Please visit our Sponsors
FAQs on Oscar Systems, Operation

Related Articles: Oscars, Neotropical Cichlids, African Cichlids, Dwarf South American Cichlids, Cichlid Fishes in General,

Related FAQs: Oscars 1, Oscars 2, Oscar Identification, Oscar Selection, Oscar Compatibility, Oscar Behavior, Oscar Systems, Oscar Feeding, Oscar Disease/Health, Oscar Reproduction, Neotropical Cichlids 1, Cichlids of the World, Cichlid Systems, Cichlid Identification, Cichlid Behavior, Cichlid Compatibility, Cichlid Selection, Cichlid Feeding, Cichlid Disease, Cichlid Reproduction,

Baby Oscar      11/10/18
I have two 6” Oscars in a 125 gallon I just hard reset to give them each a territory with lava rock and driftwood, caves with plastic flower pot liners inserted into siliconed rock surrounds, etc.
<Indeed; if these are two males, there's a good chance they WILL NOT cohabit in a tank this small once mature. I know 125 gallons sounds massive, but bear in mind that an adult male Oscar will be guarding a territory with a radius of some 6 feet around its spawning pit. For sure they'll sometimes ignore dissimilar tankmates, but a rival male Oscar has almost no chance of being tolerated. Observe both fish carefully, and be aware that fights can easily result in injuries that are very difficult to treat. The classic ones are eye injuries (which lead to pop-eye or blindness) or most distressingly, dislocated jaw bones. Once the jaws are damaged, usually through wrestling, the jaws never heal, and the fish starves to death.>
I have 2 HUGE canister filters and a HOB and will be building a fluidized bed sump when the rest of the parts arrive next week.
They are doing well, growing around 1.5” a month, love people (and haven’t even eaten the sacrificial plants I threw in there for entertainment). They get 25% water changes every other day and are water tested everyday. So, in short, I am a little familiar with the species. Today, while out grabbing some supplies for the house the hubby and I saw an inch and a half Oscar in a tank full of 3-4 inchers. It was in a store we all go to, but preferably NOT for fish because their tanks have a super-high mortality rate.
I knew what would happen if we left him there.
Sadly, I think we all do.
<Yes; but the flip side is plenty of animals much smarter than Oscars are bred and die on an industrial scale for human uses, such as pigs. Once you buy a pitiable fish, yes, you're saving that fish, but the retailer simply sees this as a successful sale and orders another. So while the humane act would seem to be rescuing such fish, in reality what you're doing is encouraging the overproduction of large, difficult to house 'tankbuster' fish. The logical thing to do is ignore the fish, and yes, it'll die, but the retailer won't order it again given money was lost on it. Make sense?>
So, I brought him home, knowing full well the mess of filters, water changes and probably the creepy crawlies he was bringing home. My friend owns a pet shop, so we popped by and threw together a 10 gallon hospital tank. We filled the tank with pre-heated, oxygenated R/O,
<Do be careful about making "good" water chemistry changes all of a sudden. If this beast was in hard water, slapping him in moderately or very soft water could do more harm than good. Best thing with water chemistry changes is to do them across several days.>
slapped in a filter with cycled media, air and lights (kept low to keep him calm). I set the temp to 84F and am giving him the first round of Paraguard. I know its probably stress, but he’s not eating. Is there anything I can try to tempt him with that isn’t crushed pellet, homemade frozen or pieces of prawn? Anything you think I should know about caring for a guy this young?
<Earthworms and small river shrimps are crack cocaine for Oscars, so these'd be my go-to foods. Earthworms are usually safe because they're unlikely to be exposed to water parasites. With shrimps, ideally gut-load them with flake food first. Frozen shrimp is okay, but remember it contains thiaminase, as do mussels, so long term causes serious health problems if it isn't used alongside thiaminase-free foods such as cod fillet, cockles and squid.>
(Oh, and please set your mind at ease about his future, I’ve already got a mailbox with his name on it outside the new 55 gallon tank sitting on my living room floor for this guy. �� )
Thank you so much for this site, when I first decided on Oscars, I read everything I could get my hands on, and I spent a ton of time here. I promise never to ask about the sex of an Oscar, lol.
<Indeed! Virtually unsexable.>
Thanks for all you do,
<And thank you for the kind words. Cheers, Neale.>
Re: Baby Oscar     11/11/18

Thank you, Neale for all of your help.
<Most welcome.>
Yes, the 125 could turn into an issue. I bought the two larger as a shoaling pair. As juveniles, they have proved inseparable. Of course, that can change any day as they get older.
<Precisely. Juveniles are social, even, as you say, to some degree schooling fish. Presumably this is some sort of defence against predators. As they mature, this will change, and pairs of sexually mature fish will claim territories and drive away other Oscars. Very similar to most other monogamous pairing cichlids, e.g., Angels.>
There have been some displays of dominance like lip locking, but it hasn’t happened often.
<Good. Every Oscar is different, and they're intelligent animals with behaviours that can, to some extent, adapt to their environment. So I'm quite sure that sometimes two 'brothers' end up living together more or less amicably. Just don't bank on it!>
There have been mating type behaviors, though, too… (tail slapping, rubbing up against one another and cleaning a corner of the tank floor). They still actively shoal at 6”. So, at this point, young as they are, it’s a tough call. I have a cycled empty 55 on standby (hospital tank) so if things go south, I at least can separate them.
And you’re right about the baby. I shouldn’t have bought him. I don’t want to encourage the poor husbandry. I can’t go to those places.
<Totally understand your feelings and actions. Not saying I wouldn't have done the same -- but logically, as hobbyists, we would do the fish (overall!) a service by not patronising the scummy stores, and not buying the fish that shouldn't have been imported.>
He’s still not eating, but I will keep trying.
<Oscars (like virtually all cichlids) will eat when they're ready, and not a moment before. Assuming he's not in terrible shape, I'd simply focus on giving him quiet, darkness, and good water conditions. If live river shrimp are available, by all means stick a few in the tank since they're stay alive until such time as he eats them, so won't adversely affect water quality. Otherwise, feel secure about waiting a few days, even week or two before offering meals and seeing them eaten.>
Its hard to say, Oscars are wonderful sad sacks and have a tendency to “mope” when things change in their tank.
<Precisely. It's the flip side of their high level of intelligence. Just as with any other smart animal (dog, parrot, pig) that's been abused, they're not going to suddenly eat food just because it's there. It's Guppies and other mindless fish that do that! No, with these big, cuddly cichlids you need to get them on side first. Calm them down, get them feeling secure, and train them to recognise you're not a threat but a friend. Takes time, and repetition. For example, walk past the tank, say "hello", then walk on, without causing a disturbance by turning the lights on or opening the hood. He'll probably stay hiding, but so long as he doesn't dart away in panic, then it's steps in the right direction. Soon enough he'll figure out you're harmless, and since Oscars, like Goldfish and Koi, genuinely enjoy human company, he'll start seeing you as a friend and come to the front to see what's going on. Once that happens, offer a small, tasty meal. Bit of white fish fillet, an earthworm, whatever. Only a tiny bit, because it might not be eaten, and whipping out a net to remove multiple or large chunks of uneaten food will terrify a nervous fish. I find a turkey baster a great tool for removing small bits of food in a discrete manner.>
Or they don’t get the food they want. Or they haven’t seen you in a day. Or if its Tuesday. He was swimming around this morning, but has gone back into hiding during the day. My guess is he is trying to be sure there is nothing in his tank that would eat him. I tested his water, offered him food and left him alone for the most part. I will continue to offer food.
Thanks again!
<Hope this helps, Neale.>

Am I being a jerk? Oscar sitting     10/23/17
A friend of mine is going across the country (from Idaho to Virginia) for a training program with the company she works for. She'll be gone for about 6 months and has asked me to take care of her Oscar fish while she's gone. I told her I'd come by her house and feed, spend time with, and do the water changes while she's gone (this fish is beautiful, tons of fun, and very people friendly.) She said no, that she wanted to bring him to my house because she is not going to keep the home she currently rents while she's gone. I told her ok, I'd make room for his 125 gallon tank and we'd bring the fish, the tank, the water, etc. over here while she was gone. She doesn't want to do that, she wants me to put him in one of my tanks and put her tank in "storage." I told her the only tank I have that is both open (no fish in it) and cycled is a 55 gallon with a Cascade 700 canister filter on it and that it wouldn't be big enough for her fish (close to a foot long). She insists that for 6 months, that it would be alright, but from the research I've done on your site, I believe she's wrong. This tank is too small for this fish even for 6 months. I got angry (mostly because I believe this is her sneaky way of dumping a fish on me that I'm not prepared to care for well) and told her no.
Was this appropriate or am I being a jerk?
<Mmm; not a jerk. Asking to do a favor... and offering to do so; per your understanding of the needs of this Oscar. It could be kept in the four foot long 55... barely; by being careful re feeding, doing water changes
weekly/religiously... But if there's trouble, like a power outage; there could be a disaster. I'd ask that she allow you to set up her tank, use it for this half year. Bob Fenner>
*Renee *
Re: Am I being a jerk?    10/23/17

Ok, I'll try again to get her to bring the tank over with him, but she was pretty adamant she didn't want to do that (said she didn't want the "hassle"). The 55 gallon that I have open was, until two days ago, inhabited by my axolotls (I found them new homes because I was struggling to maintain their water temperature - and failing.) I
haven't cleaned the filter since they left, but it was cleaned at the first of the month. I know very little (ok, nothing) about Oscars, but is there any chance of the Oscar be affected by residual waste from the axolotls if I do a 25% water change and clean the filter before the Oscar arrives?
<I would change most all the water out here via gravel vacuuming.
Oscars/Astronotus are VERY tough/hardy>
They were healthy and fine before they left. This fish is such a great animal, he loves to be petted, eats
from your hand, fetches plastic cat toys you throw in his tank, just really special. If I'm going to do this, I want to be sure he'll survive me!
<I have high confidence in you. Bob Fenner>
Re: Am I being a jerk?    10/23/17

I always put 2 ml of Stability in my replacement water when I do water changes, so how much water do you think I can remove without crashing the biological filter in the tank?
<Likely most all of it. I would add all the transfer water from moving the Oscar. B>
Re: Am I being a jerk?    10/23/17

Oh, of course! That's brilliant, thank you!
<Welcome Renee. BobF>

125 Gallon setup; FW; Oscars and more       2/24/15
Hi guys!
I just found your website recently - awesome treasure trove of information!
<Ah yes. Good folks, and been at this for a while>
I've been poking around doing research but have been finding vague or conflicting information so figured I'd ask the experts!
I got back into having fish in late September after I'd found a really decent 55 gallon with stand/etc. for free near my parents house while visiting. My current setup is using an API Filstar xp medium, Eheim heater and LED lights. I've got two tiger Oscars (one albino), a black diamond cichlid and a Pleco. They're all under 7 inches though they've been growing well. I'm planning as tax refunds approach to get on finding them their upgrade tank and am planning to go with a 125.
<Nice; and needed!>
When it comes to stress they have lots of hiding places and have great color, though they're the first Oscars I've had, having had them in the past, that are more skittish than curious so I'm not sure if it's just personality or if there may be something else going on (the black diamond is always ready to come up and eat when I tap my finger in the tank - the Oscars are a 50/50 chance if they respond or wait until I'm gone).
<"Just" natural behavior.... and a real NEED to get into more space>
It's a big assumption, but their pelvic fins are developing *very* differently and they stick together like glue 24/7 so I'm questioning if I may have a male/female pair (I know it's not really possible to sex visually, just how protective the larger is of the smaller one rather than getting territorial). The Pleco really could care less what's going on most of the time - he will just keep under his driftwood piece except for occasionally charging around the tank at high speed. Overall the tank seems pretty
healthy right now. With the size of the tank versus the fish I'm making sure to really keep on top of water changes and using me Eheim gravel vacuum (which is the best $40 I've ever spent, I wish I'd had one when I worked in pet stores).
I just wanted to reach out and see if you had any feedback for this type of tank that I should keep an eye on when I upgrade?
<Is a good shape, size for what you have now>
I've read a number of places that two canister filters are a good idea - I'm planning on buying  a Filstar XL, so could keep my medium as backup?
<I'd run both>
But I'm not 100% when sites say a secondary backup filter is needed for 125's whether they just mean in case one breaks or that both should be running. What's a desirable flow rate for a 125 gallon tank with somewhat messy fish?
<Really.... ten times plus turn over... what you have are very messy fishes>
I'm loving having fish again and want to do everything I can afford to do to make sure these guys all stay happy and healthy and reach their full football size! Few things as cool as full grown Oscars in my book (except maybe for clown knives).
Any suggestions greatly appreciated!
<Keep curious; reading, dreaming, and moving forward! Bob Fenner>
Re: 125 Gallon setup      2/24/15

Thanks for the quick response Bob!
When you say 10x plus turn over what would that look like? 125 gallons x10 - I'm assuming that's per hour?
<Ah yes>
And as long as it's not massive overkill it probably doesn't hurt to go more than needed right?
<You are correct!>
<Welcome. BobF>

Thinking of an Oscar tank     09/11/14
Hi Crew
Hope you’re well.
It is possible that I will become the owner of a custom 10ft tank with a capacity of approx. 2500L (660 gallons). I have a long term plan for this tank. I’d like to decorate with logs of driftwood, stock it with 8 clown loaches and a Pleco and grow them up to a good size (well, well over bite size - maybe 15-20cm - understanding that this could take a long while).
<Mmm; less than you might think IF you feed good foods often, do regular partial water changes...>
Once they’re grown I’d add 4 small Red Tiger Oscars and grow them up too. Firstly, does that sound like a reasonable strategy and mix of fish? Overstocked or ok?
<Not overstocked at all... I'd be thinking of other Neotropical cichlids to add as well>
By way of background, I’ve kept fish for years and had a variety of tanks, including African cichlids, but no direct experience with Oscars. I had a pair of Blue Acaras in the past and adored them for the most part. The negative (for me at least) was their incessant breeding! They became territorial and destructive and the female took a bit of a beating once in a while. I also ended up with literally hundreds of fry, which I ended up growing up in various tanks around the house. For the short short spells when they weren’t breeding, they were, however, quite peaceful.
I have done a lot of research on Oscars, but have found some conflicting information and I’m wondering if you can help me with the following questions:
1. Is it cruel to keep an Oscar without a mate? That is, will they die sooner or not be at their best?
<Not cruel at all... and many "hybrids" (reds, Longfins...) tend to be sterile (and sterilized)... so their likelihood of breeding is greatly diminished>
2. Assuming not, if I could manage to have a tank with Oscars of the same sex, is it going to be more peaceful? Understand that they’ll ‘rearrange' things, so this question it’s more about aggression/territorial behaviour.
<Hard to impossible to sex Astronotus at four inches in length. Not easy even as adults... depending on how they were raised mostly>
3. What is the minimum size an Oscar would need to be to be vented?
<Oh! Still not easy at all to do... six inches or more>
I have no experience in venting, but I’m hoping someone at my local fish shop does.
<Doubtful. Most folks rely on behavior, longer unpaired fins length, the exposure of breeding "tubes">
4. Will Oscars and Plecos destroy Marimo balls?
I know it’s an odd question, but I thought the Oscars could entertain themselves with them! I’m trying to pre-empt boredom.
I thought I’d ask these questions before I start, so I can be prepared…and it also means that this question is not at all urgent, so no rush on your answer.
Thank you in advance for your time and assistance.
<I do feel compelled to encourage your further reading, consideration for making this display a thematic biotope presentation. Is what I would do... set upon a plan to stock with organisms occurring in a given place, habitat. Bob Fenner>
Re: Thinking of an Oscar tank      09/12/14

Hi Bob
Thanks so much for your advice and I’m now rethinking my approach.
<I'd really like to see you do so... Perhaps some large Discus, Prochilodus.... a mix of medium sized catfishes; some peaceful cichlids like Festivums... Some tall plantings... >
Gone back to the drawing board and looking at a biotope set up featuring Oscars - found this resource: http://fish.mongabay.com/biotope_whitewater_amazon.htm. Thinking now about 6 Oscars (perhaps different colour variations), 8 spotted silver dollars and will continue researching into other/alternative appropriate choices.
<Sounds great>
I like the idea of simplicity and limiting the number of different species, but will keep researching. If you happen to know any good resources on this kind of biotope, I would sure appreciate a link or any suggestions that you have.
<Some of the German aquarium product manufacturers have fab books, websites including biotope suggestions... The works by Heiko Bleher are all worthwhile>
Thanks again for your help.
<Sure! BobF>

Oscars, sys f'     2/6/13
Hey crew, first time Oscar owner, but long time aquarist.  Stumbled across your website and was amazed at the plethora of good info and amazing pics. I have 3 tigers and 1 albino tiger all 1.5" long in a 55 gallon tank, i know it's too small for 4 Oscars
<Yes… four times too small. Even a singleton isn't really suitable for 55 gallons.
I assume you mean 55 US gallons (208 litres/46 Imperial gallons). Long term, plan for 75 gallons for the first Oscar, and then something like 50 gallons for each additional specimen. The problem isn't so much space as volume of water; in 55-gallon tanks Oscar pollute the water so quickly nitrate levels go up very fast, and continual exposure to nitrate above 20 mg/l is a common cause of sickness (especially Hexamita infections and Head and Lateral Line Erosion). Since these are very difficult and expensive to treat, it makes much more sense to use a bigger aquarium to keep nitrate levels low, so you prevent the problem in the first place.>
but i have a local store that will trade tank mates or food for a couple when they turn adolescent.  They're more like vicious little puppies right now, always excited to see me.
<"Vicious" is a curious way to describe puppies.>
I watch for at least an hour a day.
Now to my question, i have all live plants (weighted down),
<Probably won't last for long once these fish become sexually mature.>
and some pretty large decorations to accommodate a larger fish, they all seem to have fun hiding in various places, but i was wondering if i need to install a larger shelter/cave for the 2 I'll be keeping as they mature.
<Not really. Astronotus spp. don't use caves as such. They're open spawners, meaning they find an area that's sheltered, dig some sort of pit, and lay their eggs there. In other words, they don't care about caves. Subdued lighting and perhaps floating plants, yes, those are good. Tall bogwood roots are a plus as well. But caves, not so much.>
I've attached a photo of the tank.
Any advice would be great, great website! :-)
<Thanks for the kind words. Cheers, Neale.>

