<First, the gills don’t work independently of the fishes’ mouth, per se. Water taken in through the mouth passes over the gill plates which extract oxygen into the fishes’ systems. In an “oxygen rich” system, you probably won’t see a lot of “gaping” mouths on the fish. The occasional “swallow” does it for them. Deprived of an oxygen-rich environment, the fish will attempt to pass larger quantities of water over their gills, which might account for the gaping mouths. They will even resort to gasping at the surface air in order to obtain oxygen…something you don’t mention about the remainder of the fish. So, the direct answer to you question is that your fish don’t breathe through their mouths (in this context) as “opposed” to breathing through their gills. They breathe in conjunction with both their mouths (for water intake) and gills (for oxygen uptake). Now, all that said, oxygen in a heavily planted tank should not be an issue. If the plants, by and large, are thriving, I would assume an oxygen-rich environment for your fish. Concentrate on “aqua-gardening” to remove the dead plant matter. Go slowly with any supplements. In fact, stick with the water conditioner during (tap) water changes and eliminate the use of the other supplements for the time being. Might be “too much of a good thing”.>>
I hope I have given enough information and thank you in advance for any advice given.
Victor
<<Plenty of good information, Vic. Wish we weren’t back at the “trials and tribulations”, though. Please, keep me posted. Cheers. Tom>>

Many problems, please help! FW maint., Dis. troubleshooting, env.     8/22/07
Hi there. I have had my tank established for about half a year now and up until now, it has been doing rather well. I managed to eradicate a serious white spot problem without any losses, and was feeling very happy with the health of my fish and the water quality.
I have a 120L Juwel Rekord aquarium and about 30 fish, most of which are no bigger than 5cm and some that are smaller.
I recently had a serious outbreak of hair algae, and so changed all of the water, got new plants and completely cleaned the gravel and decorations. The tank looked wonderful and clean, until I decided to change a few filter sponges, and it soon became completely covered in dirt. I waited for the dirt to settle and then did a thorough gravel clean and hoped that the filter would suck it up again (which it did), Anyway... This seems to have all culminated in a serious problem that I cannot solve. The water is now full of floating particles that look like specks of cotton wool. They get sucked into the filter and then seem to come straight back out again. two of my neon tetras have weird, raised white patches on their mouth and gills (I have 6 altogether) . Many of my fish are also acting erratically, flicking themselves on the gravel and occasionally darting about in zig zag motions. I treated with an anti fungal medication but I haven't noticed any improvements. I know that this is usually a sign of white spot, but I have not noticed a single speck (for now, anyway...).
I keep my airstone activated at all times to provide extra oxygen as I may have overdosed on the med. When it is turn off, my mountain minnows will often hang about at the surface, gasping. I have been trying my hardest to keep the tank clean and do regular (about once a week) water changes of 50%, and I am now at my wits end.
I just get the feeling that my fish are suffering. Many of them have red gills and their behaviour is not what it was. I regularly test my water and nitrites and nitrates are both almost 0, the PH is at about 7 and the water is hard. I just don't know what to do. Could the illnesses be related to the weird stuff floating about? and how on earth can I get rid of it when I don't have a clue what it is? I am feeling so frustrated.
Any help will be appreciated so much as I love my fish and just want the best for them.
Thank you in advance for the wonderful service you provide.
Anna
<First, clean out your filters. Take the sponges from the filter box in the corner of the tank and give them a thorough clean in a bucket or two of *aquarium water*. Do not run them under the tap! What you want to do is wash away all the solid waste while leaving the bacteria happy in the sponge. Replace the rather pointless carbon and nitrate sponges with a couple of new regular sponges, maybe one mechanical filter sponge and one biological filter sponge. Your filter will now perform its job much more efficiently. Now, remove about 50% of the water, and replace with new water (dechlorinated, of course). While you're siphoning out the water, stir up the gravel a bit so you can suck out any detritus. From the way your fish are behaving there can be only one of three things going on: [a] The temperature is too high; [b] The biological filter isn't working; or [c] Something toxic has got into the aquarium, such as insecticide or paint fumes. The white threads in the water are most probably colonies of blue-green algae. These form slimy mats or bushes on flat surfaces, but when disturbed the threads float about, often in vast numbers. Dealing with blue-green algae is difficult, because nothing much eats it. So you need to get back to basics, making sure the conditions in the aquarium don't favour the blue-green algae. High nitrate/phosphate levels, sunlight, overstocking, and decaying organic matter all seem to promote blue-green algae. I sometimes find it easier simply to take a tank apart, keep the fish and filter running in a bucket, and then thoroughly clean the tank from top to bottom. Otherwise, installing fast-growing plants like Hygrophila is a good way to deal with algae, assuming you have enough light for them (the default Rekord hood doesn't have enough lighting). Finally, I suspect you will need to treat for whitespot, though in this case stress is probably the immediate cause of the problem and will need to be fixed as well. Hope this helps, Neale>

Re: Many problems, please help!   8/22/07
Hi Neale, thank you very much for your help. It's funny you should mention paint fumes, as we have been doing some painting around the house recently so that could indeed be a part of the problem.
<Ah, the plot thinnens. Keep the door closed to the "fish room" and open a window, so the air can freshen up. Do big water changes to dilute the toxins.>
I was just wondering if you feel it would be okay to put fresh gravel in the tank, as whenever it is disturbed, lots and lots of algae begins to float about the tank and then
settle right back down again.
<Not only is it safe, it's advisable, if you think the gravel is irredeemably dirty. The exception here is if you use an undergravel filter. Assuming you do not, then change the gravel if you want. This will have no effect on biological filtration.>
Would it be okay or should the current gravel just be cleaned thoroughly, I'm not sure if getting rid of it would upset the biological balance of the tank.
<Unless you have an undergravel filter, you can change the gravel once a week if you want.>
Also, would it be okay to change 100% of the water or would this be very upsetting for the fish?
<Treat as if you were introducing the fish to a new aquarium: put fish in bucket of old water. Replace 100% water in new tank. Make sure pH and hardness are roughly the same as before (slight differences don't matter, but going from pH 6 to pH 8 would be bad!). Now empty half the water from the fish bucket. Every 5 minutes, add a litre or two of "new" water from the aquarium into the bucket, so that over the next 30 minutes the bucket is filled up with half old water and half new water. Empty out 50% of the bucket, and repeat the process. By the end of the hour (which should be, say, 6 or 7 additions of water) your fish be completely acclimated to the new water conditions. Catch them with a net, and put into the aquarium. Don't put any old water from the bucket into the aquarium. I've done this many, many times even with delicate things like halfbeaks and never had problems. It's a variation on what marine fishkeepers call "the drip method". Freshwater fish are, almost by definition, able to tolerate quite drastic water chemistry changes (e.g., droughts, heavy rainfall) but still, you don't want to take advantage of it.>
Thank you,
Anna
<Cheers, Neale>

What's going on? FW env. issues, dis. troubleshooting   8/6/07
Hello,
<Ave,>
Your site is great. I have spent countless hours reading the articles and FAQs and have gained much knowledge and have benefited greatly from the advice. I have a couple of strange problems however that I am sure are related, but have no clue how to resolve them both.
<OK.>
Problem 1) Is that my water has been cloudy for two months straight.
<This happens.>
I have patiently waited and waited, but there is no sign of it easing up. It is obviously a bacterial cloud, as you can see it rolling by in tufts like smoke.
<Non sequitur. You certainly can't "see" bacterial clouds as obviously different to clouds of silt. The latter are actually quite common in aquaria. If you introduce too much gravel or sand that hasn't been washed of silt properly, and then don't have enough mechanical filter media to remove the said silt, you end up with cloudy water. Some fishes that root about the substrate, such as goldfish, barbs, cichlids, etc. will simply exacerbate the problem.>
My water quality is perfect; NH3=0ppm, NO2=0ppm, NO3=<10ppm, Ph=7.2, Alkalinity =1-3dKH, GH=<1dKH, and the temp is 78f. What is strange about these readings is the low nitrates.
<The KH reading is a bit low, and GH reading way too low. Unless you're keeping seriously soft water fishes like Apistogramma, this is not really acceptable water chemistry. For standard tropicals, you want about 6-18 degrees GH (German hardness) = 100 to 300 mg/l calcium carbonate, and around 5-10 degrees KH. Anything much below these values lacks the water chemistry stability and won't favour the development of biological filter bacteria.
I have kept fish for the past 30 years, and have always had massive algae growth and every since I began testing for NO3, have always had high readings over 80ppm despite all the water changes, cleanings, etc. Now all of sudden I succeed in bringing the NO3 down and poof? the water turns cloudy and it seems like the NO3 is keeping itself down!
<Admittedly seems odd, but I think part of it is the very soft water, which algae (and bacteria) don't usually like.>
These water conditions have been stable since the cloud appeared which makes me wonder if the cloud is not a mitigating factor. I have of course had clouds before, caused by over cleaning, over feeding, polluting rocks, wood, etc., but have always remedied the situation within a week or two. Never before have I had perpetually cloudy water. There are 3 events that preceded the cloud that must be suspect, and they are 1) I found a new home for my football sized Pacu. 2) I got a new filter (Eheim Pro II) to
replace the little Cascade and Tetra Tec filters. And 3) I added 2 new pieces of Malaysian drift wood to the tank.
<OK. Nothing there seems an obvious factor, except perhaps if you have insufficient mechanical filter media in the new filter.>
I got rid of the Pacu for obvious reasons (size mainly), and replaced some of his mass with 3 silver dollars, 3 Corys, and a Pleco. The filter change was because the Tetra Tec made far too much noise and the combination of the 2 filters were moving too much water and the currents had the new smaller fish swimming for their lives just to stay stationary.
<Well, I'd disagree with your resolution here. Silver dollars and Corydoras live in moving water with far more current than most tanks, and plecs couldn't care less since they suck onto thing. You almost can't have too much current in a tank. Certainly, around 6x the volume of the tank in turnover per hour would be perfectly in order for these fishes. I run one of my tanks at 10x turnover, and once they get used to the exercise, the fish are fine.>
Also, they had to aim into the current which had them swimming toward the back of the tank which only leaves their other side for viewing. Before leaving the Eheim alone, I ran the Tetra Tec in parallel for 2 weeks while the new filter cycled. Everything was still fine at that point. The added wood came from a reputable aquatic dealer and I conditioned it for several days before adding it to the tank, by alternately boiling and scrubbing until the water stayed clear and the scrubbings resulted in no loose or soft debris.
<Could be fungal decay I suppose, but unlikely.>
The water was still fine after this until 2 weeks later when I did a standard cleaning when I vacuum ½ the gravel with a 20% water change. The tank clouded up a bit which it usually does, but didn't clear. Instead it progressively got worse and is still in full bloom.
<Don't fixate on the cloudiness. Take a belt-and-braces approach. First, assume its silt, and add "filter aid" to help a freshly installed wad of filter floss suck it up. I've done this, and it works very well, usually in 24 hours. Second, now assume it is bacterial, and focus on the water chemistry. The water chemistry could stand with a bit more hardness, and all else being equal things should improve. I'd personally remove the fish to buckets, remove the filters, do a 100% water change, fill up with new water, acclimate the fish and filters back to the new water chemistry *without putting any old water into the new tank* and then see what happens.>
Problem 2) Is that I cannot grow algae anymore. I have successfully reduced the nitrates to less than 10ppm and probably phosphates as well (I do not have a phosphate test kit), and now the algae has gone from a runaway problem to extinction.
<I suspect because of the water chemistry.>
What algae there was on the wood and plastic plant leaves has died and turned a dark color. You might wonder why this is a problem, and it is because I have 2 new bushy-nose pleco's that have nothing to eat.
<Put out some thinly sliced cucumber, courgette, blanched lettuce, etc each night weighted down with lead weight and let them graze happily.>
I had one prior, that died, I assume from starvation, but do not know for certain. I got 2 more that are very small, and I am worried that they will meet with the same fate. I try to feed them algae wafers, but the glutinous silver dollars eat every bit of everything that hits the water.
<Silver dollars are omnivores and need plant material in their diet. So use algae in the day time for the silver dollars, but add some algae wafers at night for the Ancistrus.>
I even tried over feeding by continuously putting algae wafer after algae wafer into the tank thinking that the silver dollars would get full and leave some behind for the other fish, but after 26 wafers were dropped in and devoured I had to give up because I was afraid of the resulting pollution, and believe me there was pollution.
<I bet. Ancistrus are nocturnal; silver dollars are not. Feed one with the lights out, the other during the day. Easy peasey.>
After that feeding episode there was a pooping frenzy like I have never experienced. You know haw amazing it is to change a babies diaper and find a pound of poop when you feed them only a few ounces of milk?
<No, I have no idea about this and don't want to imagine it. Sounds horrid.>
Well then you can picture the substantial piles throughout the tank. It looked like a completely new bed of substrate. Anyway, I would like to know how to either grow some algae or otherwise feed my pleco's.
<Feed 'em at night.>
I actually want to know what is going on. I am thinking that the cloud would go away if I removed the wood, but I am not sure and therefore I don't want to throw the tank into another direction of unbalance until I know why my NO3 is staying so low.
<Try it; remove the wood, see what happens.>
Do I have anaerobic bacteria eating it?
<No.>
If so, how can I use this to my benefit and still produce some algae for the pleco's?
<Don't concentrate on algae for the Ancistrus. You'll never produce enough of it for them to live on. Use vegetables and algae wafers, and let them graze on algae as and when they want to.>
Here are the specs on the tank:
* Size = 75 gallon
* Type = FW
* Occupants = one 5? silver dollar, three 3? silver dollars, three 1? albino cats, two 1+? albino bushy nosed pleco's, and one 1+? blue ram.
* Lighting = 32w 4? AllGlass tube (I think it is 6000K), on for 12 hours per day (on a timer). Tank catches 2 tiny rays of sunlight through cracks in the blinds at sunset for approx 15 minutes.
* Substrate = epoxy coated in good condition (black colored - it turns white when it wears out)
* Décor = 3 medium/large pieces of Malaysian drift wood, one has been around a while and 2 are new. Several plastic and silk plants.
* Filter = Eheim Pro II canister (275GPH) w/ built in heater. On a power backup so it will continue running during a power outage.
* Filter attachments = water surface skimmer (10% of the flow), 2 other pickups very close to the gravel (90% of the flow), exhausted to a long spray bar for soft flow on water surface, and one jet at mid-tank.
* Filter Media = 1L tube shaped porous ceramic-like things (called Bio Max), 1? sponge, 3L cylindrical porous ceramic-like balls (looks like bleached coco puffs)(called substrate pro), 2 bags Chemi-Pure, and a fine mechanical pad.
* Water = Reverse Osmosis reclaimed using RO Right to 110TDS, Baking Soda to 3dKH, and Freshwater Essentials.
* Water conditions = Ammonia = 0, Nitrites = 0, Nitrates = <10, Ph = 7.2, Alkalinity = between 1 and 3 dKH, General Hardness = less than 1dGH, Temp = 78f
* Maintenance = 20% water change weekly, clean filter each new moon, vacuum ½ of the gravel 1 week after each new moon
* Food = Hikari Cichlid Staple, Hikari Micro Pellets, Tetra Algae Wafers, Hikari Daphnia
* Frequency of feeding = Usually once a day, sometimes twice, sometimes I skip 1 to 2 days without feeding. Mostly use the cichlid staple and micro pellets, and occasionally (1-2 times per week feed the wafers), daphnia mostly goes down the skimmer, so I don't try to feed with it very often.
Sorry this is so long, and thank you for taking the time to read it.
Scott
<Hope this helps, Neale>