RO/DI waste water, Oscar sys.     1/14/13
Good morning
I have BRS 75gpd 4stage ro/di system for my 125 gallon fowlr. I also have a 75 gallon tank with 1 Oscar , I heard I should not use ro/di in the Oscar tank.
<Mmm, likely yes; Astronotus live well enough in most potable waters of moderate hardness, alkalinity... pH. What is your tap water like?>
 My question is should I use the waste water or just tap water with a dechlorinator when doing water changes to the Oscar tank?
<Again; likely the latter, depending on its water qualities. The vented "waste water" from the RO/DI may be useful... but I'd use it on plants. Bob Fenner>

Oscar Systems Question (and test strips vs. drops)   4/1/12
Hello. First I would like to start by thanking you for your website and the devotion you put behind it to help other fish owners as myself.
<And thank you for these kind words.>
I own 2 tiger Oscars, that are unfortunately crammed in a 30 gallon for the last few weeks, and I finally purchased a used 75 gallon tank.
<Ah, good.>
I had to purchase a new canister filter (Fluval 306), and I have been cycling for 2 weeks.
<This is an excellent filter. But I do think it'll be overworked on an aquarium this large. While the Oscars are juveniles (say, up to 12 cm/5 inches) you should be okay, but above that, this filter may not be able to provide adequate biological filtration (i.e., ammonia removal) or mechanical filtration (i.e., water clarity). You will likely need to add a second filter of similar size to this system.>
I originally purchased Nutrafin Cycle, and added the appropriate dosages over 6 days. The information on the bottle said my water would be safe in 3 days (which I found hard to believe), but after testing my water, my nitrites were still higher than my nitrates.
<None of these "instant cycling" products is terribly reliable. Sometimes they work, and sometimes they don't. In any event, I do think your filter may be overwhelmed.>
A friend recommended I use Microbe-Lift Special Blend, and upon adding 2 days ago, my nitrites rose and leveled off at about .75 ppm and my nitrates at about 15 ppm.
<What's the nitrate level of your tap water? If your tap water has a nitrate level of well below 15 ppm, e.g., 10 ppm, then the filter is clearly doing its job, turning ammonia into nitrate. But if your tap water has a nitrate level of 15 ppm, then the filter isn't producing nitrate yet, so cycling is still ongoing.>
I am getting anxious to put my Oscars in their larger tank- as I know it must be terrible in the 30 (although water quality in the 30 is flawless.)
<Understandable anxiety.>
Do you think it would be safe to add 2 large Oscars into this new environment, or should I wait for optimal water quality.
<See above.>
Also. a side question, which water testing process do you prefer: paper test strips or liquid drops with the vials. I tend to get different readings from each (although in the same ball park). Thank you for your time and your website! Craig.
<Six of one, half a dozen of the other. Drop test kits are generally more accurate, but because they're fiddly, people use them less often, and you need to do separate tests for each parameter (nitrite, pH, etc.). Strips are easy to use and if you slice them longitudinally, you can get two tests from each strip. So people often use these much more regularly because they're quick and cheap, and the multi-test strips provide you with lots of information in a single test. At the end of the day, the best test kit is the one that used. Cheers, Neale.>

Oscars, beh., sys.    3/30/12
Hi guys. Long time user of your site. I have read many of your forums about Oscar issues and I am not a first time owner but I am somewhat stumped here. I currently have five oscars, about 5 inches, in a 65 gallon tank.
<Hmm… a bit small.>
Their 295 in currently cycling, ready in a few days.
They were all bought together except one special one who I found by accident and couldn't resist. There are two tiger oscars, two albino tigers and one almost solid black with tiny bits of red on this gill and the "eye" on his tail. The water parameters are great, temp around 75-76. They eat a huge variety of pellets (sinking and floating) flakes, earth worms, beef heart and blood worms.
<Good so far.>
One time I folded and let them eat guppies from my guppy tank and 30 Rosie minnows.
<Not the smartest thing you've done in your life. Please, don't give Oscars live feeder fish. It only takes one feeder to introduce a parasitic or bacterial infection.>

They each have their own cave and are starting to pair off. Two of them fought on and off for two weeks, probably establishing a chain of command or something. They are all friendly now, they sometimes swim behind each other and suck another's fins into their mouths and rub on each other (which I never saw my other ones from previous years do). But over all they are friendly.
Now my problem. Sometimes recently they swim crazy around the tank.
<As they do, when confined. Bear in mind adults in the wild will hold territories some metres across, so even a big aquarium is a teeny-tiny volume of water so far as their instincts go. Sure, these have been bred in captivity for decades, but the instincts are still there, to some degree.>
Usually only one or two maybe (it's hard to tell with so many in there) and the others try to stay out of the way. Then they hit a wall or rock and float to the top, take some labored breaths and go back to normal. I thought it was bad fighting at first ending in an all and all brawl to the death where one was fleeing. The more I watched it this strand activity seems to happen out of the blue, nothing to start it, it lasts for ten seconds maybe, and mostly at night right before or after I turn off the lights. They seems unharmed, maybe a scratch or something but nothing bad. I change the water about 35% every weekend or every other weekend and filters every weekend. I have a Tetra Tec filter with the heater inside it so the oscars don't break it playing around and a small inside pump that circulates water inside (I have seen in saltwater tanks) I have Malaysian driftwood, slate, and java fern in the tank.
I was thinking maybe it was electrical but I frequently put my hands inside the tank and haven't felt anything. They seem fine during the day which is odd. Besides rough playing and mocking each others movements they don't fight or hurt each other. They are in a high traffic area as far as kids running up to see them.
<Ah, now, this could either scare them (low-frequency sounds and vibrations) or distract them (the promise of food). Either way, a factor.>
But they seem to love the attention. What ideas might you have here?
It sort of reminds me of the spinning type of death that happened to my discus when i had them. That was years ago and a different house, different tank and water type. They would freak out and dart around the tank hitting everything until they died. After I had them several years and introduced another one from a friends tank. This is what has caused me to write. The oscars were about an inch when I got them 6 months ago.  Any help would be great. I am still leaning electrical but am not sure cause the heater light isn't on when they do it.
<Do think things will become more normal in the larger tank, so wouldn't worry too much right now. No obvious problems, at least. Cheers, Neale.>

New Oscar Tank    3/12/12
Hello Crew,
    I am in the process of setting up a new 135 gallon (long) freshwater tank. I plan on keeping one Oscar and some compatible tankmates, probably a few Silver Dollars. My plan is to set up a wet/dry filter in a sump.
<Mmm, do monitor/watch your Nitrate accumulation... keep under 20 ppm>
I understand Oscars can be quite messy so I plan on turning over the tank 10X per hour. I want to purchase a Glass-Holes 1500 GPH overflow kit, and a Supreme Classic Mag Drive 18 (MD18) for return. I have 4 feet of head so the pump should put me slightly above 10X tank volume per hour (1375). My concern is that the pump only has one 3/4 inch output for return. Would one 3/4 inch return line work efficiently, or would you recommend I purchase two smaller pumps (Mag Drive 700's, which only have 1/2 inch outputs)? Or can you recommend a different pump?
<I'd supplement water movement inside the tank w/ internal pumps... Hydors, VorTech's or such. Search re on WWM>
I'm on a fairly tight budget, but I don't want to cut corners on this system.
<The Hydors then: http://www.wetwebmedia.com/HydorKoraliaPF.htm>
Any advice would be greatly appreciated.
Thank you for your time.
<Welcome. Bob Fenner>
 P.S. I want to thank all of you for putting so much passion and dedication in to keeping such a tremendous website.
Re: New Oscar Tank   3/14/12

Thank you Bob for your quick response,
     Just when I think I have this all figured out, you throw me a curve ball. I never really thought of using powerheads in a freshwater application. How much of my overall volume (1350 GPH) should I substitute with internal circulation?
<I'd say half or more>
Could I get away with  700 GPH to my sump/filter, and 650 with powerheads?
 Sorry to be bothersome, but now I feel as though I need to approach this whole setup differently. I want to build my own wet/dry because the setup seems easier to maintain, and easier on my wallet than a canister filter.
<Understood. Do keep your eyes on nitrate accumulation... as a window to how your water quality is doing. Keep under 20 ppm>
Thanks again for your time
<And you for yours. BobF>
Re: New Oscar Tank   3/14/12

Will do, I plan on doing regular small water changes, around 20% every two weeks. I don't think there will be a large amount of livestock in this tank, but again, I understand Oscars have quite a large bioload. I understand silver dollars can get fairly large as well.
<Some species>
 I am still in the planning phase, and still haven't quite made up my mind as to what kind of tankmates I want to put in with this Oscar.
Thanks for all your help and advice
Have a good rest of your day
<And you. B>

my cichlids... no, info., rdg. 2/6/12
I have a question, we just started our tank up about a month ago, we have all the levels and temperature good.
<Meaning what? I need numbers, not adjectives. How big is the tank? How did you cycle the tank before adding the fish (cycling taking some 4-6 weeks to mature the filter). What is the current ammonia and nitrite level? What is the temperature? What is the water hardness and pH?>
We bought 2 albino cichlids, 2 tiger Oscars, Plecostomus, and an orange south American one sorry don't remember the name.
<Hope this is a big aquarium. The two Oscars alone will need some 100 gallons to get along; with a bunch more random cichlids, 150, 200 gallons is more like the minimum. Stick them into something ridiculously small, like a 75 or God help us a 55 gallon tank, then these cichlids will eventually beat each other up. Mother Nature has little interest in budget or space limitations -- cichlids need bucket-loads of space, and if that isn't provided, they kill one another.>
So my question is I have one albino that hangs on the top in the corner by him self, he rarely ever leaves the corner. I do see the orange one likes to bully in the tank,
what do I do if he has a bad fin, since I don't see him swimming around?
<Need the relevant information here before I can say anything beyond the obvious.>
Thank you, Margaret
<Glad to help. Cheers, Neale.>

My Dirty Fish tank! Oscar sys. 10/4/11
Hi guys, I did a Google search earlier and found your website, but it didn't answer my particular question. So I am still hoping you can help. I have a Tiger Oscar And I'm sick of changing his water every week!
<Unfortunately, it's what you have to do.>
It's just him and a crayfish in his tank with minimal decoration,
<Crayfish are Oscar food; you do realise this?>
I have two filters, an airstone and a heater in there, as well as a fluro light on top. His tank just gets so filthy all the time, the water turns so green and the glass gets so dirty that I cant see him which is a shame because he is such a beautiful fish, I mentioned this to my friends and they suggested I get a Sailfin Pleco as they have one and it keeps their tank really clean,
<Your friend has no idea what he/she is talking about. Adding another fish CANNOT make an aquarium cleaner. By definition, a second fish produces MORE ammonia and MORE faeces, so the aquarium gets DIRTIER FASTER. Think about the logic. The reason your aquarium gets filthy is likely a combination of these: the tank is small; the filter isn't sucking up the faeces quickly because it's too small; the filter isn't cleaned often enough; and the Oscar is fed too much.>
but I'm not sure if my Oscar will kill it or not? If that is the case, could you suggest anything else? I change his water and within a day or two it is green again.
<Let's say you have a 55 gallon tank, a popular size for aquarists who think they want to keep an Oscar. This aquarium is far too small for an adult Oscar, and dirty water is inevitable. Keep your Oscar in a 200 gallon tank, and you'd need to do fewer water changes because [a] the water would stay clear for longer; and [b] your nitrate levels would stay below 20 mg/l for longer. If you have a 55 gallon tank, and don't want to keep changing the water, then the answer is this: Don't keep an Oscar. If you don't want a messy house, you don't keep an Elephant! Same here. Something small and clean, like a nice school of Neon Tetras might be just the thing��>
Please help!
Regards, Rhi
<Do read:
Cheers, Neale.>

Oscars; sys., fdg., hlth. 7/14/11
First off I'm new to Oscars and have learned TONS from the posts on your site. I have 3 juvenile Oscars. The largest 2 are around 4 inches long. I bought them because they looked cool and I had seen a friends very gregarious Oscar and thought how much it reminded me of my black lab.
So being the typical exuberant "act first and research later" Oscar owner, I bought 3 of them. Doh!
I have 2 albino's and a tiger. Originally they were all in a 35 gallon aquarium together, but later I built a new 65 gallon and moved the tiger to it along with several new jacks, auratus and a couple others.
<One Oscar will not live long or well in a 35 gallon system>
The tiger was the largest of the fish in the new aquarium and everyone has gotten along famously for several months despite significant size differences. Mistakenly I have been feeding goldfish to my various cichlids... soon to stop thanks to what I have read here.
I have been keeping the gold fish in a separate aquarium that remains heavily medicated with elevated temperatures. None of my fish have shown any signs of parasites or disease and I check them daily.
<You won't be able to see... until there are REAL problems>
The 2 albinos are still in the 35 gallon and seem to get along fine despite a significant size difference between them.
<Antagonism will occur very rapidly...>
I checked the water a couple of days ago and the nitrite/nitrate/ammonia levels are fine, but I clearly need to change the water more often.
<I'd change a good percentage every week. See WWM re>
The filter is a 55 gallon filter in a 35 gallon aquarium so it does keep ahead and I clean the filter every week or so. The 65 gallon aquarium has a 120 gallon aquarium filter in it so it too keeps ahead and the filters get cleaned at the same time as the smaller aquarium.
OK for the problems...
1. The albinos are in the 35 gallon aquarium. The larger albino for several months has randomly exhibited the odd behavior of being placid and calm for days and then suddenly slamming himself into the glass, bottom or lid.
<Due to the size/volume, and/or possibly a (goldfish vectored) parasite.
These fish need to be moved (now) to larger quarters. Read here:
It then acts like it has knocked itself out and will lay on the bottom on it's side, breathing heavily. A few minutes later it's swimming around like nothing ever happened. The albinos will obviously soon outgrow their current home, but have never conflicted or caused each other any harm. Is the large albino crazy?
<Mmm, no>
The slightly smaller one NEVER acts that way. Some times this will happen in the middle of the night when I am asleep and the thrashing around noises are so significant that it wakes me up.
2. The tiger Oscar was in the 65 gallon aquarium and has been a great fish both to me and it's tank mates. It has been in a static environment (no new fish or other changes) for several months with 4 jacks and 3 auratus and a pleck
<These fishes also need a much larger world...>
of which all are smaller than the Oscar by half. This past week the Oscar stopped eating and being gregarious and then killed an auratus and started doing the random slamming into things. It currently has a deep gash in it's head. I know it wasn't the best of solutions, but I moved it back in with the other Oscars to save the other fish. The three Oscars for the past 3 days of being back together are getting along very well despite the aquarium size. The large albino and the tiger are the same size and never apart and swim side by side or lay on the bottom together. They never fight and completely ignore the smaller albino. None of then show any territorial signs...yet.
Any suggestions would be helpful.
<As you re-read the "Oscar Health/Disease FAQs" files, you might consider a mixed treatment of Metronidazole and an Anthelminthic (in foods), otherwise, STOP feeding "feeders" and oh, I see some good news below...>
Obviously these guys need much more space and I intend to build a 300 gallon in the next 6 months, but they wont wait that long.
<Likely not>
I have an empty 55 gallon that I may split them up in until then.
<A good move>
I'm concerned they will
kill themselves slamming into things. Is this remotely normal?
<Yes... from crowding, certain parasitic infestations>
Can I do anything about it?
<Read where you've been referred to>
I already removed anything from the aquarium that they could bash into the glass for fear of them hitting the glass and breaking it. Thank you in advance for your input.
<Welcome! Bob Fenner>

Oscar Fish Acting Crazy 3/11/11
<Hello Dominique. You appeared to send a message with 16 MB of images attached, each more than 2 MB in size. Because of the limited e-mail space we have here, and because us crew members don't want to spend all evening downloading giant attachments, we don't accept that size attachments or that number of them. We do specifically state this on the "Ask WWM" page, likely where you found our e-mail address. Please resend your message with a few, smaller images. Programs like iPhoto will easily resize images. Try aiming for about 800 x 600 pixels, or about 500 KB per photo. Thanks, Neale.>