Strange disappearances of adult fish in a swordtail + molly tank – 07/24/07
Hello WWM,
<Didi>
I've had some strange disappearances in my tank, and am wondering if swordtails and mollies can eat each other in their fully grown state.
They have no teeth, and can eat babies only because they are small, but a full grown fish......??
<Mmm, no... might pick at carcasses though>
Here's some background. I've had this small dorm-room-friendly 3-gallon tank since February, with 3 fish in it: a male molly, a female swordtail, and a male guppy.
<Too small a world...>
They lived happily there and after a month the female gave birth. At first, I wanted to keep just one of the babies, so I separated it in another container. Disappearance #1 happened a couple of weeks later when one day the baby disappeared from its container. There were two inches between the water level and the edge of the container, and the baby was so young it was still transparent (less than 1/4 inch long), so it couldn't have jumped out.
<Agreed>
I have no other animals, and nobody enters my room without my knowledge.
The container hadn't been knocked over or anything. I just woke up one morning and the baby was gone, the shelf around the container dry and everything... The container had no decorations and nowhere for the baby to hide. It was just gone.
<Perhaps stolen?>
So I decided to look through the tank with the mother for another survivor, and found the last two babies still alive, hiding in the rocks. I took both out and they grew up in that same haunted container, until they were about half the size of the other fish - too big to be eaten. Then I put them back in the tank with the others. They lived there in peace until the larger of the two was almost as big as its mother. Then, one night, disappearance #2 happened. I fed them before going to bed, and everybody was there. I woke up the next morning, and the bigger kid was gone! The tank has a closed lid, so it couldn't have jumped. I took apart the filtration system - nothing; I took out the decoration - nothing. No body, no body parts, nothing. It was almost as big as the adults!
<Mmmm>
A couple of months passed and I built a larger tank, 16 gallons. After the initial period of empty cycling, I bought a test fish, another female swordtail adult, to put in it to test the environment (and potential toxicity of glue residues). I couldn't dump her right in that day, so I put her in the smaller tank for the night. The other fish (initial trio plus the now fully grown second baby) didn't chase her much, and by the time I went to bed they were all at peace with each other, eating together. The morning after, she was gone! Again, I took the tank apart and there was no sign of the body whatsoever.
Disappearance #3.
<Mmm, does someone have a cat in the dorm?>
Maybe my fish want to keep a certain number of roommates, and kill the extras? The day after, I got yet another test fish, another female adult swordtail of the same color and size. She has been in there for almost a week now, but nothing has happened to her yet. The other fish seem to be okay as usual. I got a bunch of zebras to test the big tank with, and they are in there establishing the environment. Right now I'm more interested in observing the dynamics of the small tank.
<I understand>
I know 3 gallons is not enough, that's why I made the big tank. The fish have gotten used to the space in the small one though, and haven't fought or chased each other at any point of time, so aggression wouldn't explain the disappearances. They have never reacted violently towards a newly introduced fish either, so they don't seem to be aggressive. All the fish that disappeared behaved normally until their (presumed) death.
None were sick. What I would like to know is if cannibalism can explain the mystery... because there's nothing else I can think of other than alien abduction! I don't believe it's cannibalism, since these fish have no teeth and couldn't tear the body of another adult apart. Even if they could, wouldn't at least the bony head remain as evidence?
<Yes>
Also, when I was younger I had a 10 gallon tank with lots of swordtails, mollies and guppies for 7+ years, and none ever disappeared like that. I haven't heard of adult cannibalism either. Please help me resolve this! I have no idea what's going on. I don't want any more fish disappearing!
Thanks,
Didi
<Predation from outside and thievery are my two main guesses. Bob Fenner>

Re: Strange disappearances of adult fish in a swordtail + molly tank – 07/24/07
Hello again,
<Hi there>
Just wanted to respond to your two guesses (predation from outside and thievery) with a bit more information. Predation: animals other than fish are not allowed in our dorms, so no cat or any other animal has ever been in the same building (!) with my fish. Plus, even if a cat were to live in the same very room, the tank has a heavy plastic lid with built-in lights that snaps shut, so no cat could open it unless it had opposable thumbs and the arm leverage of a human. Thievery: our door locks, and my roommates and friends all love and care for the fish, so nobody could have stolen them either. In fact, the entire floor of my dorm has been shocked by the disappearances and has been trying to help me resolve the mystery (by suggesting explanations like alien abduction... I know, but still, they are on my side here). So neither predation nor theft explain the disappearances. At the time the last fish disappeared, I had already moved out of college, but in my current apartment the chances of thievery and predation are even smaller because it's a private house with locks on every door and three adult residents including myself, with no pets and no evil intentions.
Any other guesses...? You can't believe how confused I am :-S
Thanks,
Didi
<Well... let's bring in the second string/B guesses... Fishes can die, decompose in a surprisingly quick way... and.. there is a jumping, and flipping a few feet away, drying up "floor jerky" possibility as well... BobF>

Re: Strange disappearances of adult fish in a swordtail + molly tank   7/25/07
Hello yet again,
<And to you>
Yeah, that did cross my mind. But again there are a couple of problems with these hypotheses. During my previous 7+ year experience with these species of fish, I had some die, and I observed the decomposition process. It can be quick, but never overnight, and all of the disappearances have taken place overnight (as in, from evening to morning). Also, whereas the fish that died before did so out of sickness or weakness, the ones who disappeared were perfectly healthy and active up until the moment of disappearance. Another thing that happened once before (also back in the day) was a fish jump out and flop its way across the room, but that's because my tank wasn't covered. The current 3 gallon tank, from which fish have been disappearing, has the snap-on heavy plastic lid with built-in lights. There is no way a fish can get out of that thing. There is also no way for a fish to get lodged into the filtration system, because it's a simple pipe with 2mm-wide slits on the sucking end and an above-water outgoing end with water cascading down from it. The filter itself is raised above the water and enclosed in a plastic container.
<Okay>
I know I'm not making things easier by refuting your guesses, but I'm just trying to rule out the impossible. The impossible seems to be:
jumping, theft, predation, cannibalism/murder by other fish, decomposition, filter accidents, spilling, and any kind of breaking out on the side of the fish :-) Maybe I should accept it as an irresolvable mystery.
<... up to you>
If you experience a sudden revelation and think of something that hasn't been listed and discussed already, please let me know. Otherwise, I wouldn't want to keep bothering you with my riddle.
Baffled,
Didi
<Maybe... with the last of J.K. Rowling's Potter works out now... they've disapparated? Cheers, BobF>