Re: Oscar Fish Acting Crazy [Fixed]... sys. 3/11/11
Hello Crew,
I tried to find an area on the website where I could post my question but I could not seem to locate it. I am e-mailing you guys today because I am concerned about my Oscar fish's behaviour. As well as awkward things happening to my Pleco.
<Okay, fire away!>
To start I have a 65 gallon tank with a 300 watt heater.
<Should be ample for a single Oscar, or a single adult Plec alongside small community fish, but Oscar and Plec together will need more space than this.
Even if water quality stays acceptable, I'd expect a fair amount of silt in the tank, reducing its clarity, and making it altogether less attractive.>
I have two Emperor filters which claim to filter 55 gallons each.
The tank contains 7 fish in total.
2 Oscars (1 is a red Oscar and the other is a albino Oscar)
<Yikes! If these are both males, you won't be able to keep them together in a tank this small.>
2 Zebra Danios (There use to be 3 but one disappeared last month)
<I bet! Zebra Danios are Oscar food. They shouldn't be in the tank at all.
While a single or even three Danios won't poison an Oscar, they are minnows, and that means, like Goldfish, they contain thiaminase, and over the long term that will cause problems. In any case, there's a risk of introducing disease, and simply by giving predators like Oscars live food, you increase the chances they'll become aggressive. Remove to another aquarium, ASAP.>
2 Fire and Ice (This is the name of the fish given at the pet store)
<Need a photo of these.>
1 Leopard Pleco
<Pterygoplichthys gibbiceps; a very, VERY large Plec with the potential to reach 60 cm/24 inches within three years. Sometimes Plecs damage Oscars by scraping at their flanks. I would not keep Oscars and Plecs together, but if you must, do look out for signs of damage on the flanks, like odd white scratches.>
The fish generally get along together. I have not seen them fighting with each other.
<Yet. Sexual maturity in Oscars occurs around 20 cm/8 inches, from which point males become increasingly intolerant of other males and sometimes females.>
The Oscars swim together regularly and are usually found floating beside each other.
<For now. While Oscars *are* comparatively peaceful by cichlid standards, they are *not* schooling fish. Some specimens coexist indefinitely, especially in large (100+ gallon) tanks. But there's always a risk, and mouth wrestling is a good sign they aren't getting along. Prolonged aggression leads to shredding fins, stress, and worse.>
The weird behaviour I have noticed with my albino Oscar is that whenever I walk into the room, turn the room or tank lights on or even open the top lid of the tank he will begin to swim as fast as possible into any decoration then right into the glass side of the tank and finish off by swimming directly up and hitting the top of the tank.
<Stress, alarm.>
Afterwards he will just float on his side at the top of the tank for a couple minutes and have multiple cuts and scratches on his head. This has been happening for the last couple of weeks and its really beginning to worry me. The red Oscar will sometimes swim away from the albino while he is having his fit and cut himself as well. So I'm left with both Oscars cut sometimes. I am just wondering why he is acting this way. Also my red Oscar is not black. When I purchased him his back was black but after a few weeks the colour has turned pale.
<Indeed. He is trying to blend into the background, but can't.>
I would like you to note that I did not know that I should wet the food pellets before feeding the Oscars since a couple weeks ago. Prior to knowing I would just throw the pellets in, this would have occurred for about 2 months. During which the albino would float on his side occasionally but he seems to be doing better now.
The other thing I would like to ask you is why is my Pleco miss coloured.
He has some dark areas and along his back in a symmetrical shape he has these brown areas and it looks weird.
<Again, altering colours to blend in.>
Sometimes his fins will split as well.
<Could easily be damage by/from the Oscars.>
I have attached some photos of my tank and fish in this email. I am doing a water change tomorrow. The red cup in the tank has saltwater in it to help heal the wounds. If it is possible could you recommend what decorations I should keep in my tank and what I should remove?
Thank You Very Much!, Dom
<Bottom line is that your aquarium is terrifying your fish. Why? Because of the white substrate. Fish HATE white substrates. Think about it -- in the wild many predators attack from above, like Herons. The brighter the substrate, the easier the fish will be seen. So fish prefer to swim over dark substrates. If you stick a white substrate in the tank, you're making your Oscar feel like it's in full view of any passing predator. End result -- constant fear. Replace with plain vanilla gravel or, if you must use something trendy, matt black gravel. Providing some overhead shade, for example floating Indian Fern, will help as well. Problem solved. Cheers, Neale.>

I had two Tiger Oscars this morning. Tonight when I got home, one was gone. 2/25/11
<Oh no!>
My husband saw Rosco, (the missing Oscar) when he went to feed them, but when I got home he was gone. Rosco was about an inch smaller than Neko (the Oscar still in the tank), is it possible that Neko ate Rosco, even at his size?
<Sounds unlikely.>
There's no other explanation for my missing Rosco.
<My first guess is a jumper. Check under all the furniture. They can flop a long way after jumping and are likely to jump out of a tank that is stressing them. They can push open the top if they hit it hard enough.>
I got them both at the same size, but Neko grew more, and faster. I tried separating them and feeding them, but Rosco still didn't grow very fast. what did I do wrong?
<Many factors can cause different growth rates. Genes, exposure to chemicals/meds...>
My second problem is that Neko is now turning colors. He's in a 90 gal tank and I did change the water yesterday and treated it as well.
<Treated with what?>
I have already changed half of the water in case treatment was what was wrong. How long will it be before can I see an improvement in his color and behavior. <Until whatever is stressing him is corrected.> I don't know when to start worrying. <Now.> I lost my Oscar that I had for 11 years due to the shock of moving, and now Rosco, and I really don't want to lose anymore. please help!
<Check water parameters asap. You don't mention any water testing. Nitrites, ammonia, pH. If you don't have test kits, take water to fish store. Something is not good in the tank. Changing a lot of water can be stressful. If you are cleaning too thoroughly and removing a lot of beneficial bacteria from filters or substrate, could cause an ammonia spike. Here is a place to start reading on nitrogen cycling and testing your water. much to read from links there...
http://www.wetwebmedia.com/FWSubWebIndex/fwn2cycfaqs.htm >
thank you!
<You are welcome!

Need urgent advise about my Flowerhorn... hlth., env. 9/12/10
Hi Team,
Thank You in advance for any help / advise you can provide about my ailing Flowerhorn. It has been about 20 days since my flower horn ate food and it has been lying at the bed of the tank. I was out of town before that and
hence the water was dirty by the time I could come back. I guess it is suffering from some infection. I saw the FAQ section on your website and tried a few things but it still looks sick and hardly moves around.
I have been changing water every other day since then and I have ensured it is at half the normal tank capacity. I was advised to use tetracycline (Resteclin 250mg). I also tried a TREATING REAGENT FOR INTERNAL PARASITE and 3rd Generation Yellow Powder for external infections but none of these are working. The size of my tank is about 2.5 ft by 2 ft. Tank capacity when full is about 75 liters. I have a filter which is also clean and a heater which is on 24 hours and is set at 28 Celsius. Would be happy to provide more details and pictures. Kindly advise at the earliest.
<Hello Supreeth. The simple answer is this: your aquarium is too small, and your Flowerhorn is dying because of poor environmental conditions. Medication is not going to help until you fix the living conditions. Start by reading here:
For a single adult Flowerhorn cichlid you will need at least 250 litres/66 US gallons. A juvenile might be kept in a marginally smaller tank, perhaps 180 litres/50 US gallons until it is about 10-12 cm long. You also need a very robust filtration system; I would recommend a large external canister filter such as an Eheim 2217 (1000 litres/hour turnover) or equivalent.
Water chemistry must be hard and alkaline; aim for 10-20 degrees dH, pH 7.5-8.0. Water quality must be good: 0 ammonia, 0 nitrite, less than 20 mg/l nitrate. Water temperature around 25 C/77 F. Unless you can guarantee
all of these things, your Flowerhorn will die. An aquarium that contains 75 l/20 US gallons is best used for small community fish: Neons, Danios, Corydoras, etc.
They may not be "auspicious" or "lucky" but at least they'll stay alive.
Cheers, Neale.>

Oscars... hlth., sys., �� 4/4/10
I have tried everything but I am at a loss.
<I hope to help.>
I have two tiger Oscars they are about 4 or 5 years old now, one has always been very healthy and strong the larger of the two, the other has not.
<Is this a mated pair? Especially if it's not, there's a good possibility that the larger and stronger one is larger and stronger due to beating up the smaller, weaker one, who remains smaller and weaker because he's constantly stressed and beaten up. Especially in the small tank you had them in (way too small for two adult Oscars), the chances of one bullying the other are very strong.>
I had them in a 200 litre tank, which I cleaned 30% twice a week, the weaker one got HITH but I changed their diet ( I feed them a tablet cichlid food, shelled peas, greens, frozen shrimp/ bloodworm etc) and treated the tank and it went away. I have moved them both to a 360 Litre tank,
<Still really is marginal for two adult Oscars... I would hope to see two adults in something around 125 gallons, both for the volume it offers, and therefore, better dilution of waste, and for each to be able to establish a territory and lessen problems with fighting.>
I feed them the same way, I clean the tank 30% once to twice a week (is this enough?) I am treating the tank with my usual water conditioner and now a nitrate reducer as they are quite high.
<If you're using a Nitrate reducer, then you're not cleaning enough. You should augment your maintenance in such a way that Nitrate is below 20 at all times. This is where a larger tank would come into play -- more volume means less concentrated waste, lower Nitrates. Bigger, more frequent water changes would lower Nitrate.>
The weaker Oscar seems to be sick again! His ribs on one side are poking out, it doesn't look like swim bladder ,
<Are you sure it is his ribs? Could it possibly be some sort of obstruction which has caused food to "build up" in the digestive tract, creating a lump? Can you provide numbers on Ammonia, Nitrite, and Nitrate in the tank? You're feeding a good variety of dried and wet foods, so I'm not thinking this issue is due to feeding, but could very well be due to water quality. I would get Nitrate to where it should be (mentioned above), and then add Epsom Salt to the tank in the amount of two tablespoons for every twenty gallons. This will aid in digestion and help with constipation, if that's what's going on. Overall, a system for two Oscars would be in the range of 125 gallons, employ filtration which turns the tank's volume over 8-10 times per hour, and large water changes would keep Nitrate below 20.>
he is swimming fine and eating fine, other than the one lumpy side he looks and acts like a healthy fish. Any ideas?
<I hope this helps. Please do write back if you have further questions.
If you do write back, would you mind attaching a photo of his "bad side?"
In any case, if this is swelling due to some sort of obstruction, hopefully the Epsom Salt will help him pass it. I would feed only the wet foods, and avoid feeding the dry foods, until this problem subsides. I'm sort of ruling out the idea that this lump is his ribs, but a photo would obviously help. What type of substrate are you using? I'm hoping this is just food, and not gravel.>
Tank you for your time
<Either a typo, or a funny pun! Either way, I'll leave it in... again, please write back if you have any more questions.

Oscars, Tank size, Tank mates
Creating an Oscar Tank 2/4/2010

Hello everyone, and thank you for the excellent advice as always. I'm thinking of buying a 125 US gallon tank to put tiger and albino Oscars in (Moderately planted with plastic plants, caves, Fluval canister filter, 77 degrees Fahrenheit, driftwood). Do you think six specimens would be reasonable, without fighting and overcrowding?
<The overcrowding may not be a problem with proper maintenance, but the fighting issue may be out of your hands. When you buy six cichlids you have a 98% chance of getting a breeding pair. When these fish pair up and spawn they are very protective of the eggs and fry. They will guard the area next to the eggs, but when the fry become free swimming the fry disperse throughout the tank every fish will be looked at as a threat and will be attacked by the pair.>
Also, I'm thinking about moving my Pleco (approx. 9 inches?) to the tank as well. Would a Senegal
bichir fit in with them alright?
< The Pleco would be looked at as a threat if it wanders into the Oscars territory, same with the bichir.>
I would be feeding the tank Hikari cichlid staple and frozen thawed bloodworms daily, along with earthworms about twice a month. Excited about them, love the personality of cichlids. Thanks!
< Forget the bloodworms, stick with the pellets and use the earthworms as planned. .Look at getting the book, "Enjoying Cichlids" by Ad Konings for some insights on mixing cichlids.-Chuck>

Scales are missing on Red Tiger Oscars 2/1/2010
<Hello Denise,>
My son and daughter each have a small Red Tiger Oscar.
<Bad choices as pets for children. These are very difficult fish to keep properly.>
The Oscars are kept in separate 5 gallon tanks with filters.
<Insane. Make that 55 gallons for each tank, and we're talking.
Five gallons is barely enough for a Betta, let alone an Oscar. Did you tell the pet store you were doing this? If they told you that was fine, then they're idiots. If it was your idea, and somehow you though they'd be fine for a while, then, well...>
They are fed 2 small gold fish feeders every other day and flakes on the other days.
<Did you read ANYTHING about Oscars before purchase? If you did, you'd known feeder Goldfish are a VERY BAD food item for Oscars. Not only are they a major source of parasites, they're also loaded with fat and thiaminase.
We have done the water changes and de-chlorinated the water. Lately we have been noticing that each of the Oscars seem to have white spots, but more like the scales are missing, not like Ick. I thought they may be scraping themselves on the gravel but we never see them do that and it is getting worse. Any ideas?
<Yes. You're killing these fish. Whether deliberately or through sheer ignorance, you've stuck two perfectly nice animals in enclosures they cannot possibly be maintained in, and then fed them the worst possible diet. So these lovely, intelligent animals are being poisoned to death.>
Denise F
<Denise, I really, really do not like yelling at people. And when people write back that their feelings are hurt because I've yelled at them, that's sad. I volunteer here precisely because I like fish and I like people. But
when I get messages like this, it's hard for me to return a measured, let alone kind, response. Not one aquarium book ever written would ever suggest keeping Oscars this way, so my only conclusion has to be you read nothing
at all before buying these animals. Given you haven't said anything about water quality, I have to assume you didn't cycle the tank for 6 weeks before adding the fish. So essentially everything that you could do wrong, you have done wrong. It's not the fish's fault, it's not the retailer's fault, and it's certainly not my fault; it's your fault. Time to read what I've sent you to, think about what you've done, and react accordingly.
These fish aren't going to survive these tanks, let alone get better.
Either return them or euthanise them.
If you want to keep them, you're going to need a 55 gallon tank for each one, or a 75-100 gallon tank for the two of them. Don't delude yourself into getting a 20 gallon tank now, and then saying you're going to upgrade in a couple months. These fish grow EXTREMELY fast when kept properly, and will need that 55 gallon tank within 6-9 months of hatching. So get real, focus on what needs to be done, and move on. Feel free to write back and
yell at me for being rude if that makes you feed better. But my concern here is for your fish, and the bad example it's setting your kids. Cheers, Neale.>

Re: scales are missing on Red Tiger Oscars, hlth., nutr. �� 02/02/10
Hello Neale:
<Hello Denise,>
My apologies for my ignorance. I did tell the pet store exactly my plans and purchased the Oscars at the same place. The same place I buy the feeders. Obviously they were either only concerned with the sale or they had less knowledge than I did.
<Well, you do have to treat advice from store clerks with caution. Some specialist retailers are staffed by outstanding fishkeepers, and I've learned a lot by listening to them. But all too often the generic pet stores employ staff who know little to nothing about fish. In general, take the advice, but double check against a book or a web site you can really trust.>
Many years ago, I too had an Oscar for many years, fed him feeder fish and never had a problem.
<It's like the old maxim, "playing Russian Roulette once and surviving doesn't make it safe". Work on predatory fish has demonstrated without any ambiguity that diets high in thiaminase lead to ill health and premature mortality. Do read Marco Lichtenberger's piece here at WWM on this topic.
The incidence of parasite infections following the use of cheaply produced feeder fish is very high. Furthermore, goldfish and minnows are rich in both fat and thiaminase, and Bob Fenner believes, after autopsies of numerous fish, that these feeder fish are the #1 cause of premature death of Lionfish. The #1 cause! These feeders are killing more Lionfish than bad water quality! Thankfully, feeder fish simply aren't sold in the UK, so this isn't an issue here. The hobby has moved on, and aquarists switched to safer, cheaper, and less expensive foods. But for whatever reason, the US market has changed yet.>
Never did the pet store say anything about having a 55 gallon tank, nor did they tell me about feeder fish being bad for them to eat.
<Not impressed by them, I have to say.>
Once we started noticing the problem. We immediately began the water changes every 3 days between 25 - 30%. We are now feeding them frozen, thawed shrimp and peas.
<Again, do go back and read about thiaminase. Shrimp contains a lot of thiaminase, and over time, over-use will lead to vitamin B1 deficiency. I'm sure you already know about how the Royal Navy was plagued with the problem
of scurvy back in the 18th century. The sailors were getting lots of calories, but for some reason would get sick within a few months of leaving harbour. The problem was that their diet, while adequate in other ways, lacked vitamin C. Over time this meant they became sick. Only with the introduction of citrus fruits into the sailors' rations did things improve (from whence comes the nickname for the British around the former Empire, "Limeys"). It's precisely the same thing here: shrimp, mussels, clams, squid and other thiaminase-rich fish and seafood may contain lots of calories and protein, but they also contain thiaminase, and over time, you're creating problems by using them. Restrict thiaminase-rich foods to once or twice per week. The rest of the week should be made up of foods
that lack thiaminase. These include good quality pellets (e.g., Hikari Cichlid Gold), earthworms, snails, fresh or frozen cockles, fresh or frozen tilapia fillet, and of course plant foods like cooked peas. Indeed, a perfectly adequate diet could be based around just good quality pellets plus the cooked peas to ensure adequate fibre.>
I have done a lot of reading over the past few days and the Oscars seem to be improving dramatically.
In addition we are currently looking into a 55 gal tank.
<That's fine for one Oscar; two will eventually fight in that space, unless by some miracle you have two females, or else a pair that get along from the word go.>
I thank you and appreciate your advice no matter how loud you were yelling.
<Glad to have helped. Good luck. Cheers, Neale.>