Help my fish is dying - I can't help without more useful information!  – 6/12/07
I have a Plecostomus floats on its side.
<Not a good sign. How long has this been going on?>
The tail fin is either nipped off or deteriorating off.
<None of the fish you mention would below would likely cause this sort of injury (although I'm not sure what a "small ground feeder" is...); I'd be willing to bet this is tail rot, a condition typically caused by poor water quality. Have you used a quality liquid test kit (Aquarium Pharmaceuticals and Tetra both make good products) to measure the levels of ammonia, nitrite and nitrate in the water? The former should be at zero, while the latter can safely be as high as 20 ppm (though lower is better). How large is this tank and how often do you do water changes? What type of filtration is running on the tank? I need lots of information to be able to help you/your fish...>
I have added three neon fish and a dojo fish to my tank that all ready had come with the Plecostomus another small ground feeder that has never changed sizes for the last three years and another fish not sure what it is. I haven't had any problems with them until I added this dojo and neons. What should I do?
<Test your water for starters. Most fish illnesses and diseases are caused by poor water quality; remedying this underlying environmental cause often times will solve the problems. However, I can't say for certain without additional information; see questions posed above. In the meantime, start reading: here's a good place to begin - http://www.wetwebmedia.com/FWSubWebIndex/fwsetupindex.htm
Best regards, Jorie>
Thanks Cassi
 

Re: Dropsy?#2, FW system prob.s... Still...   5/30/07
Hi Bob, I would like to thank you for your reply – it was quite some time ago but I wanted to thank you!!! … and as your "No"s predicted - my hospital tank was bad (not sure why, I need to do more research on it). I have lost all the fish I put in there (Maracyn-two, original water, 5 gallon tank, 8 head and tail lights and three Cory cats), except one Cory, but she is still with us (She got the name of popsicle in memory of my victims. Her fins are healed, but she has no whiskers (???).
<Happens>
The missing info from my first e-mail:---We are using straight CO2 from a cylinder through a regulator that is controlled with a probe check.---The ph was 7.2 because that is what Chris set up at the start. I asked him why, he said he didn't remember. I checked again Fishbase and that ph should be ok for the discus, the cardinal tetras should not like it… but they are relatively ok… I changed the ph to 7.1…
---I clean the bottom and do water change (1/3) 2x/ week, use either RO water or tap water for the water change mostly tap water… did you recommend RO water to make sure we are not putting in trace elements, chemicals with the tap water, right?
<To at least dilute these>
(I am having issues with Chris on this – he says “Vancouver water is great and the fish were ok before, something else is wrong…”
(((… well… he regularly lost fish before… I didn’t… until I decided to kill them with my “hospital” – torture tank :-(… sorry for the blabbing…)))
Since my first e-mail:
---I cleaned the filter as I noticed that the flow was a lot weaker. (tank temperature water only)
---I keep a strict cleaning schedule
---cut down on food
But I am still in a mist... I don’t know what could be the problem…
---whiskerless Cory cats??? – could be that the bottom is not good for them?
<Very often the case or a contributing factor, yes>
---my two discus girls are still having issues; I try not to over worry, but… both are a bit bloated and sometimes have freckle looking brown spots on them.
<Have you ever "wormed" them? Should be done... See WWM re...>
If I do a thorough cleaning and at least 1/3 water change those seems to disappear. If I do ¼ waterchanges only, the appear again. Also:
---One is darkening
<Bad sign>
and is aggressive with the other one time to time.
---The other one is getting lighter and the tail rot is worse a bit,
---Now 2 of the cardinals have a white spot on their back. Just above their tail fins.
---About the SAE/flying fox (Crossocheilus siamensis or oblongus or Epalzeorhynchos kalopterus – we got them as the last one): we got two of them 1.5 ago. One was growing, had the stripe unless got stressed (((died about 6 month ago after some weird time when I had to do emergency water change, because all of them were gasping for air –
<? What is going on here re your water quality, DO? Something is amiss>
this was before we got the discus girls and the new decoration and plants…))) but this one just always looks stressed, yellowish color, does not grow, has weird movements, and is restless, now getting skinnier and lighter color and I can see something black inside him – even a “black thing sticking out from the anus” (no, not poo, this thing is always there…) could that be a parasite? (I did not research it, but remember reading something like that…) Now getting more quiet…
---I still have blue algae although I think it is not growing as fast as before…
---I still have a thin layer covering the top of the water that I have to remove after every day.
---Plants are still not growing well enough.
<... I...>
I know that dropsy, pop-eye and the fin rot are symptoms only, … (and will never panic again and try to use meds… until I know 100% sure that it is bacteria and know how to set up a tank for it.) but I am frustrated. I really like my little fishes, I can’t even dare to keep Cory cats anymore even though they used to be my favorites, the discuses are so great as well as the cardinals and I want to have a great home for them.
Please let me know your thoughts…any other good guesses are greatly appreciated. :-)Thank you!!!
Eva & Chris (Bo, Dory, Popsicle and the gang)
<I would have someone from the fish shops you trust, and/or someone from the local fish club/s come out and look over your system, your MO for maintenance... there is decidedly "wrenching in the works" here. Bob Fenner>

Sick fish, FW   – 05/21/07
<<Hello, Robert. Tom here.>>
My daughter’s fish is sick but I can’t find out what is wrong. He has black smudges on his stomach and is swimming vertically with his head at the bottom. Been like this for two days. What do I do?
<<Robert, unfortunately, you’ve given me very little to go on here. Fortunately for you, that’s never stopped me before. The “black smudges” sound like wounds that are in the process of healing. (With fish, their skin/flesh turns black when they develop scabs on wounds. Actually, this is a good sign. Most likely, the fish has been scraping its stomach on the bottom of the tank.) It also sounds like your fish has swim-bladder disease. Basically, this means that, in simple terms, it’s constipated. If your fish will eat, probably the easiest thing to do would be to feed it peas with the shells removed. Peas act like a laxative and will help the fish eliminate the food from its intestines. Do not feed the fish its normal food. If it is eating, this will only make things worse. Better not to feed at all. As a “last ditch” effort, I would recommend two teaspoons of Epsom Salts in a large bowl of tank water. Place the fish in the bowl for no more than ten minutes. This, too, has a “loosening” effect and can aid in clearing the blockage. Without more information, this is the best advice I can give you. Best of luck. Tom>>