Oscars fighting �� 01/03/10
Hello WWM,
<Hello Phil,>
I have kind of a two part problem here and am finding it difficult to find any search results (WWM or www) that are what I'm looking for.
My situation is that I have a 55gal tank and would ultimately like to cohabitate 2 Tiger Oscars in it.
<Not likely to happen. A mated pair -- and I stress, already mated, not some random male/female grouping -- may well use a tank this size without problems, but Astronotus spp. are territorial and outside of mating prefer to exclude adults from their patch. On top of that, 55 gallons is barely, and I mean barely, adequate for a single adult Astronotus, let alone two.
Nitrate is a real killer, and once these fish top 20 cm/8 inches they are nitrate generating machines. End result is you need lots and lots of water to dilute the nitrate that accumulates between water changes.>
I am aware that a 75 gal is preferred for 2 Oscars due to the large bio-load of the species but I have a filter that turns over the water about 7 times an hour and I perform 2-3 25%-33% water changes a week all the while keeping an eye on the ammonia and nitrite/nitrate levels in the tank.
<I hear what you're saying, but I just don't see this working long term. 55 US gallons is less than 210 litres or 46 Imperial gallons, and by any standards that isn't a lot of water. A tank this size would be adequate for cichlids around the 15 cm/6 inch mark, but Oscars are more than twice that length (and therefore eight times the mass) and really need big aquaria.
Chronic nitrate levels above 20 mg/l can be lethal to Astronotus, and indeed Cichlidae generally, making them especially prone to Hexamita infections. Do understand that while a big filter can deal with ammonia and nitrite, it won't do anything about nitrate. That's all about [a] water changes; [b] controlling the food that goes into the tank; [c] removing uneaten food; and [d] using water volume to dilute nitrate between water changes.>
I added both of the Oscars within a week of each other, made sure they were both juveniles (about 3-4" a piece) and when I introduced the second I made sure to completely rearrange the tank setup so that no current territory was established.
<At this size are only mildly territorial. Likely not even sexually mature.>
Nonetheless they immediately begin to "dance" with each other and gradually became more and more nippy and violent which I had assumed was them working out the dominance and territory of the tank.
It's been 7 days now and they are still going at it sporadically usually ending with the slightly larger of the two establishing more of a foothold.
<Will likely get worse with time. With cichlids, there's plenty of experience to suggest that the bigger fish eats more food and therefore grows faster, and by stressing the weaker fish, keeps the weaker fish smaller and less of a threat. In the worst case scenario, the weaker fish eventually either starves, is physically bullied to death, or because it is stressed, succumbs to a secondary infection of some sort.>
In all of my Internet searching all I can find is either people who say "don't have more than one Oscar" or "my two Oscars get along fantastically."
<Indeed. The problem is Astronotus cannot be sexed. If you get two females, the minimal belligerence between them will be easily managed by providing enough space. If you get a male and a female, and they pair off, again, you should be okay given space and a certain amount of wrestling. But get a male and female who don't get on, and the male will stress/bully the female (he's actually only trying to drive her away from his territory so he can make space for a fertile female). If you get two males, then all Hell can break loose. Frankly, since you only have a 25% chance of getting two females, assuming males and females are equally distributed in the stock sold in pet stores, that's about the odds of any two random Astronotus "working out" with minimal fuss.>
I can't find anywhere how long might it take for them to establish dominance and get along or if it should be an immediate thing.
<It isn't something that happens once and for all. Astronotus aren't monogamous for life, so even if you have a pair, there's a constant process of bond forming as the two fish fall in and out of love (for want of a better term). On top of that, belligerence increases as fish become sexually mature, so while two fish might get alone one day, a month later they may well be much less tolerant. In theory at least, Astronotus are sexually mature at about 1 year old, at which point they should be about 20 cm/8 inches long. As noted already, sexual dimorphism is practically non-existent, save for the appearance of the genital papillae within a day of actual spawning.>
Should I wait it out and see if they are still just butting heads or should it have already happened and they're never going to live together?
<Likely the latter, at least in a tank this small.>
My second problem is that the albino and smaller of the two (by about a half inch) came home from the LFS with a small cyst of some kind on its belly directly anterior to the anal fin. It looks like its filled with either a clear fluid or air. It doesn't look like a pro-lapsed anus but I'm not exactly familiar with that so I could be wrong.
<Anal prolapses are quite common among Astronotus and indeed large cichlids generally. They are usually related to exposure to chronically poor water quality (especially with regard to nitrate). Metronidazole is the remedy, used as instructed on the packaging, but this absolutely must go along with optimal water quality. It's also important to check diet is appropriate. Feeder fish for example are bad, but earthworms are good, and things like unshelled shrimp and crayfish provide valuable fibre that help keep the digestive tract healthy. Some Astronotus enjoy cooked peas, and these are certainly worth offering on a regular basis. Wild Astronotus consume a range of things from snails and crayfish on the one hand to fruit on the other, and not just smaller fish. As is well known by now, feeder fish aren't safe, but you should still provide at least some fish, primarily thiaminase-free types such as wet-frozen lancefish or chunks of fresh tilapia fillet. Don't use fatty, thiaminase-rich fish (notably minnows and goldfish).>
The albino hasn't eaten anything directly but has been sort of filtering the sand and gravel. It spends most of its time laying still on the substrate though and might just not want to compete with the other fish for food I think.
<Indeed; see above.>
I did trying hand feeding but it just swam into the nearest plant and hid from me. I contemplated removing it into a hospital tank and treating for infection which would also allow for easier more direct feeding but I'm afraid it may disrupt whatever territory establishment progress that may have already been made with the other Oscar.
<Moving to a hospital tank is fine, provided the hospital tank is AT LEAST as good as the display tank in terms of water quality and oxygenation. No point at all moving a sick fish to a bad tank...>
I know that the easy option here would be to re-home the fish but if possible
I would really like to have an albino and a regular tiger Oscar together in my tank and would like to (within reason) try and make this work.
<Good luck on that... Seriously, it's really not a plan. For a tank this size, you'd have much more fun choosing cichlids that would thrive rather than struggle. For example, you could create quite a nice reef of Tufa rock and keep a colony of one of the Dwarf Mbuna species, maybe a couple of males and half a dozen females. You'd get to watch territorial behaviour rather than outright murder, and since you'd have a harem of females, the males would be busy all the time. Alternatively, a planted aquarium with a few pairs of something like Pelvicachromis taeniatus would offer a range of behaviours including pair forming, broodcare and so on. Watching cichlids exhibit the full range of behaviours, rather than just fight, is why aquarists keep them.>
Thank you in advance for your time.
<Cheers, Neale.>

Re: Please Advice, Arowana fdg., Oscar sys. �� 12/08/09
Dear Neale,
Good Morning.
<Hello again,>
Now my Arowana is eating the food that I provide except for shrimp food of Taiyo company. Some how it did not like this particular brand's food.
<Give it time. "Hunger makes the best sauce" is an expression we say in England; if you skip a meal or two, your Arowana will eat this food!>
Well. Goo news is that my 6ftX3ftX3ft is getting ready. I want to keep my silver aro along with 2 copper and 2 tiger Oscars in that. They are all together in the present small aquarium. I plan to shift them on 11th of this month.
Please advice me on the following things.
1. What type of stones/gravel should I fill in the bottom?
<Minimal. The Oscars dig, and the Arowana doesn't care. So use a thin layer (2 cm maybe) just to cover the glass and stop reflections. I'd go with smooth gravel of some sort.>
2. What type of filtration system is advised.
<Certainly some type of heavy duty canister filter will be required. Given how sensitive Arowanas are, and how messy Oscars are, don't take chances here! I'd go with at least two big canister filters, so if one breaks down
or needs servicing, the other will still be running. The Fluval FX5 (900 gallons/hour) is a good budget option for really big tanks, and has had quite good reviews. You might also consider using a small pond filter instead. Aim for at least 6, and ideally 8-10, times the volume of the tank in turnover per hour. Your tank is about 400 US gallons, so aim for 2,400 gallons/hour, minimum.>
3. How much lighting will be advised. Either in luminous or size of the tube light.
<Couldn't matter less. If you want some floating plants and Java ferns to decorate the tank, then you'll need at least 2 watts/gallon given the depth of this tank. If you don't plan on using live plants, then use whatever lights you think make the fish look pretty. Gro-lux tubes are nice.>
4. What kind of internal decorative advised?
<Minimal. The Arowana needs open swimming space. The Oscars will need a few caves; terracotta flower pots and similar such things work great.>
Thank you in advance.
<Cheers, Neale.>

3 year old tiger Oscar, hlth., env. -- 10/21/2009
Hi, my name is Shawna and I have a Tiger Oscar that is about 3 and a half years old now. I cleaned my tank about a month ago<"Cleaned?"... as in altogether? Better to not do this; but instead to change part of the water out, clean the sides down, vacuum the gravel at weekly intervals>
and now my Oscar has been getting strange marks on him.
<Likely from a loss of nitrification (biological filtration capacity)>
At first, along the top of his body just underneath the top fin on both sides, he was starting to look pale.
His stripes also started to become very pale and white in color, which is usually caused from stress i thought. This went on for a few days and then his eyes started to get very cloudy.
<Bad... burned>
This cleared up within a week and I started to think he was all better now. Then i noticed where he used to be pale in color on his body, by the top fin, he had a spot that had very minimal peeling and now his scales seemed to be a bit swelled. It has also seemed now that his tiger stripes have pretty much disappeared or faded out where this is happening.
He is still eating and is swimming normal, really he seems perfectly normal other than these swelled scales. The symptoms to me remind me of a human sunburn!
Instead of getting red, he gets pale, he is peeling and his scales are swelling much like how a sunburn bubbles. I had a Marine Glo light which glows a blue which has been used for some time now so i don't think its lighting. He is in a 108 gallon tank with a 6" goldfish, a 7" Dempsey, a 4" peacock cichlid, an 8" Pleco and a smaller other fish that I have no idea what it is that was given to me months ago. I have had my water tested
<What results? Appreciable ammonia et al?>
quite a few times and have not changed a thing that i have done since i have gotten him. The only thing that changes is the type of food. Right now I am feeding him floating cichlid pellets. On occasion, crickets and guppies but i have not done this for quite some time. I have never ever fed him low quality foods!! Im not understanding what is going on because he is not acting strange at all, I have noticed that a couple times when the paleness started, he seemed almost itchy but that has stopped. I hope nothing is serious and there is a solution. Thank You
<Mmm, again... the clean-out... Please read here:
and the linked files above; esp. on troubleshooting. I would be looking for a good starter medium, like Dr. Tim's "One and Only". Bob Fenner>

Astronotus (systems; behaviour; health) �� 04/22/09
My question is like many other ones, but also different in a few ways.
<Oh? Most Oscar questions boil down to too many specimens in too small an aquarium, with too little care being taken over water quality.>
I have a Orange Albino Oscar, and a Black Tiger Oscar, and for about 4-6 months they've been great together.
<Famous last words. Let's be crystal clear about something: Oscars aren't sociable fish. They are territorial, and except in big tanks, they often don't get along. Juveniles are gregarious to be sure, but as they age, they
become less accommodating. Mated pairs generally form loyal bonds and work well together, but territorial males will be hugely intolerant of one another, and will fight.>
Until recently, My Orange Oscar, looks kind of like it's shedding, on both of it's sides in the middle.
<Fish don't normally shed their scales. So if you have a fish obviously losing scales, that tends to mean either it's sick, or it's being physically damaged, e.g., through fighting.>
It lays on the bottom (not on it's side) either normal, or very slightly tilted. He's not to active, he comes to the top when i feed them, but won't eat much. The reason i said my question was different from the ones on your site at the moment, is because i have the tiger Oscar in there with it, and it seems like almost every time i feed them, the black Oscar will jump out of the water and land on the orange one.
<Sounds like aggression or bullying to me.>
The orange Oscar is also missing it's top fin since this morning. i don't see any pieces of it's fin in the tank, so I'm thinking it got eaten.
<Again, consistent with social behaviour issues.>
Last but not least, i have a odd tank I'm not to sure of the tank size, (30-50gal)
<Dismal. You need more than 50 gallons FOR JUST ONE OSCAR, let alone for three of them!>
i know that's a big difference but it's a half octagon tank, and i don't know how to measure it.
<Easy. Empty the tank. Fill the tank up again, counting how many buckets containing X gallons of water you need to fill it.>
I run two 20 gallon topside filters,. the kind that hang on the back.
<Hang-on-the-back filters are hopeless for large cichlids. You need big, heavy-duty filters with inlet and outlet pipes at different ends of the tank. External canister filters are the ideal, but wet/dry filters and
reverse-flow undergravel filters can work well too (though the latter will need a gravel tidy to keep the Oscar from upturning all the gravel). Allow 8 times the volume of the tank in turnover per hour; e.g., a 100 gallon tank would have a filter rated at 800 gallons per hour. Sounds a lot, but trust me, a 40 cm Oscar makes A LOT of mess.>
i have a air tube on the back of the glass letting air bubbles go into the water.
i feed them feeder minnows,
<Stop this! Feeder minnows are completely the wrong thing for these fish, and in the trade we call these "parasite bombs". Minnows, goldfish and other Cyprinidae contain thiaminase and fat, both of which cause serious health problems for Oscars. You certainly aren't doing your Oscars any favours here. See those strong jaws they have? They're for crushing shells. Oscars LOVE crayfish, shrimp, snails and other such things.>
and fish flakes, and algae pellets, which they seem to love oddly enough.
<They're omnivores, and plant foods (such as cooked peas) are a good addition to their diet.>
I do my 25% water change twice a month, and i notice that a lot of people say once a week?
<Yes, you should be doing AT LEAST 25% water changes per week. In an undersized, under-filtered tank like yours, twice a week would be better. Look up Hole-in-the-Head disease and Hexamita infections. These are difficult (and expensive) to treat, but plague Oscars kept in conditions such as yours.>
Please tell me if i should start doing the 25% change more often, such as once a week.
Please help, thanks, Mike F.
<Done my best. Do read some more, here:
Cheers, Neale.>

Questions regarding a new filter system. 3/31/09
Hello Crew,
I have a quick question again I want to make sure that my fish have the proper filtration needed to keep conditions good for them.
<Fire away.>
I have a 55 gallon tank with one tiger Oscar and one red Oscar.
<If these are both males, there will be a lot of fighting when they mature. I'd recommend one Oscar per 55 gallons, and would only ever keep two if I wanted to breed them (which I don't, since offloading the hundreds of fry is very difficult).>
Ammonia and nitrates are all at zero, and I do a weekly water change of about 20% to 25% and vacuum the gravel.
<Fine; do note Oscars are very intolerant of nitrate, and levels above 20 mg/l vastly increase the risk of Hexamita and Hole-in-the-Head.>
I have just purchased a new under gravel filter along with a power head that pumps around 400 gallons per hour.
<Not a good plan. Oscars like to dig, and in doing so, will short-circuit the flow of water through the UG filter. So while you might use the UG alongside other filters, you'd have to make sure that the other filters are 100% up to the job of maintaining these fish. Don't rely on the UG for anything. Since Oscars are big fish, you're after a turnover rate of 6 to 8 times the volume of the tank per hour. So a 55 gallon tank would require 630-440 gallons per hour. This is EXCLUSIVE of what the UG provides. The nightmare scenario otherwise is that you go away for a day, the Oscar uproots the undergravel, and because filtration rate then plummets, there's an ammonia spike during your absence. However, you could use a gravel tidy
to secure at least 2/3rds of the gravel bed in place, and that would be one way to prevent this problem; combined with a canister to form a reverse-flow Undergravel filter, and that would work very well.>
I also have a hang on the back filter that I have left there just to help a little, it has been there since I set up the tank I wanted to keep all the good bacteria that it had.
<HOB filters would not be my preference for these big, messy fish; they lack the oomph to keep detritus at the lower levels of the tank moving.>
This filter cycles around 200 gallons per hour. Between the two filters I am pretty sure that I have enough filtration to maintain the tank. I am aware that the Oscars will make bare spots by digging in the gravel, but mine do not dig too much so I am pretty sure that they should do fine.
<They aren't digging yet...>
They are a male and female and I want to keep them as happy and their water as clean a possible so that they may possibly mate.
<How have you sexed them? You can't sex immature Oscars, and even when mature, you can't sex them unless they are actually spawning, because you have to look at their spawning papillae to tell the males from the females. I'd also ask *why* you want to breed them; Oscars produce thousands of eggs, and realistically you'll end up with hundreds of fry. The market for these is very small, and since yours will be mixed rather than pure-bred fish, the market will be even smaller. Think EXTREMELY carefully about this.>
I am also looking into acquiring a larger tank I know that they are going to require more room when they mate, however I know that I still have time they are they are still only around 9 months old.
<They grow extremely rapidly, so start shopping now.>
I am very grateful for any more advice that you can give me they are my pride and joy and everyone loves to stare into the tank and watch their antics.
<Much written about them here at WWM; start here:
Do please pay attention to diet; the usual thing of throwing goldfish at them is about the worst thing you can do. Don't overfeed, don't use live fish, and concentrate on a balanced diet of healthy foods including greens.>
They love all the attention that they get as well, they are very brilliant and fun creatures to have in my home and I want to keep they healthy and happy.
<Yes, they are lovely fish. Make good pets.>
Thank You,
<Cheers, Neale.>

Re: Questions regarding a new filter system. 4/2/09
Neale, Thank you for the answer I had never thought about a gravel tidy but I am glad you mentioned it.
<Happy to have helped.>
I know that these guys grow very quickly, they have proven that, I got these guys when they were about one inch long. They are now around 10 inches each and are very spoiled.
<Oh dear!>
They also do have a varied diet, they get cichlid gold pellets, along with peas, freeze dried plankton and krill. They do not get goldfish but on occasion they do get rosy red feeder minnows, that I have quarantined at my home for about a month and treated to make sure that they have less of a chance of getting sick from them.
<Still, don't use Minnows. Parasites are one issue, but the other two are thiaminase and fat. Minnows, and indeed seemingly all Cyprinidae, contain a lot of fat. Accumulation of fat around the internal organs seems to be common among predatory fish that die prematurely. Perhaps the lack of exercise makes things worse for aquarium fish compared to wild fish?
Regardless, there's really no point taking this risk. Thiaminase is an enzyme that breaks down Vitamin B1. Until very recently aquarists didn't think about this issue at all, but recently people have become aware that at least some mystery deaths may be down to vitamin deficiency, caused by use of thiaminase-rich foods. Again, all Cyprinidae seem to contain this enzyme, including Minnows and Goldfish. So yet again, there's no point taking this risk either. Finally, I'd add a general observation made by many aquarists that predatory fish fed feeder fish are more aggressive than those that aren't. Unless you have an obligate piscivore, there are NO good reasons to use feeder fish, and MANY good reasons not to. I cannot stress this too strongly. You aren't doing your fish (or your pocket book) any favours.>
They only get around 10 of these about once a month.
<Still 10 too many... If you want to feed them live food, then think about what Oscars actually eat in the wild. See those huge, strong jaws? They're for crushing shells. In the wild that would include crayfish, snails and crabs. So find some live crayfish or snails of suitable size, or see what happens. Since these are the *natural* food for Oscars, the result will be a happier, healthier fish. Otherwise, earthworms are a real treat, and for most fish, these are Nature's perfect food. Full of decaying plant material as well as grit, they are a meaty, fibre-rich treat most fish just love. If you have a garden where pesticides aren't use, then you can collect your own for free! What could be better?>
I am currently shopping around for the larger tank however, and hope to find what I need at a good price.
Thanks again for the advice.
Thank You, Heidi
<My pleasure, Neale.>

Oscars V Mbuna Cichlids 4/1/09
I just converted my 100g saltwater tank to freshwater. Been running for a week now, cycling all over again (no patience) fishless and will remain so for about another 2-3 weeks.
Changed the lights to two t-12 fluorescent (not wanting any live plants).
<Depending on light intensity, algae can be a problem in cichlid tanks.
Under dim lighting, diatoms are usually the thing. If the water movement isn't strong, blue-green algae is common as well. Hair algae tends to crop up in tanks with high levels of nitrate/phosphate. Unfortunately, the pretty green algae that looks so nice on rocks (and is eaten by the Mbuna) requires very strong lighting. In other words, lighting may be more important than you think.>
Love Oscars but did not know if I had the space to keep two and if anything else would be able to go in this size tank with two Oscars.
<Best to keep Oscars singly, to be honest. Males are feisty, and because you can't sex Oscars unless they're spawning, getting two at random has a 25% chance of ending up with two males. If you get a boy and a girl, a 50% chance, then the problem is that they will spawn, and you're suddenly lumbered with hundreds of unwanted baby Oscars. Much better to get one Oscar, and then fill out the tank with some large dither fish (big barbs for example) plus a suitable Loricariid Catfish and perhaps a Bichir for the bottom, if you like oddballs.>
I am running the Fluval fx5 and will be getting a surface skimmer as well.
<Sounds good. With big tanks and big fish, I recommend 6 times the volume of the tank in turnover per hour, and ideally more. The Fluval FX-5 should be ideal. Do keep the receipt though, or buy from somewhere with a good returns policy (e.g., a local store rather than mail order) because while Fluval filters are generally good, and I've often used them, the odd lemon does seem to come off the production line.>
I have also been looking at the Mbuna Cichlids but not sure how many would work to stop aggression and how many I could get away with in this size tank ( I would want the most fish possible if i went this route).
<Some personal thoughts are here:
Follow the links to other articles and FAQs. I'd HIGHLY recommend spending some time tracking down any of the Konings or Loiselle books listed here:
You can pick some of these up secondhand for very little money. People make
huge mistakes with Mbuna all the time, and instead of the colourful "freshwater reef tank" they were expecting, they end up with a bunch of muddy-looking hybrids that batter the heck out of each other. Among other things, social behaviour and hybridisation should be considered. For beginners, there's a lot to be said for choosing the smaller ("dwarf") Mbuna alongside relatively peaceful species such as Yellow Labs. Whatever you do, don't scrimp on the rocks, since the more cover you have, the better the fish will behave. Overstocking is an option, but it has costs in terms of water quality, and like all cichlids, Mbuna (and Malawians generally) are sensitive to nitrate. The all-too-common approach of adding "one of everything" tends to result in [a] the dominant fish killing the weaker species; and [b] lots of hybridisation. Hybrids are a bane on the hobby, and have really helped ruin this particular niche. Spend money on quality fish. Choose fish from different genera to avoid hybridisation, i.e., only one species of Pseudotropheus (including what are sometimes called Maylandia and Metriaclima), one species of Melanochromis, one species of Aulonocara, etc. Decide if you want just random colour or interesting behaviours; if the latter, then creating a proper harem makes sense, with one male and multiple (not just one!) female. Quite possibly,
concentrating on a single species would work well, as here with Placidochromis:
You could mix these with Labidochromis and Aulonocara quite easily, resulting in a mix of blue, yellow, and red fish without any risk of
(serious) aggression or hybridisation.>
The ups and downs of the two choices would be appreciated and any information you could give me on doing a 100g Mbuna Cichlid tank would be greatly appreciated as well.
<Cheers, Neale.>

Re: Oscars V Mbuna Cichlids 3/31/2009
Only reason I was asking about the pair in this size tank was because the LFS has a spawning pair they received from someone.
<Ah, someone got fed up with dealing with the fry...>
They are both about 9 inches long.
<Still on the small size.>
I like the idea of doing an single Oscar with some dither fish.
I also do like the Bichir. So my next question (I just want to make sure I am being fair to the fish) would be if one Oscar, a Bichir, and maybe 3-4 Panda, Tinfoil, Redfin African, or Rosy barbs, and maybe some sort of Loricariid Catfish.
<Tinfoils are the classic choice. I fear African Redfin Tetras would be eaten. Rosy Barbs and Panda Barbs (Puntius fasciatus) would be somewhere in the middle there, depending on the relative size of the barbs and the Oscars. I'd probably not risk it except will full-grown Barbs. For that matter, Rosy Barbs can sometimes be nippy, and do certainly require cooler water than Oscars. So, instead, look at Puntius filamentosus, Puntius mahecola, Puntius lateristriga, Hypsibarbus wetmorei, Hypselobarbus jerdoni. The larger Luciosoma should work too. Really, anything 2/3rds or more the size of the Oscars upwards should be safe.>
Would this be too much for a 100g system.
<One Oscar, one 30 cm/12 inch Plec, one 30 cm/12 inch, Bichir, and a school of largish barbs should be just fine in a 100 gallon system.>
Thank you again for your timely feedback and keep up the great site.
<Happy to help, Neale.>

New Oscar Fish (Astronotus ocellatus in a 2 gallon tank) 3/12/2009
I bought an Albino Oscar for my husband yesterday, even though we did not have a tank set up yet, because he had wanted one, and I saw this beautiful fish and had to buy it. We put him in a 2 gallon tank, until we can get
our 55 gallon up and running, which will probably be this weekend. Is Oscar in a trouble, or will he be okay until then? He is only about 3 1/2 in. right now. I have no Oscar experience and would like to know what we need to do with our 55 gallon as well to make it a healthy place for our fish. the water is a little cloudy today, but he swims around a lot, and likes to chill at the bottom sometimes behind a little tree. I want him to live a long time, so any advice is appreciated.
<Greetings. Get the Oscar out of the 2 gallon tank, NOW. He is not "chilling" he's showing signs of stress. Fish aren't people, and they don't chill, keep it real or hang loose. They're fish. In the case of Oscars, that means swimming about in midwater. Cloudy water implies, at best, dirty water, and at worst an incipient oxygen crisis mediated through a bacterial bloom in the water. Either way, my crystal ball sees a sick fish in your future. A 2-gallon tank is not a fish tank; it's a bucket. A 3.5 inch Oscar needs at minimum something like 40 gallons to even begin to have much chance of survival. A 55 gallon tank is just about tolerable, and we're talking zero margin for error here, acceptable for a small adult Oscar. Most Oscar keepers would recommend a tank 75-100 gallons in size as being closer to what's required to actually enjoy a healthy fish with the minimum of stress to you and the fish. It also needs a filter rated at 8-10 times the volume of the tank in turnover per hour; i.e, your 55 gallon tank will need a filter rated at 440-550 gallons per hour. Anything less and you'll have muck on the substrate and ammonia in the water. Eventually, you'll be dealing with a sick fish. I cannot stress too strongly how demanding Oscars are, and short of buying a Great White Shark, it's hard to imagine a worse impulse purchase. Everything you need to know about Oscars is here:
Read, digest, and if you have problems, please do get in touch.
Cheers, Neale.>

Question in regards to Fish sold at Retail Stores (RMF, do you have thoughts?) <None different, beyond. RMF> �� 03/02/09 Hello. I have an inquiry in regards to fish sold at retail stores. I was in a Meijer yesterday and I was looking at their fish and I notice that they were selling Albino Oscars. There were three of them in a tank that in my opinion was a little over crowded. No these Oscars are obviously on the young side as they were only between 2 1/2 to 3 inches in length. My question is has to do with how the stores handle fish like these. I know Oscars grow very quickly and if they have been at he store for a while, how much does that play into their health? I am not looking to buy any of these guys as my experience and knowledge of keeping fish like these are severely lacking. However, I do enjoy reading information on your website and I find Oscar fish some of the most intriguing breeds I have seen. If memory serves right, I remember reading on your site that if an Oscar is kept in a confined safe, that its growth will be stunted but its internal organs keep growing. This can be fatal to an Oscar's health. Thank you for your time and the great service you provide for those that keep fish as pets. Best Regards! Neal <Hello Neal. Broadly speaking, we'd always prefer people bought their fish from bona fide aquarium shops rather than generic pet stores or department stores. The reality is that the wider the range of products a store handles, the less deep its experience and information per product is likely to be. Aquarium shops tend to employ people who keep fish, and often the managers at least will be competent aquarists at some level, perhaps being quite expert in some particular niche of the hobby. Department stores will be tending to employ people looking for a career in retail, and while they may be hobbyists as well, it's equally likely they only know whatever their training manual or supervisor has told them. Another difference will be in the range of hardware offered. A department store may well stock potentially huge cichlids or catfish, but the tanks it sells will usually be (cheap) 5-, 10-, and 20-gallon tanks that appeal to the low end of the market. Dedicated aquarium shops will sell much larger aquaria, since they'll be attracting hobbyists at all ends of the market, including marine fishkeepers and aquarists keeping demanding freshwater fish like Rift Valley cichlids. The garden centre five minutes walk from my home is a case in point; the biggest tanks it sells measure about 15 gallons, but they regularly get in stock things like Common Plecs and Black Sharks, both of which couldn't even be physically wedged into a 15 gallon-tank when mature, let alone kept in one! Now, as for stunting. There is very little evidence that this happens for most fish, and certainly not in the "internal organs keep growing" way sometimes suggested by ill-informed aquarists. Fish stunting is known from certainly schooling food fish, notably Carp and Salmon. On the other hand, it isn't an issue with other food fish, things like Tilapia and Catfish, which pretty much get to as big as their food supply allows. A few years back a TFH editor reared a tank of Oscars in conditions that would be thought to stunt them. He found that provided he maintained water quality, e.g., by 95% daily water changes, even in a 20 gallon tank (if I recall) the Oscars got to full size. Lots of Oscars don't get to full size, yes. They either [a] die; or [b] have small fish genes; or [c] didn't receive enough food, particularly through the critical first few months of life. But even a "small" healthy Oscar is going to be 8-10 inches in length, and most get much bigger. I'd recommend reading up on these fish before doing anything else. While fascinating in many ways, they're extremely demanding in others, and in poor conditions are very prone to diseases, particularly Hexamita. There are cichlids for every budget and interest, so an evening spent reading through one of the many excellent cichlids books would be time well spent. Do see here: http://www.wetwebmedia.com/FWSubWebIndex/bookswwmsugg.htm Hope this helps, Neale [sic].>

Three Oscars in a 55 Gallon Tank 2/25/09 Hello, I have been reading over your website, and many, many others. I have recently purchased a 55 US gal aquarium. I initially set it up with the standard filter system that it came with. The aquarium is a TopFin brand. I set it up and let it stand with filter running for the cycle period, approx 2 weeks. I did my water tests with API drops for those two weeks, and all looked good. I then went and purchased 3 gouramis.. I kept an eye on it, and got the expected ammonia spike, which rectified itself with in three days. The fish were all healthy, then I made the error of buying two spotted catfish from our local Wal-Mart. With in three days I had parasites and ich. I did all I could with medication for ich and parasites, 25% water changes weekly and feed every other day and removed the carbon element in the filter. Kept the temp at 75-76 degrees. I was unsuccessful, as the fish did die. I then sterilized the tank and decorations according to one website, and let the tank re-cycle for two weeks. Now I have three Oscars. I purchased one, and the other two were given to me, or faced being flushed by their previous owner. My question I have is this. Can I support three Oscars in a 55 gal tank? <Eventually the Oscars will grow and only one will be able to live in a 55 gallon aquarium.> Since I got the additional two Oscar, I have added a aqua cycle 70 filter, the type that has the sponge, then the carbon and then a bio pellet bag. I have been over dozens of website and talked to three of my local pet supply stores. No one can give me the same answer twice! I really don't have the room or money to purchase another tank, nor do I want to get rid of my Oscars. (by the way one is a red Oscar, Midnight, one an albino Oscar, Chalky, and one is a tiger Oscar, Duke.) I make sure I test the water weekly, and do a 25% water change weekly, and along with the water changes add aquarium salt per instructed dosage. So far they are good, the water test are showing that ammonia is 0ppm, nitrites are 20ppm and the nitrates are 15ppm, both of the nitrates and nitrites are slowly going down, and I keep the temp at 80 degrees F. ( I have had them for about two weeks now) The three Oscars are currently juveniles, no longer than 1" to 2" long. They are currently healthy and active, especially when feeding. I use a brand of Cichlid pellets, supplemented with freeze dried brine shrimp, and I make sure that they all get plenty of food. I have not seen them fighting, other than the occasional mouth biting, and they seem to be doing good. At night they all clump together behind a tall fake plant. I do need to get more cover if I can keep them, which I plan on doing after I read your response! I have read many horror stories of having too many Oscars and they get unhealthy and die. I have also read many stories of three or more Oscars living happily for many years in a 55 gal tank. I need some type of definitive answer as to whether or not I am setting myself up for heartbreak and disaster down the road, and dooming my Oscars to a slow and painful death because the tank is too small. Please let me know your thoughts, as I am very interested in your opinion. Your site seems to be very professional, and up-to-date. Thanks in advance Joe Leimbach < To keep your Oscars healthy you need to keep the nitrates under 20 ppm. The ammonia and nitrites need to be zero. Check the nitrates of your tap water. As your Oscars grow the nitrates will continue to rise. When they get to the point to where the nitrate levels go higher than 20 ppm between water changes then you start to have problems with Hole-In-The-Head and bloat. You then need to do larger water changes or more frequent water changes. Sometimes even both are needed. If you don't have the time nor the effort to do this then you need to reduce the bioload of the tank by reducing the number of fish. In areas with lots of agriculture the nitrates may be up to 50 ppm right out of the tap. This makes it very difficult to keep fish.-Chuck>

Oscar Tank Problems 2/11/09 Hello there- my name is Sieba, I live in central California in the mountains. I moved in with my boyfriend 2 years ago, and have since been the one taking care of the fish tanks. The tank is about 150 gallons, two Oscars, one a foot long, the other about 9 inches. Two plecostomus each 14 inches long, two jack Dempseys, each about 7 inches long, and one foot long catfish. is this tank overcrowded? < Check the nitrates with a test kit. They should be around or under 20 ppm. If they are higher than this they need to be reduced with water changes. If you cannot keep it under that level with weekly water changes then you should reduce the number of fish so that water changes will keep the water under these levels.> How much filtration should I have? < The filters should turn the entire tank volume over 3 to 5 times per hour. This means that your filters should pump at least 450 gallons per hour.> What temp is best? < Somewhere between 75 and 82 F.> I really want to take care of them properly since my boyfriend doesn't do a thing to help. The Oscars have these white pock marks on them, I treated them a few weeks ago with fungus clear, but have no idea if that was the correct treatment to use. The fish store people here know NOTHING!. Please help me! Thanks! < The white marks on the fish are commonly referred to as Hole -In-The-Head Disease. It is usually associated with poor water quality and diet. I would recommend doing a 50% water change, cleaning the filters and vacuuming the gravel. Look to change the diet to a quality pellet food like Spectrum New Life. If the holes get worse you might try treating the tank with Metronidazole. If you are close to Sacramento then there are members of the Sacramento Aquarium Society that may direct you to stores that may be better informed.-Chuck>

Astronotus (tank size) 1/15/09 Hi, can I keep an Oscar in a 40 gallon tank? thanks <Short answer: no. Oscars are too big and too sensitive to poor water quality to be maintained in tanks this size. You'll need 50% more capacity to keep a single specimen easily. Cheers, Neale.>

Re: Astronotus (tank size) 1/16/2009 Thanks Neale for the quick reply. Is it possible to keep it in a 45 gallon tank with only one Oscar by itself? I will do weekly water changes to maintain the tank. Thanks again. <No. These are big fish, easily 30 cm/12 inches and a mass of up to 750 g (about a pound and a half). That means they produce a lot of waste, and even with a big filter, you still have the problem of nitrate. Nitrate is at least once cause of Hole-in-the-Head, a very common cause of Oscar mortality. Sure, you could do 50% water changes every other day, but this is a cichlid that lives for 10+ years and changing that much water gets tedious pretty quickly. There's absolutely no point to keeping them in a tank under 210 litres/55 gallons, and sensible aquarists only keep them in substantially bigger tanks. If you have a 45 gallon tank, there are plenty of cichlids in the 4-6 inch range that would be a lot of fun to keep. Have a look at Rainbow Cichlids, Salvini Cichlids, and Honduras Red Point Convicts, for example. Electric Blue Dempseys are all the rage here in England, and even though I'm not wild about these fancy-pants artificial forms, even I'll admit they're striking animals. Cheers, Neale.>