FW fish illness troubleshooting     5/16/07
Hi, there.
<<Hello, Simon. Tom here.>>
I have a 500 ltr tank complete with Fluval 303 and 302 external
canister filter that I bought from a friend. Since stocking the tank I have had nothing but problems with illness and I just can’t seem to get it under control.
<<You don’t offer any history on the tank/filters here. The filters are of an older generation so I assume that the equipment was used by your friend. Was all of the equipment cleaned properly/thoroughly before you set it up for operation? I think it a little unlikely that anyone would tear down a completely pristine aquarium of this size so I’m going to assume, once again, that the overall “health” of the system may not have been 100%. One thing to consider, anyway.>>  
I have purchased an API pro test kit and test weekly.
<<Good for you on this one.>>
My water doesn’t usually change much.
<<In a properly cycled aquarium, it shouldn’t change at all, Simon. A very slight fluctuation in nitrates and/or pH might be expected but a system as large as yours should remain very stable if it’s properly cycled/maintained.>>
I do have a pH of 8 and I can’t get it down.
<<Probably not the greatest of concerns right now. There’s a wide range of fish that will fit into an environment with this pH level provided you took this into consideration when you stocked the tank. Better to leave well enough alone for the time being.>>
I cleaned my aquarium three weeks ago and found little white worms about 5-8mm long in the bucket. I thought that this could be the cause of all my problems but when I treated the tank with an anti- crustacean parasitic it killed about thirty percent of my fish although my water is a bit unbalanced after this as it killed the bacteria in my filter.
<<I’m going to call this one an “honest mistake”. A common one, in fact. The worms you found, possibly Planaria, were indicators of a problem but not “the” problem. Invariably, the little creatures show up when there are excess nutrients in the water, typically uneaten food. Inadequate filtration, excessive feeding and lack of cleaning, particularly DEEP into the substrate, are most often the cause(s) of this condition. As an aside, when you test your parameters, keep a close eye on nitrate levels. Regardless of what you’ve been led to believe about the “safe” levels of these, you want to strive to keep nitrate levels below 20 mg/l (ppm) and, the closer to zero that you can get them, the better.>>
This is after just starting to get back to normal. My situation still hasn’t changed and my fish are still ill although they seem to want to breed.
<<First, I’m going to strongly suggest that you don’t treat a tank for anything unless you’re absolutely sure of what you’re treating for. There’s no room for guesswork. Deep vacuuming and regular water changes are going to be your “best friends” for now. Depending on what your test readings are, I would recommend water changes in the range of 20%-30% per week until your readings come back to zero for ammonia and nitrites and below 20 on nitrates. Keep in mind that if you’ve got readable levels of either ammonia or nitrites, you’ve got a problem that must be addressed with much larger water changes, 50% or greater. One more thing I’d like you to consider based on my personal opinion is upgrading your filters. I don’t feel that the filters you currently are using, especially based on their ages, are adequate for a 500 litre (~132 gals. U.S.) tank. In real-world terms, I doubt that you’re getting much more than one complete water exchange through these filters, combined, per hour. That, in fact, may be optimistic. Additionally, there are “schools of thought” that canister filters aren’t the optimal style of filter for biological filtration. You might want to consider one larger-capacity canister filter and one, perhaps two, HOB bio-wheel styled filters. Just thinking out loud here, Simon, but I think it’s worth looking into.>>
Can you please help me?
Simon
<<There’s little doubt in my mind that your problems are all environmentally related here. Not a big stretch on my part, quite honestly, since nearly all problems in our aquariums can be narrowed down to poor water conditions of one sort or another. In the short run, keep up on cleaning/water changes. Down the road, look into newer, higher-capacity filtration. I’m willing to bet that your situation will take a big turn for the better. Best of luck to you, Simon. Tom>>

Sudden Death in my 15 gallon tank   4/12/07
Dear WWM crew,
<Greetings!>
I've been reading a lot of information from your website and learned a lot too. However, I have a mysterious death in my 15 gallon tank, which I hope you could give me some opinions and suggestions.
<Mysterious deaths -- first of all water tests for nitrite, nitrate, and pH.>
This 15 gallon tank has 7 neon tetras and 2 Cory catfish. They were very happy in this tank until 2 days ago. When I fed Neons yesterday, they did not come to eat. I did not think too hard at the time. Before turning off the light, I gave some food for Corys. This morning I found the two Corys did not eat either. I tried to feed Neons and see if they now got appetite. They did not want to eat at all.. So I knew something went wrong.
<Hmmm... while Neons can be delicate (thanks to neon tetra disease) Corydoras are generally pretty robust.>
The water quality has been very stable and the tank is cycled. I tested the water regularly and couldn't see anything that could possibly go wrong.
<OK, what are the values here? What's the pH? What's the nitrate?>
All the 9 fish started to swim around in upper area of the tank at noon. Corys swam crazily together on the glass.
<When fish do this, it usually means the water conditions are very bad, and they're trying to swim to better waters somewhere. Rather like humans in a smoke-filled room. At the very least, do a 50% water change at once, and then repeat every day until you figure out what the problem is. New water never does any harm, and diluting pollution and/or toxins will always help.>
Then every one of the Neons started to be alone in the tank. By the time 4:00 pm I lost 3 Neons. later I lost the other 4. All Neons died suddenly and Corys seem to be still struggling.
<Not good. Neons can't breathe air like the Corys can, so tend to lose out when water conditions decline.>
I couldn't see what could cause the sudden death so fast. To make sure my water quality is no problem, I had some water from the tank tested by LFS in the evening. They said the quality was good, not toxic at all. They think it could be the lack of Oxygen. Will this cause such a sudden death in the whole tank?
<Yes.>
One neon might have neon tetra disease, but I am not 100% sure. The red color is not very red. If it is neon tetra disease, will it affect Corys too?
<Neon tetra disease generally has a very clear set of symptoms. First loss of appetite and the infected fish swims by itself. Then  it loses colour. Then it dies. Neon tetra disease has been reported from a variety of fish, as diverse as goldfish and cichlids. That said, it doesn't commonly infect anything other than Neons, cardinals, and perhaps a few closely related tetras.>
The two Corys are still listless in the tank.
<Please do water changes. Those'll help.>
I really hope I know what the real cause is, so I could fix it and save them. Could you please give me some suggestions? Thank you for your time.
<Impossible to know without doing the water tests. Assume the worst. Replace the water in the aquarium, clean the gravel to remove any decaying organic matter. Re-boot the bacteria with some appropriate product (such as BioSpira Freshwater) or some mature filter medium from another tank. Don't add any more fishes until everything seems normal. Check the water chemistry every couple of days, and don't overfeed the fishes. Almost all "mysterious" fish deaths come from water quality/chemistry problems.>
CC
<Cheers, Neale>