Size of tank / cloudy water, Oscar sys. 12/10/08 I don't remember the formula to find out the number of gallons. Length X width X height X WHAT? <Have no idea, I do all this stuff in metric. Much easier! 10 x 10 x 10 cm = 1 litre. But if you insist on Ye Olde Worlde measurements, then according to Google, one cubic foot is 7.48051948 US gallons.> I have 37 gal tank (I was told it was, I don't think it is), with a heater, filter,& a 6 inch Oscar. (Which has been running a month) <Too small for anything but a really young Oscar, and at 6 inches (15 cm) this Oscar is well beyond that point.> The Oscar is eats floating pellets twice daily. (None in tank when finished) <Pretty typical for Astronotus!> Water cloudy - partial water changed & filter changed. Still cloudy, what next? Thank you <Tank is overstocked; too much fish, too little water. Buying a bigger filter would be good money after bad. Astronotus need tanks from the 55 gallon mark upwards. They're big, messy fish prone to disease (e.g., Finrot, Hole-in-the-Head) when kept for long in sub-optimal conditions. Cheers, Neale.>

Re: Size of tank / cloudy water... Oscar sys. 12/10/08 Thank you. FYI; Height X Length X Width X 7.5 = gallons <I believe that's what I said, only more accurately. Height (in feet) by length (in feet) by width (in feet) gives you cubic feet. There's 7.48051948 cubic feet to each US (as opposed to Imperial) gallon. As I'm sure your maths teacher reminded you many times, the units are critical! So don't forget about them. Do your sum in inches and you'd get a totally different number (say, 12 x 24 x 12 inches for a two foot tank) gets you 3456 cubic inches, when multiplied by 7.5 comes out as 25920 cubic inches, an answer that isn't in the least helpful! In any case, your tank is too small for Astronotus. Cheers, Neale.> Re: Size of tank / cloudy water Thank you. I was wrong, a pet shop owner gave me the wrong information. <Glad we could help! Enjoy your fish, Neale.>

One of two Oscar fish died: Should I get a new tank mate for the remaining Oscar? �� 10/02/08
Hello. I'd like to ask your advice on buying a new tankmate for our Oscar fish.
<Short answer is "No"...>
I recently adopted two little Oscars (about 2-3 inches each) from a friend.
They get along very well; always swimming in pairs and sleeping together in the same rock cave. One day, while I was at work, one of my Oscars (the larger of the two) somehow managed to wedge himself into a little opening in one of the decorations I had in the tank. When I came home, he was dead. We're not sure how this happened.
<Almost certainly didn't "wedge" himself into something, but drifted in there when moribund and didn't have the strength to get out. In any case, mystery fish deaths are almost always down to water quality, so do review this. Oscars are messy fish that depending strong filtration, and even a pair of juveniles would be unwisely kept in anything below 55 US gallons.>
So, we took little Token out and gave him a full burial (my son demanded it).
But now the other fish just sits in the corner and ignores everyone.
<Don't worry; these aren't social fish and don't need friends. Be very careful about how you perceive animal behaviour: they don't think the way we do, and you transfer human emotions onto animals at your peril. If the fish "looks" unhappy, review the things MUCH more likely to be at issue, for example tank size, water quality, or the use of hideously bright gravel bouncing light upwards at the fish.>
My son is very sad. He thinks the fish is depressed over the lost of its friend. (Is it?)
Personally, I don't think these little guys have evolved enough to feel things like joy and sadness; but you don't tell that to a kid, do you?
<Sure you do. Bony fish have been evolving plenty long enough to have all kinds of behaviours -- just not the same ones as us. Most animals I know find the idea they think like we do rather insulting, in fact. So yes, tell your kid that these are territorial fish that live alone most of the time, only pairing up with partners for breeding purposes, at which point they form very strong bonds and make excellent parents.>
Anyway, I want to get my son a new Oscar to put in the tank (minus the little decoration of death, of course), but I'd heard from many sources that Oscar fish mate for life.
<Not strictly true. But it is certainly true that you can't simply put two Oscars in a tank and expect them get along. For one thing, males and females are visually identical, so you can't sex them. Also, like most other animals, the females are extremely choosy about who they mate with, and consequently if the female rejects the male, he can become very aggressive and will attempt to push her out the territory. This obviously is not a good thing in the confines of a fish tank!>
While that notion was very sweet to us at first, it became an obstacle when one of the fish died. So what do you think? Should I get a new Oscar for the remaining fish? Will that help it cheer up?
<Unless you have a gigantic tank, I wouldn't bother. Much better to choose a non-Oscar tankmate like a catfish or a school of large barbs or something along those lines.>
Will my remaining Oscar be able to get along with the new one?
<Don't bank on it...>
I don't want to bring home a new fish and have them fight day and night.
What should I do? And thanks in advance for any advice you can give.
<Do read re: Astronotus. Much written about this species... few surprises to be had if you're properly informed. Cheers, Neale.>

Travelling with Oscar. -09/02/08 Hi there! <Ave,> My husband and I are moving about 2 1/2 hours away and we are travelling with a 7 inch tiger Oscar. I was wondering what the best way to take a fish of that size a distance that far was. <Don't feed him on the day of travel (you don't want him messing the water above the minimum). In a big container, as big as you can get, filled with water enough to cover him, the rest air, and then with a tight fitting lid. Place a towel or blanket around the container to keep it warm. Every 30-60 minutes, it wouldn't be bad idea to loosen the lid to refresh the air supply, but otherwise 2-3 hours should be fine. If you have a good relationship with your local retailer, you'll be able to get the large polystyrene boxes used to transport fish. These are (obviously) ideal. Otherwise 5+ gallon buckets, or even picnic coolers, will do great. There are battery powered air pumps available, and these can make all the difference when transporting big, sensitive fish long distances.> I had planned on just putting him in a bucket with a lid, but wouldn't he need a heater? <Assuming he doesn't get too cold for too long, he'll be fine. Water keeps its heat for a while, and the towel will insulate the bucket that bit longer.> Please respond soon, we are planning on moving in a couple of days so I need to know if I want to keep my darling Dave alive for the trip, (which I do, of course!). Thank you so much! Lena. <This article is focused on marines, but the basic facts hold true for freshwater: http://www.wetwebmedia.com/ca/volume_3/cav3i6/Moving.htm Fish travel quite well, otherwise the tropical fish industry would never have gotten off the ground! The main thing is to be methodical and do things one step at a time. Unless something goes catastrophically wrong, like you drop the fish onto the highway and it gets flattened under a Mack truck, there really isn't much to go wrong. Really, the tricky bit is moving fish tanks, because the silicone seals are easily twisted and damaged. The fish on the other hand are quite easy to move. Done it many, many times. Cheers, Neale.> Re: Travelling with Oscar. -09/02/08 Thank you so much! I'll let you know how he does after the move. Lena. <Cool. Have a safe trip! Neale.>

"Slash" our Oscar, concerns w/ "worms" in the tank 8/12/08 we got an Oscar about 4 months ago, and he has come around pretty quick! he is an amazing fish, as he is our first Oscar. he has had these little "worm" looking things on the inside of the tank, they are extremely small, and move around. they have not attached to him, and don't seem to be bugging him, but they are driving me absolutely crazy!! we feed him a high grade pellet food, and about 1-2 times a week he gets frozen treats like meal worms, or brine shrimp. he is in a 55gal tank, with a power filter for 50-60 gal (up grading to a canister filter), we also do about a 30 % water change weekly. I know its hard without seeing it, but what could these "worms" be? and how the heck to we get raid of them!? thanks for the help!! Desiree, Todd and "slash" <The "worms" are most likely Planarians, in other words flatworms. They feed on the food you've given the Oscar. As you know, Oscars are very messy fish. The fine particles they produce get everywhere, especially if the tank is inadequate and water changes are infrequent. In both regards, you're at fault here: cichlids need BIG filters, and you should be using a filter offering NOT LESS than 6 times the volume of the tank in turnover per hour. Forget about the rating on the box telling you X filter is for Y sized tank... these estimates are based on best-case situations where a tank contains few, small fish, Neons for example -- not Oscars! You also should be doing AT LEAST 50% water change per week, with the gravel cleaned on a regular basis. It's the stuff you're not removing that the Planarians are eating. While harmless in themselves, they're a "wake up call" telling you of an underlying problem. Long term, excessive nitrate in the water will lead to issues such as Hole in the Head that are a real bother to treat. So please, upgrade your tank (too small for adult Oscars), upgrade your filter, and step up the water changes. Do this and the Planarians should fade away in time. Do see here: http://www.wetwebmedia.com/FWSubWebindex/oscars.htm Cheers, Neale.>

Oscar Gill Sticking Out 8/11/08Hi we have an Oscar fish for almost a year and we just changed him to a new 55 gallon tank. My question and concern is that if looking at him his left gill seems to be coming out further than his right when breathing. He also seems to be opening his mouth more when he takes a breath. I'm not sure why one gill is pushed out further than the other, our other fish/ Oscars are fine. Please help!!! Thank you. < I think what you mean is that the one gill cover doesn't completely close and maybe stays out a little more than the other one. There could be a growth or something within the gill that is preventing it from closing the whole way. I would remove the fish and restrain him with a wet towel from the aquarium and hold him down and gently pry back the suspect gill cover and look quickly with a flashlight to see if anything was in the way. Without actually seeing anything then I might suspect gill flukes and treat with Fluke-Tabs. Flukes could have come in with feeder fish.-Chuck>

Re: Oscar fish Oscar With Stuck Gill II 8/11/08 Thank you so much for your reply. The Oscar fish seems to be healthy except for the fact that his left gill doesn't open at all. The weird thing is that both gills work fine while he eats. He seems to be eating as much as usual, but his breathing is a bit irregular and a bit faster than usual. Do you think that taking Oscar out of the tank and putting him on a towel to inspect his non-working gill won't traumatizing him in some way? < It is going to be your call. You are correct that this will stress you Oscar in some way, but not moving water through this gill is like you trying to breath with one lung. The only way to find out what is going on is to inspect the area. If he gets worse then it will become more stressful later on.> We have already lost three of our oldest fish (when we did the switch to the new 55 gal tank) and we would really hate to do anything that might put his life in any kind of danger. The water is in optimal condition, their diet doesn't include any live fish, and the temp is an even 78Ã'°. We do a tank clean-up once a month which includes a filter and a 5 gal water change (we only use drinking water since our tap water is way to hard). Please advise, thanks again for all your help! Santi & Sky < Hard to believe that with a 5 gallon water change you don't have higher nitrates. Another potential problem may be some ammonia burn when the new tank was changes over. This is caused by an ammonia spike and it actually eats away or burns some of the gill filaments. These may heal over time.-Chuck>

Re: Oscar fish Changing Water In An Oscar Tank 8/13/08 Are you saying that is NOT good to change 5 gals out of 55 gals every month while cleaning the bottom gravel? Even though it's drinking water? Are you saying that it has to be a bigger qty. of water that needs to be changed? Could you please explain that to us, we keep getting different stories from different people :(Thanks again! < Oscars are big messy eaters. You are probably changing less than 10% of the water. It is hard to believe that your nitrates are not a problem. Usually I recommend at least a 25% weekly water change for such large fish, but you say the water chemistry is fine. As long as the fish are doing ok then that is all that really matters.-Chuck>

Tank big enough? 05/31/08
Hi crew! I have a 110 gallon Juwel rio tank, I already have a very small tiger Oscar in there, and I was reading through your posts and I noticed that it's possible to keep a few Oscars together in a 100 gallon tank? I wanted to get another one - the Oscar I have in currently around 10 cm in length from head to tail. He is the only fish in the tank. Thanks! <In theory you could easily keep more than a single Oscar in there. But here's your problem -- there's no reason to assume the established fish will accept another Oscar into its territory. At least not without a fight! Usually when people keep multiple Oscars they introduce them as juveniles, and then as the fish mature they remove surplus individuals so that they end up with a single compatible pair. Because Oscars are virtually impossible to sex externally (it's only reliably done when they're spawning by examining the genital papillae) you can't assume yours is a female and add a male, or vice versa. At 10 cm yours is likely close to being sexually mature, so adding additional Oscars of similar size would be very dicey. While you might get lucky, you might just as easily end up with a bunch of battered fish. So in reality, I think the safest approach is to leave the idea of a pair of Oscars alone, and instead add dissimilar fish that won't be eaten by the Oscar but are themselves mild enough not to cause territorial disputes of their own. Plecs, large Spiny Eels, Silver Dollars, large barbs and characins, large Climbing Perch and so on would all fit the bill. Cheers, Neale.> Gravel for Tiger Oscar 5/17/08 Hi, <Hello> I recently had a tiger Oscar who I believe died because he swallowed a stone gravel that got lodged inside him and the reason I believe this is because when he ate food he would pick up the stones in his mouth by mistake. Two days before he died I noticed him doing that but I didn't see if he spitted it out or not and when I came from work he was vertically facing down in the tank for hours until he died and there was a huge lump in his belly where his feces comes out; to me it looked like one of the stones. So I want to know what is the best gravel to use for tiger Oscars, should I use sand instead of large stones and how much do I need for a 55 gal tank? <Mmm, I like larger size gravel (like "pea", nominal 3/16" diameter) natural gravel for most larger species of Neotropical Cichlid tanks. Bob Fenner> Oscars and plants Oscars Redecorating The Tank 3/30/08 Dear Crew, As much as I like my Oscars, they are driving me insane. They are about eight months old and seems to hate everything in their tank. They are spitting gravel everywhere, pulling on tubing and attacking tank decorations. But this is not so much my problem. One of them is absolutely shredding any sort of plastic plants I put in there (She also tries to bite my hands when I clean the tank, but this is beside the point). She rips the plants apart and they get stuck in the filter. I want to have plants in my tank, it looks incredibly bare as is right now and it's really bothering me. Is there any sort of live plant, silk or plastic plant that can stand this kind of abuse? Do you have any recommendations? I realize that Oscars are notorious for this behavior, but I don't want my tank to look like a prison cell. <Your Oscars are cichlids that are very territorial. This includes moving things around to set up borders to their turf. This is pretty normal with large cichlids. Unfortunately live plants don't stand a chance and artificial plants won't be much better. Maybe large pieces of driftwood that has already been soaked to remove tannins can give your tank a different look.-Chuck.>

Oscar Tank With Dirty Water 12/29/07 I have a few questions. I have one Oscar (the black and red kind) and also two tinfoil barbs. I have had them for about six months. They are all housed in a 100 gallon tank. I do about a 30% water change every Monday. My fish absolutely love when I change the water is really fun to watch them swim under the water that is being poured. Anyway, I am having troubles keeping my water clear and my glass free from yuck. I have been putting AquaSafe water conditioner with BioExtract about every other week. I don't want to put to many chemicals in my water, that is why I do not do it every time I change waters. What can I do to help clear the water and the glass? I do make sure that the fish are eating all of their food in two minutes. All other food I take out, so it doesn't dissolve in my water. What do I do? Thanks for any help that you can offer. < Filtration is very important. You did not mention any details about the filters that you are using. Generally you need a filter that will move about 300+GPH. I prefer big outside power filters like the Emp. 400. It is somewhat noisy but does an excellent job and is easy to maintain. If space behind the tank is an issue then look at some canister filters. They work but I have found them a hassle to maintain.-Chuck>