Death of Bottom-Feeders - 04/04/2007
Recently I added 4 sm. Cichlids (Malawi) and 2 lg. Synodontis multipunctatus to a 55 gallon tank that had been semi-vacant for about 3 months.  The story on the tank:  In December I experienced a power outage that lasted 4 days (cold, cold weather) which killed everything in the tank except the Pleco. (after a 7 year run and 1 tank born & raised cichlid)  Since the Pleco. was still going strong, I left the tank running (e.g. heater, filter still running). Three weeks ago I decided to put some fish back in the tank.  So I serviced the bio-wheel filter and did a 15% water change; checked pH, ammonia, and nitrate levels.  Everything looked fine.
<So far, so good.>
So I added the livestock mentioned above.  All was well for the first 2.5 weeks.  The fish all appeared happy, healthy, and active (eating well too).  Then, I came home to a dead Synodontis.  The other Synodontis looked to be struggling (i.e. acting sluggish, non active, etc.).  The next day I came home, the other Synodontis was dead as well.  I also noticed at this time that the Pleco. (whom had been in this tank for 7 years and survived the power outage) was acting out of character.  Pleco. pronounced dead about 6 hours later.
<Very odd. If it is only bottom feeders that died, there are two obvious possibilities. One is something toxic only they were eating. Not likely, but possible. Perhaps a batch of catfish food past the sell-by date, or some bad seafood put in for them it. The more likely possibility is lack of oxygen through poor water circulation, perhaps coupled with anoxic decay somewhere in the substrate. Hydrogen sulphide can develop in pockets where anoxic decay occurs, and the gas produced is lethal to fish. But because it oxidizes very quickly to something harmless, it is most dangerous at the bottom of the tank where it hasn't had a chance to oxidize. Having said this, while I've seen lots of anoxia in garden ponds and to some extent aquaria, I've yet to see it cause fish deaths. I'm sure it happens, it just isn't all that common. A third possibility is that it isn't swimming position that matters, but taxonomy. Catfish are (supposedly) more sensitive to copper than many other fish groups. Is it possible that too much copper got into the water somehow? Medications are one source, but usually the dosages are too low to cause harm. But my thing here is that if this was the case, it would have to be something you did around the time the Synodontis were introduced, given the plec was fine before that. The fact the cichlids are fine is decidedly odd; the one time I've seen a sudden dying-off of fish because chemicals were accidentally spilled into an aquarium, the cichlids were the first to go, and the catfish mostly survived. So to be honest, I'm stumped.>
Meanwhile all 4 cichlids appear completely normal.  Again all relevant parameters were measured and all is normal.  I did a water change and got down in the gravel with the siphon but am very confused as to the death of the bottom-feeding livestock in tank.
<That's certainly what I would have done, thoroughly cleaned the entire tank. In fact, my temptation would be to chuck away all the old substrate and install something new, in case the coral sand or whatever you has is polluted somehow. I can't think how exactly, but since coral sand is cheap, it's a bit of no-brainer really.>
I hope you can help and thanks in advance for your time.
<Sorry couldn't be of more help. But so long as the tank is cleaned and the water is changes 100%, you should be safe to have another go.>
Lon Hoover
<Cheers, Neale>

2 sick fish, a crash on the horizon? FW trbleshtg.  – 03/09/07
Dear Wet Web:
<Michelle>
Thank you for your site, I have spend many hours on it and have avoided many pitfalls... except perhaps the following.... I couldn't resist and purchased a baby whale, perhaps going over my fish inch per gallon quota.  I've had him/her for a week and have been feeding him farm-raised black worms from aquatic foods.
<Irresistible to Mormyrids>
As of yesterday one of my otos won't leave the plant or eat, he basically collapsed on the java fern, and a male honey gourami who'll eat twice his body weight if you let him, is no longer eating.  What have I done?
<Let's see>
Tank: 38 gallon tank, 0 ammonia, 0 nitrite, <20 nitrate,
<To "set" this as the upper limit... every bit contributes to mal-influence>
ph 7; 2 Eheim filters ea. capable of servicing 35 gallons, 10% daily water change, bi-weekly carbon change; well planted.
Fish: 3 peppered Corys, 3 Sterbai Corys, 2 panda Corys, 3 otos, 1 betta, 2 golden wonder killies, 2 dwarf gouramis, 2 honey gouramis, 1 betta, 6 silvertip tetras, AND a baby whale.
<Mmm, all should be compatible here>
The Corys and otos I've had for 3 years, with the exception of the recent baby whale addition, the others have been with me for 6 months to 1 year.
What are your suggestions as to the sick little Oto (they're such lovely little guys, all three usually hang out on lily leaf) and the honey gourami, and on my overstocking?
<The stocking should be fine, as stated. The one Otocinclus may just be "old"... this small catfish species only lives a few years... the Colisa... perhaps filling with roe... From what you've presented, I would not do something "overt" like apply a "medicine" or tonic of some sort... The old standby of increasing frequent partial water changes is advised>
  The baby whale seems to be doing fine.  
Hopefully, the Corys don't eat all the black worms (they slurp them up like spaghetti).
<Oh yes>
Very gratefully yours, Michelle
<Again... these appearances, goings on, may be coincidental... I would not panic if the rest of your livestock appear as you relate. Bob Fenner>

Re: 2 sick fish, a crash on the horizon?   3/11/07
Dear Wet Web & Mr. Fenner
<Mich>
Hello again.  Thank you for writing, I was quiet excited to have a response... it takes days to hear back from my vet sometimes (I have 5 dogs and 1 rabbit.... all rescue, including the rabbit).
<Neat... we have three such dogs...>
  Nothing much has changed.  The Oto and the honey gourami aren't eating and the gourami is hiding.  Regarding the Oto, he looks like he has a hunched-back and his breathing is rapid.
<Mmm, patience here>
The 'sick' honey gourami is a male.... do males carry eggs?
<Mmm, no>
I was just about to dose with Maracyn II, but will wait. The baby whale is still doing well, he made a 'home' under driftwood but comes out as soon as the lights are turned off.
<Typical>
  How often do you recommend feeding the black worms.
<If not too small or thin, every two days>
As of now I'm feeding them every other day, on the alternate day I feed frozen brine shrimp (not sure if the baby whale fancies frozen food) and wafers.
<Meaty foods for sure>
The non-bottom feeders get a mix of pellets and all the above.  I don't feed 2 days out of the week.  What happens to the black worms that don't get slurped-up?
<Live in the substrate... till they do.>
Regards, Michelle
<BobF>

Re: 1 sick little Oto  - 3/12/07
Dear Mr. Fenner & Crew,
Regarding the sick Oto and honey gourami.  The gourami died but the Oto is still hanging on... He's lost his round belly and is breathing rapidly.  I moved him into a hospital tank and set the temp to 82.  What medications do you suggest given that he's not eating.  On hand I have Maracyn, Maracyn 2, Maracyn Plus, Maroxy, Methylene Blue, BiFrurane+.  I'll use/buy whatever you suggest.
Regards, Michelle.
<Mich... this is too much guessing to suit me... If it were me, mine, I would not "treat" this little catfish period... Just hope. Bob Fenner>

FW white spots, but no ich  - 03/02/07
I have two,  3" severums, 5, 3" convicts, 1, 3" Nicaraguan cichlid in a 75 gallon tank. Water changes are 40% weekly.
<Good>
I've had the severums since November '06. They had been treated for ich before I bought them and were quarantined for 1 month after I brought them home. No signs of disease so I moved them to the 75 gallon fully cycled tank. In mid January I noticed a couple of white spots on one severums tail fin only. They were whitish and about the size of the head of a pin.
<Mmmm, could be "something else">
I netted the fish for a closer look; firm, tiny whitish lump under the skin along the rays. I've tried to find out what it could be and have experimented a little:  increased temp to 86F and added non-iodized salt to 1 TBSP/gal for two weeks. The original spots have gone, but now there are more smaller ones and the convicts are showing similar signs.
<Interesting>
Only the fins are affected. Some of the convicts have what looks like a whitish thickening along the fin rays and some just have one or two tiny spots.
The severum originally affected has approximately 7-10 tiny spots on the tail fin. The Nic remains unaffected. They all eat normally and I've offered a varied diet. I've been very diligent about keeping the water very clean, but I think the problem is worsening. I would appreciate any information you could give me as well as options for treating it. I haven't attempted a picture because the spots are so small as to be invisible on a photo. Thank you very much in advance, Anna
<Well... w/o sampling and microscopic examination all this is speculative... could be that these "spots" are encysted or not worms of a few sorts (likely monogenetic trematodes)... could be protozoan... maybe a Microsporidean... Not likely the Holociliate, FW Ich... though... am almost sure that this organism is present in almost every system... "waiting" for opportune circumstances. The reality of treatment here? I would likely do nothing but keep up with good maintenance... There are anthelminthics, some pretty general organophosphates (e.g. Fluke Tabs)... but the likelihood of benefit from using such is not enough to attract me. Bob Fenner>