Tank height/width for Oscar (Neale?) �� 9/27/07 Dear Crew, <Mitzi,> (Neale's my new hero with all his clear concise advice so if he's in, feel free to pass this onto him. Not that he wants more mail!) <No comment!> I'm pulling my hair out trying to decide which exact size bigger tank to get for my Oscar. He's only 4" and in a 90 gal now, I have time and I know I don't "have" to get a bigger tank, but I want it for him. <A great attitude.> No tankmates, just him. <Not even a Plec of some kind? My thinking is companion fish give the Oscar something to do while you're out. They provide some exercise too, as the fishes have to swim about to get out of each other's way. To be sure, Oscars are the Siamese cats of the cichlid world, very much human-centric animals that love the company of a trusted owner. But a Plec would do no harm and would double up as a useful cleaner-upper for removing little bits of food the Oscar leaves in the tank.> I do know I want at least 125 gallons and 72" long. <Very good.> But there's big price differences between 18" wide and 24" wide. <Indeed; to do with the thickness of the glass I think.> I also was under the impression I should get one at least twice as tall as a full grown Oscar-which would be 24" tall, is that true? <On the whole Oscars don't care. Depth is always a good thing, but volume is most important of all.> Or would 17" tall be tall enough? <Depends on the size of the Oscar really. A lot of specimens are kept in tanks that depth. But it's a little shallower than I'd recommend, if only because a full grown Oscar is quite deep bodied, and by the time you've added gravel to the bottom of the tank, it might look a little cramped. The fish won't care, but how things look matters too.> My LFS has a special on 135 gal tanks. They're 72" X 18" X 24" tall for $350.00 total. For about the same price I could get a 127 gal 72" x 24" x 17" tall tank. I wanted him to have 2 ft of room to turn around in. Which is more important? 24" to turn around in (vs. 18") or having 24" height vs. 17" ? 18" doesn't seem like much room for a 12" fish to turn around in, at the same time 17" doesn't seem like it would be tall enough for a 12" fish given their leaping abilities. <Tough call. My gut instinct would be to go with wider, shallower tank. Fish tend to be more stressed by feeling that they are "funneled in" to the left and right than how deep the water is below them. On the other hand, a shorter but deeper AND wider tank, say 60" by 24" by 24", would (in my opinion) be better than either. And likely cost the same.> Both are great prices (I think), I'm just not sure how important each is. <Six of one, half a dozen of the other really. But my gut instinct is to go with width over depth. It probably doesn't matter greatly to something as flexible as an Oscar. Depth/width issues tend to be more problematic with species that are inflexible, such as needlefish and gar.> If both are pretty important PLEASE don't be afraid to say so. I'd much rather pass up this deal and hold off 2 months and save up another few hundred dollars, which is what I'm leaning towards. Because for $600.00 I can get a 180 gal 72" X 24" X 25" tall tank-depending on how important you think height and width are. <I can tell you this sort of aquarium is unbelievably nice. I looked after two, 200 gallon tanks about this size, and in terms of aquascaping and communities they're really flexible. One tank was filled with Central American cichlids and decorated with MASSIVE slabs of granite collected from the beach. To see something like a firemouth cichlid DWARFED by its environment really lends the aquarium a "slice of nature" feel. I've also seen these tanks planted with 'giant' plants like Vallisneria asiatica, and the results are amazing. On the other hand, for a single Oscar this is probably overkill. If you have $600 then go for it, but it isn't as if a smaller tank won't provide an equally nice place for your pet to live. Once you get about the 55 gallon size, your Oscar is basically a happy fish. These things have been tank-bred for generations and aren't nearly so bothered by aquarium conditions as wild fish.> (Water changes would also be bigger with a 180 gal but that doesn't matter a whole lot, we're on a well & I have a 300 gal plastic stock tank to age it). <Indeed. I find that actually getting my 'rear in gear' so that I do water changes at all is the biggest labour. Once you have the pipes and buckets laid out, looking after a 10 gallon tank or a 100 gallon tank isn't very different. And, on the plus side, bigger tanks go wrong less often, so the headache costs drop markedly.> I'd really like your opinion as I know you'll tell it like it is. The opinions of ALL of you are very important and I put considerable amount of stock in what you say. <Kind of you to tell us this. Thanks!> What do you think? Mitzi <Hope this is food for thought, anyway. Cheers, Neale>

Re: Tank height/width for Oscar (Neale?) �� 9/27/07 Dear Crew (Neale) Oh good, my email did get answered by you, Neale :-) You seem to have the knack of answering in easily understood terms yet you're very upfront and not afraid to criticize when needed. I'm afraid after the 10th email asking, "Why did all my 47 fish die in my 2 gal Betta tank?" I'd probably lose my cool. <This does indeed happen...> You're much more patient and non-condescending that I could be. ALL of you are and I don't bother looking fish information up anywhere else anymore. <Glad we can help.> Yes, a 50" X 24" X 24" *is about the same price as the 125 & 127 gal tanks. But my heart is set on at least 6' long, I love seeing Oscars coast along a decent stretch of area. <Very good.> I like the thought of the 180 gal (6' x 2' X 25"). You've given me an idea with aquascaping that hadn't occurred to me. I don't have the extra $300.00 just laying around but it's something I can save up in the next month or 2 and add to what I have and get that bigger tank. It's all a matter of priority and this just happens to be one of mine. <Indeed.> It's strange. I've had my other fish for years and just "really enjoyed them a lot". But this little Oscar opened up a whole new world, I love this fish. He gobbles zucchini I boil for him like it's the best bug he ever ate. <Yep, Oscars eat plant material in the wild. No-one believes me when I say this, but wild fish are distinctly omnivorous.> The rest of my family claim I can't cook to save my life, yet my loyal little fish loves my 'cooking'. He's happy to see all of us but I'm the one he wags his whole body for. <More than likely.> I never had that from a fish before & I love him for it, even if it's only because I'm the one who feeds him. <Partly true, but Oscars do enjoy human company.> Those 18" brown Plecs have got to be the homeliest creatures I've ever seen (sorry to all the Plec-lovers). <There's more to Plecs than the "common Plec". Look up things like Panaque nigrolineatus and Pseudacanthicus sp. 'L025'. Some plecs will upstage their tankmates when it comes to looks!> My husband loves them so it's a possibility. I'm open to thinking about it if you think it would break the boredom for the Oscar (I hadn't thought of it that way). At least a Plec wouldn't compete for food or attention. <Indeed not. Quite the reverse, the two would largely utilise complementary food stuffs, while both being open to taking a little of one another's if some was left over.> I'll go through the FAQs/articles and research them here. I haven't before because when I think "plecostomus " my mind sees big blocks of sandpaper lol But there's bound to be others I don't know about yet. <Indeed there are. Planet Catfish is a great web site for seeing galleries of catfish including Plecs.> Thank you once again, seeing things from another viewpoint makes me feel better. My gut instinct after reading your thoughts is to wait and get tall & wide both. I'm so grateful to this website. Mitzi <Good luck, Neale>

Re: Tank height/width for Oscar (Neale?) 2nd part... Clown Loach comp.? �� 9/27/07 Neale, Crew, As a P.S. Neale, I read the articles on the different Plecs, very good information. The only other fish I have a real desire for is the Clown Loach. I've never gotten any because my water is very hard (300 ppm) with a PH of 8 and everything I read says you 'need' soft water with a PH of 6 or so. I discussed my water with you recently in regards to the Oscar and you stated that seldom does a 'soft water fish' fail to acclimate to hard water. Would that hold true for the Clown Loach? Or is that stretching it too far? I know they can get up to 12" but it takes them many years to get there. I've also always read you 'have' to have a minimum of 3, do you agree with that? That would be what I'd really WANT to go into a 180 gal with the Oscar, I'm not sure my water would be acceptable though. I don't feel right "settling" for a Plec (although the Royal Plec is actually pretty) just to alleviate boredom. Thanks for helping me, I'm truly trying not to bother you! Mitzi <Clown loaches can and do thrive when kept with Oscars. Water chemistry is largely irrelevant with Clowns. What they appreciate it swimming space and water quality, both of which you're providing. When kept in groups of 4-6, Clowns become very different fish to how they seem when kept singly in a small aquarium. They scoot about nose-to-tail like Corydoras some of the time, though sometimes they'll turn around and snip at each other, perhaps establishing a pecking order. While they can get to 30 cm or so, that's uncommon in aquaria. A 15-20 cm specimen -- after 7 or 8 years of growth! -- would be pretty good going. Royal Plecs are very pretty, and I have one of my own. My favourite fish, and quite tame in her way. But so destructive of plants! Though she doesn't eat them, she uproots them, and causes me much grief in trying to make her aquarium pretty. This species mixes very well with Oscars. They are delicate after import though, so be sure and look for a nice, fat specimen with bright -- not sunken -- eyes. This actually holds true for all "rare" Plecs. PS. Usually, hard water fish have problems acclimating to soft water, and not the other way around. Soft water fish may nt like hard water, but it rarely does them any harm. But when hard water fish are kept in soft water, you end up with fish that have fungus, finrot, etc. I think it's a question of soft water lacking essential minerals while soft water has a surfeit of them -- it's easier for soft water fish to adjust to excess, than for hard water fish to make do without entirely. There are exceptions, but few. Cheers, Neale> Re: Tank height/width for Oscar (Neale?) 2nd part �� 9/27/07 Oh good-thank you! The thought of actually being able to get some Clown Loach after wanting them so long makes my whole day :-)) They grow slower than I thought, I believe when the time comes I'll find 6 that are almost as big as the Oscar. He should still be under 6" by the time I get the 180 g so finding 5" Clown Loaches shouldn't be too hard. They'll definitely get quarantined also. I've wanted them for so long but didn't think I could have them without an RO unit. If it came down to it I could always get an RO unit in the future if I find they don't do well in harder water. Thank you! What great news for a Friday! Mitzi <Hi Mitzi. Clown loaches are definitely among the most slow growing fish in the hobby. In part, this might be because they're often kept in sub-optimal aquarium conditions. But they do also seem to be simply slow-growing, late-maturing, long-lived fish. Truly, hard water isn't an issue. These loaches are routinely kept by British aquarists, most of whom have to make do with "liquid rock". It's easy to fixate on soft water because it's more true to the natural ecology of many fish. But hard water has a key advantage: it's chemically stable. Fish will usually adapt fine to non-natural water chemistry, but what they HATE is fluctuating water chemistry. Unless you really need soft water, e.g., for breeding fish, then there's no practical advantages to using soft water with most standard aquarium fish. Cheers, Neale>

Re: Tank height/width for Oscar (Neale?) Update 11/12/07 I'm sending the previous correspondence for reference. <Ah, hello again Mitzi!> I fell in love with the Royal Plecs after Neale's emails about them (thanks, Neale!). I wanted one to put in a 180 gal tank with a 5" Oscar (tank is on its way). <Royal Plecs are great companions for Oscars.> I wanted Clown Loaches very badly also so was having a hard time deciding. I didn't want to order fish sight unseen online but had a pretty tough time finding a Royal Plec in my area. The LFS I trust the most said it'd be a 2-3 month wait for a tiny one. <They are somewhat seasonal fish here in England, depending on the exporting season from South America, which seems to be around September time. As far as I know, they aren't bred in captivity.> I happened to run across an Olive Royal Plec a few nights ago at a small out of the way fish shop. <Also known as L027b. A fine choice.> He'd been there a month, was nice and chunky and eating well so I bought him, he's in quarantine. <A well-fed Panaque just demands to be bought! Well spotted. Quarantining this species is always a good idea, though that's more about getting them to eat than anything else. If your specimen is nice and fat, then your work is mostly done.> He's only 3 1/2" though so he can't go in with my (now) 5 1/2" Oscar. I'm 99% sure my Oscar would eat him or die choking on him. Too risky. <OK.> I've decided to just put 2 large common Plecs in with the Oscar, will that be alright in a 180 gal? <Should be.> My LFS said it'd work fine, but I'm concerned about 'Plec squabbles'. <See how things go. Look for signs of fin damage or scratches on the body armour. Mostly, it's squabbling over hiding spaces. These fish are schooling animals in the wild, but in aquaria (i.e., in small spaces) they become territorial. It's probable that mature males are the aggressive ones, since it's the males that guard the eggs and fry in muddy burrows.> I also recently bought 6 tiny Clown Loaches from my trusted LFS, they'll be in quarantine another 2 weeks. <Very good. Again, excellent additions to this sort of big-but-peaceful community.> I'd recently asked Neale about putting Corydoras catfish in with my Severum in a 55 gal. <Should work, except perhaps with tiny Corydoras that could be mistaken for food. Severums are herbivores of course, but they won't turn down an easy fish supper!> I adore the Royal Plec (Oliver Twist) and the Clown Loaches so I bit the bullet & ordered a 6 ft long 125 gal for the Severum, 6 Clown Loaches and the Royal Plec. Is that enough room? <Should be, assuming adequate filtration and aeration, plus of course water changes. Providing lots of hiding places will also be important. I'd be looking at terracotta pots and pipes of various sorts. These big fish (especially herbivores like Severums and Panaque) hammer plants so there's no mileage in planting the tank. But creating use of mock-Ancient Greek ceramic urns and the like can be used to create very attractive and easy to clean systems. I've seen people place airstones inside the urns so that the bubbles dramatically come out of the urns. Coloured lights also work great in these sorts of tanks. The additional aeration will also help with water quality and the stocking density.> Would I possibly have room for 12 Corydoras (trilineatus)? <Yes. Their total mass would be about the same as a half grown Clown Loach!> I'm concerned about there being so many bottom feeders and the fact that Royal Plecs are said to be territorial at times with other bottom feeders. <Royal Plecs ignore Corydoras completely, and likely loaches. Their preferred food is wood and vegetables, so largely they'll be eating different things to the other catfish. It's important not to give too much meaty food to Panaque, by the way. Do read this: http://www.wetwebmedia.com/FWSubWebIndex/almosperffshmonks.htm > If the Clown Loaches all thrive and happened to grow fast in the years to come I could always put 3 of them in the 180 gallon tank with the Oscar. This tank is centered around the Severum, so whatever you advise is best for him is what I plan to do. I want to stay understocked. <Your plan sounds good.> Thank you for listening to my dilemma. Lord knows I don't know what I'd do without your web site. <Glad to help.> PS My husband has been reading up on Dwarf Puffers and is planning on setting one up in a 12 gal tank. He was telling me about this "great article" he'd read in Tropical Fish magazine. I looked at the article and saw the author was none other than Neale Monks :-) I told my husband he's also my new hero with Oscar information-ha! <I'm pleased you both enjoyed the article! TFH is a great magazine, and I'm always pleased with how they lay out and illustrate my articles.> Thank you all for being there and being so wonderfully patient. Mitzi <Good luck, Neale>

Re: Tank height/width for Oscar (Neale?) Update 11/13/07 Excellent! I'm forever grateful for you and this entire site! Both tanks are going to have a lot of stacked driftwood and (what I call) mangrove roots. Just a week ago I was telling my husband how cool an "Egypt" tank would look. I was going to try to make it look like Stonehenge. The Greek-looking urns would fit in great! The fish wouldn't know I mixed 2 different "themes". <Plecs and big loaches just love big ceramic urns and other ornaments. We often assume something "natural" is best, but animals don't really care. So long as it is safe to use underwater (i.e., nothing chemically treated or varnished) you're good to go. Terracotta objects work great. A lot of public aquaria do this sort of thing because it looks so good with the right lights and bubbles. At the London Aquarium, they have aquaria that look like Roman baths, the statues on Easter Island, even harbours with anchors and whatnot. With big fish, a few big ornaments looks amazing, and so much better than lots of little bits of clutter.> The tank has 3 separate tops each with their own light fixture so I can put different colored bulb covers on each of the end ones. I love that idea, thank you! <Over here there's a brand of air pump called Hydor and they have these clever little units that combine powerful spiraling air bubble generators with coloured lamps, so you get a column of red, blue or green bubbles. Another near trick is to place generic halogen spotlights well above the tank (say, 1 meter) and only use plain acrylic or glass as a tank cover. When the light is above the water and focused as a beam rather than a strip, could get the dappling pattern of light we've all seen when swimming underwater. It's a totally different effect to the usual uniform lighting. With a big tank without plants, you can really get creative with the lights, and build up areas of light and shade. Big fish, like Oscars, look incredibly dramatic, because they now look as if they are lurking under the shade of an overhanging tree. In other words, think outside the box.> The Severum is a passive female (named Stewie). I always forget and call 'her' a 'he' though. She's in her own tank because of the fact she *is so passive. She's seems so sweet and protective of the 6 Corydoras she's in with now, one of the reasons I love her so. So I don't anticipate any problems with her towards new Corys. <Agreed. Severums are generally quite mild. You get the odd mean specimen, but most are fine, especially females.> I'm now re-thinking putting two (common) Plecs with my Oscar; one should be fine. <Indeed.> I don't want to have to part with one if they don't get along because I get too attached. <Agreed!> I literally *never* paid any attention to Plecs before your previous correspondence and only thought of them as 'ugly brown things'. I'm ashamed I thought that way now. They're beautiful and useful and come in hundreds of colors. Even the plain brown ones are pretty when you look at their patterns and their broad fat mouths. <Precisely so. The problem with this whole family -- the Loricariidae -- is it is addictive. Once you learn about one or two of them, then you discover the Redfin Cactus Plec, the Queen Arabesque, the Blue-eyed Plec, the Black Adonis Plec, Hypancistrus zebra... there are literally hundreds of species in this group, many of which are superb animals.> I wish they weren't so territorial so I could have a "Plec tank". <That is the problem! They're one-to-a-tank mostly, and many get pretty big. But the smaller ones, like Whiptails and Clown Plecs, are often small enough you can set up groups. Under such conditions, many spawn quite willingly. The fathers are exceptionally good parents and will guard the fry even after hatching.> I'm completely in love with this Royal Plec :-) Thank you for opening my eyes and for all your good advice. <My pleasure! My Royal Plec is my absolute favourite fish and she is so tame and so funny-looking. Even my aquarists who keep marine fish accept that Royal Plecs are special fish with a charm and character all their own. Spend some time reading up on their science, too. They're amazing animals and unique among vertebrates in being able to eat and digest wood.> Mitzi <Cheers, Neale>