Parasite or bacteria attacked my fish ;-( please, help... FW trblshtg.   2/24/07
Good day. This is Anna.
<Hello Anna>
At first please accept my accolades for maintaining such great free-source web site. I dag into all freshwater sections and noticed that many aquarist, at a certain point, experienced problems similar to mine.
The suggestions you had given to others helped me bring my tank to the equilibrium (after a month of a desperate looking for help and answers). I got Bio-Spira and get rid of ammonia in my tank. My pH is stable and my tank seems to be in cycle.
<Good>
Now, my problem is parasite, or bacteria.
<Oh?>
My 10-gallon tank is filled with 3 callistus tetras, 2 neon tetras, 1 female red sword-tail and 1 butterflyfish. They get along pretty well and I am really grateful that they accepted me and the environment I provided ;-).
However, ca. 5 days ago I noticed that my red sword fish had a white spot on the right-side of its body and tiny white dots on the caudal fin. I gradually increased the temperature till 85 degrees and started treating my tank with Maracide and Maracyn Two.
<Good>
The white spots on the sword fish's caudal fin disappeared; yet a white 1-2mm string of I-do-not-know-what started sticking up on its nape region. The fish is eating well and generally behaves okay, but I noticed that sometimes it "seats" at the bottom of aquarium (does it scratch itself?).
<Yes... fishes do>
I am worried that my initial diagnosis was wrong. I am afraid that red sword got bacteria or fungus, not necessarily ich.
<Me neither... however, your reaction/treatment was/is appropriate>
I assume switching medicine from one to another might harm my fish. What should I do?
<Mmm, perhaps wait and see for a few days to a week... Often such observed phenomena as you relate are directly, indirectly traceable to "treatments"... Not infectious or parasitic disease>
Should I get a hospital tank and put all fish there and do the massive water change or should I rather keep fish in the main display and continue treating it with another medicine (Maroxy or Maracyn). I noticed you suggested some baths... Will that work for me? How long can my fish by under medication?
<I would leave all as is... if you had a small microscope... I might encourage you to make a body slime scraping... take a look... But I would hold off on any other medicine exposure for now... If there proves to be more of the manifestations on other fishes bodies... a strict treatment with an organophosphate ("Fluke-Tabs"), might be my "next guess" (I'd use the 'scope)... in treatment... For trematodes.>
Please help me and my fish...
Anna, NYC
<Bob Fenner>

Re: Parasite or bacteria attacked my fish ;-( please, help..., FW    2/25/07
Bob:
<Anna>
Thanks much for a rapid response. It gave me a relief... and I have to acknowledge that my little success was because of your website :--) Literally I learned a lot and save all my fish! :--)
<A pleasure to serve>
Well, if I saw your answer earlier I would have hold off with moving my fish to a quarantine tank...
Anyway, I moved all fish to the hospital tank (bare bottom) and decided to let the display flow without livestock for 4 weeks.
<Okay>
Hospitalized (or maybe vacationing :--) fish seem to be happy - eat regular amount of food and swim all over the place. I will keep my eyes on them and will refrain from further using of Maracyn 2 & Maracide (the 6 day treatment was completed) with exception to Copper Safe (I noticed the full treatment should take a month).
<Mmm, two weeks is about all the exposure that will do any good here... and there is a corresponding "ramp up" of likelihood of harm, toxicity, with further exposure>
Now, I am thinking of my butterfly fish that has a different eating habit than my tetras and red sword. I guess with daily siphoning of the bottom I might have to feed him with stick...otherwise he might go hungry...
<Yes... good to check on at least ammonia accumulation as well>
Thanks again for your web site and discussion group and that you found time to answer my question....
<Welcome>
I will strongly recommend that great source of information to other helpless aquarists... One point to highlight - not everyone is fluent in English - would you consider having your web site available for non-English speakers?
<Absolutely. If this is indicated, or obvious (from suffixes of email addresses for instance), we/I give wide allowance... and the site is mirrored by others, in various stages of completion, in seven other languages... to refer people to>
Thanks much.
Anna
P.S. I will visit your site for any future reference.
<Be chatting, Bob Fenner>

Re: Parasite relief (hopefully) + Bio Wheel filter question   2/26/07
Bob:
   <Anna>
  Thank you :--)
   <Welcome my friend>
  Ahh that marketing... I will follow your advice regarding CopperSafe (of course the commercial instruction says 1 month... what's worse - the manufacturer even encourages switching to another medicine - "try other products" - he says - "if the present one does not bring results.").
   <Ho buoy!>
  I keep watching the hospital tank - fish is doing better. They swim around, breath normally, eat well, etc. The red sword lost white spots. I also see the quality of its excrement visibly improved (not stringy white, rather short and brown). I keep the temperature high (83). Also, I added 3rd "aeration stick" (to increase the level of oxygen) and placed a vitamin pyramid.
   <All good moves, observations>
  There is something I would like to share with you (please, do not laugh) - I feel like I have better relationship with my fish after all that we have been experiencing together. I did not realized that fish can be such an amazing pet (intelligent and very responsive).
   <Mmm, this is all certainly the case...>
  Today, I did 30% water change in the display tank and put back carbon to my filter (to help remove medication). I washed all artificial plants and vacuumed gravel. In the future I would like to add an Emperor 280 Bio-Wheel filter which, after 1 month of concurrent activity, would replace the "old" filter.
   <Good>
  And here is my question... Should I use that powerful Bio-Wheel filter in my 10-gallon tank? The instruction says the filter will move ca. 280 gph of water... that sounds to me like a whirl creator...
   <Try it and see... not likely "too much"... there are many places in the world where the water movement is much more vigorous>
  Please, share your insights...
  P.S. - I help my father with his 50 gallon tank.... Thanks to your web site I could better explain to him the importance of partial water changes and quarantine (he lost all 10 neons he bought last week :--((
   <Ahh, a pleasure>
  Thanks much for letting me be a part of your great network.   
  Anna
<Thank you for your kind, encouraging words. Bob Fenner>

Question: all new fish die (but not old ones)   2/24/07
Hi
<<Hello, Vito. Tom here.>>
Thank you for a most informative site, I've spent many, many hours on it and learned a lot.
<<Glad to hear it.>>
I'm having problems with my 3-month-old aquarium that I haven't been able to
solve either with information from any site or my LFS help. In short, new fish die very rapidly when introduced into my aquarium, within 1-3 days. Existing fish do just fine and show no symptoms of stress.
<<Interesting. Unfortunate for the new fish, though.>>
Set up: 50 gal freshwater, rather heavily planted tank (for a new tank, at least). Lifeguard outside filters (including a fluidized bed); 130 W lighting, 10 hours a day; carbon dioxide fertilization (compressed gas), with pH controller. Water parameters: Temperature 80 F, pH 7.1 (confirmed with a wet test kit), KH 4-5, GH 10 degrees. No measurable ammonia, nitrite or even nitrate (never saw a cycling spike). Maintenance: 30% water change once a week, with some vacuuming (just the most unsightly detritus), never skipped so far. I hope I didn't forget any useful information for you here.
<<All sounds good to me, Vito. A commendable effort on your part.>>
Animals: 3 adult swordtails, about 15 fry of assorted ages (in a breeder); 1 Siamese algae eater. A fair number of snails.
<<Well, you’re certainly not overstocked for a 50-gallon tank.>>
Plants growing well, though I'm thinking of adding some potassium nitrate, as older leaves tend to become yellow and die off. Algae (green and hair kinds) within reason. It looks very bright, but with plenty of hiding places, including a nice, dark cave.
<<Again, this sounds fine.>>
I've had 2 algae eaters die within 48 hours, though a third one did fine and is still in. Then I introduced a couple of Kribs, and they also died in short order. Same fate for 3 more algae eaters. I'm adding no more than 3 fish at a time, at least a week apart.
<<I’m going to assume that the “algae eaters” are of the same type that you have, i.e. Siamese Algae Eaters. The Otocinclus species of “algae eater” is very difficult to acclimate and notorious for having a high mortality rate early on. I mention this both for information’s sake and because Siamese Algae Eaters aren’t widely available, locally, in my neck of the woods. If these are, in fact, SAE’s, count me as a little envious that your local LFS has such a ready supply of these neat little fish.>>
When I bring new fish in, I transfer them from the bag into a plastic container. Then, over about 20-30 minutes I double their water by adding cupfuls from the aquarium, to get them adjusted gradually, and finally net them.
<<Close to exactly the same procedure I follow with my new additions, Vito.>>
The fish appear awfully stressed throughout the process (and who can blame them?), and even while hiding in the tank they stand on the bottom in one spot breathing very fast. Their behavior seems to normalize after a several hours, and they come out normally. Yet later on they go into hiding again and soon after they die (2 of them were never even found in spite of a thorough search).
<<You’re confident that the plastic container you initially use to acclimate the fish is free of any contaminants?>>
I had a few tanks years ago, but the new fish never seemed so stressed as now. There's no major difference between the water in my tank and the LFS. No harassing going on in the tank. The LFS person suggested I keep the lights out for 1-2 days when new fish are introduced, to reduce stress. It didn't really help.
<<A good suggestion from them even if it didn’t help.>>
All fish (except the swordtails) come from the same store, which seems quite professional to me. I watch fish carefully for a while when buying, and they always seem to be doing OK. Also, I live in Florida, so temperature shocks during transport etc. are not a concern.
<<Thanks for providing this information. Would have been one of my suspicions.>>
I read fish can adjust to high nitrate levels, if given enough time. Do they perhaps need a while to adjust to very low nitrate levels, as well?
<<No, but a reasonable question nonetheless.>>
I thought perhaps of some water contamination from the air in the house (cooking smoke, pesticides?), but should it not harm the fish already in as well? Especially small fry, I think, should be very vulnerable to poisoning, but they're growing fine.
<<I agree that the fry should serve much like “canaries in a coal mine” here. They’d be the first to show problems with toxins in the water.>>
I don't know what to look into any more, but I'm to the point where I feel bad buying any new fish, I'm dooming them. But I can't find a solution, as I don't have problems without new fish. Any idea of what I may be overlooking?
<<I suspect there’s something unseen going on in the display tank that affects only the new, stressed fish. Measurable water parameters/conditions seem virtually ideal and not far different from the conditions that the fish were in at the LFS. After going over your post, I think your problem lays with your plants, specifically the dead or dying plants. Dead plants and/or foliage release the bacteria they’ve absorbed back into the water particularly when they’re not removed quickly. Your older, unstressed fish, even the fry, aren’t adversely affected by these higher concentrations of bacteria but the new additions may well be, fatally it seems. Make sure you prune and/or remove any dead foliage/plants quickly. Before you add any new fish, perform a large water change to assist in cutting down on bacteria levels. Only add the new fish when you’re confident that all the plants are doing well and after doing the water change I’ve suggested. If what I suspect is correct, you will have a much better shot at success with your new fish.>>
Your help would be very appreciated. Thanks.
Vito
<<I won’t mislead you with a “guarantee” here, Vito, but among the more plausible explanations I can offer to you, this one seems to be the one you can easily address with a “hands-on” approach. I would highly recommend setting up a quarantine tank in the future, as well. Everything else you’re doing sounds pretty much “textbook” to me. Best of luck. Tom>>

Re: Question: all new fish die (but not old ones)  – 2/26/07
Thank you for such a prompt reply, Tom.
<<Happy to do so, Vito.>>
I will confirm the algae eater is in fact a true Siamese algae eater (never found it elsewhere I lived) and that it does its job wonderfully, i.e. the effects of its feeding are quite noticeable. They show up in the LFS only once in a while and I'm told they all sell very fast.
<<I can imagine!>>
Thank you for your suggestions. I will try pruning the occasional older dying leaf even sooner when it begins to get yellow. Your hint about the intermediate transfer container may also be useful, so I'll keep a watch on that. My concern with a quarantine tank is that it's an extra change for fish that are already stressed, through water conditions that are necessarily different from the main tank. But I know there is a lot of wisdom in the practice, especially considering the risks of getting the whole display tank sick.
<<I love it when someone has done his/her homework.>>
Whatever the cause of my current problem, it's really reassuring to know it's not something I'm doing so obviously wrong, and the fish are getting my best effort given my current knowledge.
<<Nothing in your procedures is wrong. That’s, in fact, why we have to look “beyond”. Fish don’t die for “no reason” and, given your practices, there should be no reason for this to be occurring on this scale.>>
I will continue investigating the situation (perhaps an extra tank for quarantine will help test different hypotheses), and if/when the cause of the problem is found I will let you know, if it's something that might help others as well.
<<While moving fish is, as you’ve suggested, stressful, they’ll have had time to “calm down” and be relatively stress-free. This might come down to a “good news, bad news” type of situation. The QT might allow your new fish to live and thrive when moved (good news) but we might not know what causes “stressed” fish to perish (bad news) in the display tank. Let’s preserve life first and concern ourselves with the “why’s” later.>>
Best
Vito
<<And mine to you, Vito. Tom>>

Need add'l info. to answer this...first suggestion is to check water quality.   2/20/07
I have had my Bala sharks for some time now. I noticed yesterday that the female shark has a red swollen eye. I'm guessing that she was injured. What can I do for her eye?
<Hi Cheryl, Jorie here.  A bit more info. would be helpful in determining what's going on - how large is this tank, what other fish are in it, what are the water parameters, etc.  With the small amount of info. you've given me, I'd guess that this is either due to an injury, or the beginning of pop-eye, a disease usually caused by poor water quality.  First thing to do is test for ammonia, nitrite, nitrate, pH, etc. - for any disease/abnormality, that's the first thing to check.  Once you've determined (if you can determine) that the water quality is pristine, then you can look further into possible injury, aggression from other fish/livestock, etc.
Hope this helps, Jorie>
Cheryl