High ph, hard water-Oscar �� 09/14/07 Dearest Crew, I have extremely hard water and have 5 freshwater tanks. I don't completely trust dipsticks but I think this one is probably reasonably accurate. It says total hardness (GH) is 300 ppm and total alkalinity (KH) is barely under 300 ppm. We have well water with no chlorine or anything. I took it all with a grain of salt until I tried softening & lowering the ph with buckets of test water. I didn't want to put anything in the tanks until I knew what the end results of my bucket tests were. I've been reading extensively the past 4 wks on WWW about ph (something I never understood until I found your crew). The more I read the more concerned I became. I try so hard to feed the right food for each fish, give them plenty of room, keep ammonia, nitrites and nitrates all always '0' by quick 3-4% daily water changes. I want to take care of them right because they're my little charges and they only have me to do it. My 'newest' fish is my now 4" red Oscar. I've him about 2 months. Lord, I love that wiggly little beggar fish. I care very much for my Severum, Goldfish & Blood Parrots but I'm completely enthralled with this little Oscar. I was lulled all these years by the idea that "stable PH is better than unstable proper PH" but now I'm wondering if I shouldn't have been so complacent. After finally understanding PH & alkalinity I'm worried about my Oscar because I adore him so and my Severum who needs a considerably lower ph. The ph of my 4 day old aerated water is 8 to 8.2, the ph in the tanks runs about the same according to my Aquarium Pharmaceuticals liquid test tube kit. I use pea gravel and inert smooth aquarium gravel in the tanks I'm concerned about, old driftwood, no limestone or dissolving rocks of any kind. I used a 10 gal tub of the aged hard water and put a big handful of peat moss tied in nylon with a bubbler. It's been 2 days now and still at 8.2. I left the peat moss in there and added the recommended amount of "Beckett PH Lower" to it. It says it has 15% citrus acid. The pH immediately dropped to 7 but after just 8 hrs it had already risen back up to 8. That's the reason I tend to believe the test even though it was a dipstick test. This water is well buffered, I just wish it was buffered at 6-7 ph. It's not about to give up and let go of the high ph for any length of time. I can't subject fish to these swings, obviously. Do you think an 8 to 8.2 ph is far too high for my Oscar? (I know it is for the Severum). Your Oscar facts said "Freshwater: pH range: 6.0 - 8.0; dH range: 5.0 - 19.0 was acceptable for Oscars. Yet all the FAQ's always say they need 6-7 ph and medium water. If all other factors in his care are optimal, am I worrying too much or worrying for good reason? HITH disease scares me badly and I want to avoid it at all costs. I don't want to shorten their lives in any way. I read several of (mainly) Chuck's references to mixing 80% distilled water with 20% tap water along with leaving peat moss in the tank. That sounds like something I could easily do with no trouble at all if distilled is safe to use. If it were only my 45 gal Severum tank I could also just as easily get water from my brother's house, no big deal. But my Oscar now has a 90 gal tank and I've decided on a 125 gal long tank the 1st of the year. That's alot of water to be dragging home for water changes. If you think the situation is dire enough I'll do research on an RO unit if I need to. I also worry that if something happens to me or I end up in the hospital and my husband had to do water changes he'd never be able to understand complicated water changes. He could easily do them by aging our plain tap water though (with me shouting orders from my hospital bed-ha!) Could you please let me know if my ph is unacceptable for my Oscar? If it is, I'll do whatever I can to change it the right way. If it's not that big of a concern I can quit worrying so much about it. It seems far too many people start mixing, changing & switching with the "If it ain't broke, fix it till it is!" mindset and I don't want to do that. I apologize for the length of this email. What you're doing for the aquarium hobby is above and beyond the call of duty. I'm so thankful for your website. Sincerely, Mitzi <Mitzi, the first thing to understand is pH is not important. Fish don't feel pH. What they react to is something called total dissolved solids, or TDS. It just so happens that high TDS tends to go along with alkaline pH and low TDS with acid pH. But because pH is "easy" to understand, and TDS is "difficult" to understand, aquarists often focus on pH instead of TDS. The analogy is IQ. People often think a high IQ means someone is smarter than someone with a lower IQ, but the reality is that all IQ measures is someone's ability to succeed at IQ tests. There are lots of very skilled, capable people like surgeons and artists and engineers who don't have particularly high IQ levels, and lots of people with high IQs that do incredibly dumb things and don't have particularly impressive careers. If you want to change the water chemistry in an aquarium, what you need to focus on is the TDS, not the pH. Adding magic potions that raise and lower pH is really wasting time and money. Yes, you can add pH-down products to an aquarium where the water has a high TDS level. And the pH may well become acidic for a while. But what you're actually doing is changing one set of mineral salts to another (through an acid-base reaction). You aren't removing those mineral salts, so you aren't softening the water in any meaningful way. If it really was that simple, people wouldn't be spending $100s on reverse-osmosis water softeners! If you genuinely want to put a soft water fish into a soft water aquarium, you have two options: use RO water or use rainwater. I do the latter, because its cheap and easy, but RO has the advantages of convenience and perhaps greater safety if you live in potentially polluted areas. Like Chuck suggests, I mix rainwater with hard tap water to get the water chemistry I want. But adding pH-down chemicals to the water IS NOT an option, so don't bother. Now, there is some misunderstanding about the water requirements for Astronotus ocellatus. Wild fish are found in a variety of habitats with both soft and moderately hard water. They have also become established outside their natural range (e.g., Florida) where they are living perfectly well in hard, alkaline water. According to Fishbase, which is based on wild, not aquarium, fish, Astronotus ocellatus has a hardness range of 5-19 degrees dH, which places your hard water well within its tolerances. I can also mention at this point that Oscars are routinely kept and bred in very hard, very alkaline water here in Southern England. Wild Astronotus ocellatus may be a little more fussy, but the aquarium strains aren't at all fussed. Looking at your other fish: Severums are found in a range of waters including brackish water, so they don't care. Blood parrots are some kind of hybrid of Central American cichlids, so they actually need hard/alkaline water and tend to be sickly went kept otherwise. Goldfish prefer hard/alkaline water as well. As I've said many, MANY times most fish will adapt fine to a range of water chemistry values -- what matters is stability. In fact, very few soft water fish fail to adapt to hard water; the problems are usually adapting hard water fish (like livebearers and Mbuna) to soft water conditions -- they usually get plagued with fungus or simply die. Changing water chemistry is something to do ONLY if you want to breed a particular species, AND even then ONLY once you are satisfied you understand what TDS, KH and GH are all about and how they interact with the conditions in the tank. If you don't understand them, then don't try and change them. For routine maintenance in display aquaria, stick with the water you have and concentrate on water QUALITY. So, in short, put the bottle of pH-down potion away, and just enjoy your fish. Cheers, Neale>

Re: High ph, hard water-Oscar �� 09/14/07 Neale (and WWM), Thank you thank you for the super fast informative answer! You've really put my mind at ease with such a complete answer. I've no doubt your response will help many people. What a relief, truly. They've all done so well, grown so fast and been consistently active for several years, it was hard to wrap my mind around the possibility that the hard/alkaline water was hurting them. But that's subjective because my own fish are all I have to compare to on a day to day basis. I feel very much relieved after your answer. Messing with their pH is something I certainly didn't want to have to do. I've got dogs, cats, pet sheep, a pet rat, a dove and my other fish but this little $6 Oscar from PetSmart has given me more laughs and relaxation than anything else money could buy. Such intelligence and personality they have! I think doctors should prescribe an Oscar instead of Prozac and they'd have better results :-) Thank you again for your words. Mitzi <Mitzi, glad to be of help. Yes, people do get worked into a lather over water chemistry, but the bottom line is that with freshwater fish at least it is relatively unimportant. Oscars are wonderful fish, and seem truly to have a genuine affection for human companions. There are many stories about people teaching them tricks and games. And yes, the therapeutic value of fish tanks is quite well known. They seem to slow people's heart rates and generally reduce stress. And simply working with animals and plants is just plain good for the soul. So enjoy your animals, and good luck. Neale>

Tiger Oscar Cichlid, beh., sys. - 7/23/07 Hi, I recently bought two tiger cichlids at about 1.5 inch for a 30 gallon tank. The two fishes are on the aquarium floor and do not move, although I can still see them wiggle a little bit. I was wondering if this is normal, or if there is some thing wrong with them? They also haven't eaten anything yet. Thanks for your time, John <Hello John. Tiger Oscars are, as you know, going to grow into huge cichlids that CANNOT be kept safely in a 30 gallon tank. In the meantime though, if any Oscar is not swimming about and not hungry, you can assume something is wrong. Precisely what, I cannot say without more information. What are the water conditions? Hardness, pH, nitrite, and nitrate all matter here. What sort of filtration are you using? Like all cichlids, Oscars are very sensitive to dissolved metabolites in the water, i.e., if you don't do big, regular water changes -- the fish WILL get sick. You're remembering to add dechlorinator each time you change the water? There are no aggressive fish in the tank (Oscars are rather gentle, and easily bullied). What foods are you using? Juvenile Oscars are generally quite outgoing fish, but if the tank has no shade for them, they might feel exposed. Oscars are often mistreated by retailers. Check for signs of parasitic infections. It is common for people to feed them cheap feeder fish, and this gets them infected with internal bacteria and parasites. As you probably know, the ideal diet for Oscars contains no live fish at all, but rather crunchy invertebrates (what they eat in the wild) plus good quality cichlid pellets (Hikari Cichlid Gold is excellent, but there are others). Cheers, Neale>

Water Requirements For An Oscar 5/30/07 Hi, I have a 75 gal. aquarium with one large Plecostomus and I am planning to get one tiger Oscar in the next few weeks. What I need to know is I bought a Tap Water Filter for Aquariums. It came with a bottle of Electro-Right and a bottle of pH adjuster that I use in the water for my community aquarium to make perfect water for them. The directions say to make perfect water for African Cichlids to add African Cichlid Salts and buffers to the filtered water. Does this sound right for the Oscar or is there something else that I should do and also what is the right pH for a Oscar. Thanks for your help. Nancy < Your Oscar originally came from the Amazon basin in South America. Your actual Oscar probably was born and bred in Asia. African cichlid salts and buffers are not needed for your Oscar. Treat the water as you for your community tank.-Chuck>

Re: Water Requirements For An Oscar 5/30/07 Thanks for the quick answer. One more quick question what is the proper PH for this Aquarium. And again thanks for the quick answer. Nancy <Greetings. Oscars are pretty adaptable, and anything suitable for community tropical fish will be fine. The ideal would be slightly acidic to neutral pH (6.0-7.0) and low to moderate hardness. Your Plecostomus will want the same sort of conditions. But really, provided the water isn't excessively hard (over 20 dH) or alkaline (much above pH 7.5) you don't really need to be fussed. Performing regular water changes to keep the water quality good is far more important to their health than worrying about the pH and hardness. Cheers, Neale>

Extended period of not eating/lesions/possible parasites? Oscar hlth., env. - 03/02/07 Greetings Experts, <All.... right> I've been reading the FAQ and I am very impressed with your crew's level of dedication. <Me too> However I've read through a few pages and I'm still not sure on a course of action. I would really appreciate any help you can give. We've been caring for a 12" tiger Oscar (his name is Grouch - get it? Grouch the Oscar? Get it?) <Uh huh... shades of the Muppets> for a few years now - he belonged to a former housemate and has been on "semi-permanent loan" for quite a while, and we have of course grown quite fond of him. He lives by himself in a tank that is somewhere around 60-65 gallons. He has been healthy and happy the whole time and we have never had any problems before. Over the past few weeks, he has stopped eating. At first he was doing the thing where he would spit out more food than he normally does; but by now, I would say that I haven't seen him eat anything at all in well over a week. We feed him pellets only (no feeders), which he has always enjoyed just fine. I generally keep up with weekly water changes (around 40-50%) and vacuuming, although I missed a few weeks in a row recently - not sure if that's related. <Assuredly this is... a "build up" (accumulation) of waste products, derivatives... could easily account for the observed/related behavior> He has always had bouts of aggressive swimming, but in the past few weeks he seems to have gotten into a few "fights" with the large wood decoration in his tank (and lost). He had a few scrapes as a result which seem to be healing. BUT, he now has several spots on the front of his head that have tufts of what looks like mold growing out of them. Is this the "hole in the head" disease I've been reading about, or are these just infected areas that he scraped? <Related... are likely "neuromast" degenerative markings of some sort... environmental...> Either way, is it time to medicate the water, and if so what would you recommend? <Mmm, not time to medicate, but time to get back into and adhere to the previous maintenance routine... Also, I'd try enlarging this animal's diet a bit... perhaps (if you're not too squeamish) a few live earthworms... Mealworms... Crickets...> Finally, I've noticed a few small (as in pencil-point small) creatures crawling around on his skin. They appear as tiny white dots, but when you get up close you can see that they're moving. They also appear on the wood decoration. What the heck are these things, and more importantly, do you think they might be related to his illness? <Can't tell... but these too are very likely positively correlatable with the cessation of water changes, vacuuming... and will "go" as well...> The thing I am most worried about right now is his not eating. How long can this go on for? <Likely weeks> And more importantly, how can I get him to start eating again? <Improved conditions... live foods...> I'm hoping you can help with any info that you can. I'd like to hear what the Oscar specialists have to say before I randomly walk into a random pet store and find some random clerk and just say, "Um, my fish is sick." Thanks for any help. I (and Grouch) thank you. - Chris <Thank you for writing... If there's funds for such, I would invest in a few test kits... pH, ammonia, nitrite, nitrate... I suspect the first has fallen and the latter are over 20 ppm... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm and the linked files above. Bob Fenner>

My 3 Oscars aren't getting along... 1/26/07 I have 3 Oscars (1 Albino Tiger [4"], 1 Tiger [3.5"] and 1 Red [2"] all in a 47 gal. tank) <Trouble... not enough room, one too small...> and the albino (Whiteout) and the tiger (Butthead) are getting along but they keep leaving the red (Beavis) out of their activities. Whiteout and Butthead, I think, are a pair from what I have researched, they stick together and explore the tank daily hardly leaving the other's side. <Territorial animals... a 47 is too small...> Beavis is kind of a solitary guy and he tries to get along with the two but whenever he gets too close, the two take turns butting him in the side. Only when it comes to feeding do they get along and it's the better hunter who gets the feeders <A very poor idea... see WWM re> (which is usually Whiteout). I want to know what to do with them and should I introduce another Oscar so that Beavis can have a mate? <Mmm, no... need to remove the smallest fish... pronto... or it will be killed> I've read the other FAQ's on your site and I do not want Beavis to be stressed and so far he isn't showing signs of that yet. Thanks, Nicole <Another tank... eventually a much larger tank... Please read here: http://wetwebmedia.com/FWSubWebIndex/oscars.htm and the linked files above. Bob Fenner>

Fighting Oscars Are Getting Hot 12/24/06 I have two four-year old Oscars in a 90 gallon tank with a Pleco. Up until about six months ago, I had three, and, periodically, they would do frequent battle, sometimes nearly to the death for at least one, but all had their turns at coming out on top and on the bottom. Just when it reached the point that I had decided to get rid of two of them (I put up a "free Oscar" poster at the local pet supply store but nobody bit), one died mysteriously and after that, there was peace. The other two got along for months with no trouble at all. That peace ended the day before yesterday, when they suddenly started fighting ferociously. They fought so hard and so violently that I fear one or both may have wound up with broken jaws. Neither have taken a bite of food sense and the way their mouths look, and the way they are both swimming about with their jaws hanging down, I am not certain they can take a bite right now. I was wondering why two peaceful fish would suddenly go to war with each other like that. As I have been traveling, I had not cleaned their tank for three weeks (my wife cared for them while I was gone but that care does not extend to tank cleaning) and I wondered if maybe there was a water-quality issue that had caused them to get cranky. This afternoon, I interrupted the continuing brawl to clean their tank and when my skin came in contact with their water, I surprised at how warm it was. So I looked at the thermometer and it was 84 degrees! I try to keep it at 76 and I don't know how that happened, as the setting on the heater was just where it was supposed to be. I have been cooling the tank down slowly and it is now down to 80 degrees. Tomorrow I will bring it down to 76. Could this warm water have triggered the battle? They are still making intimidating feints at each other, but there has been no more of the fierce fighting since I cleaned the tank.Thanks,Bill < This is probably a combination of too much food from an inexperienced aquarist and temperatures rising. Big fish can be pretty tough on aquarium equipment. I would recommend getting a titanium or stainless steel heater for this tank. As the water temps cool down things should settle down.> PS: After you answer this question, I have a green terror question for you. < You may have to wait awhile after x-mas to get a response.-Chuck> \ Oscar Set Up 9/26/06 Hey guys! I found your website to be filled so much awesome info. I'm just curious. What would be the ideal aquarium and equipment for a pair of Oscars? It'll be future reference for me. Thanks a lot and have a good one! Kev <A 100 gallon aquarium with two Marineland Emperor 400 filters. A metal heater set at 78 F. A Python Water change system for doing 25 gallon weekly water changes. Large Spectrum pellets for food.-Chuck>

Can you recommend a filtration for an Oscar tank set-up? Hi Bob! <<Hi, Kristi. Tom with you, actually.>> Love your site! It has really helped in my research of starting up an Oscar tank. <<Glad to hear we've been of help so far.>> I am a seasoned vet at raising and maintaining a community fish tank, now I want to try my hand at an Oscar tank. <<A worthwhile project, Kristi.>> I have a 42 gallon tank that I have set aside for this purpose. It is an Eclipse tank and filtration system. <<Might not seem like it on the surface, Kristi, but 42 gallons is a bit small for an Oscar. Maintaining optimal water conditions become a bit problematic and the smaller, relatively speaking, sized tank is likely to increase aggressiveness and territoriality issues. A 55-gallon tank is really a better size here.>> I have read many articles on filtration, i.e. internal and external filters. I read up on a filter that has a built-in heater. Are these better? <<Likely the one of the Eheim Thermofilter models. You'd be hard-pressed to find a better filter, in my opinion. Having the heater "self-contained" has the obvious advantage of maintaining more uniform tank temperatures by returning water to the tank straight from the heat source. Tends to eliminate hot and cold spots that can occur with conventional heaters.>> If I have this size tank, what size GPH should I look for in a filter? <<I'd look in the 250-300 GPH range, Kristi. This would give you 6-7+ full-volume exchanges per hour.>> I only want one Oscar, one convict and one pleco to reside in the tank. Would these overcrowd the tank in the future? <<I believe you should consider not adding the Convict Cichlid. Here, again, I'm returning to the size of your tank. The Convict and the Oscar might get along in a much larger environment - though even this is up for debate - but in a 42-gallon tank, I'd practically guarantee a fight. The Oscar and the Pleco should do okay together, though.>> Would they be good tank mates if placed in the tank as babies? <<The Oscar and Pleco will, yes.>> Should I only add one at a time after cycling the tank? <<I would add both, together, as juveniles. Were you to add one before the other, the order would be the Pleco, first, followed by the Oscar. This would reduce any issues with the Oscar rapidly making the entire tank "his" territory.>> Thanks for your help! Kristi <<Happy to do so, Kristi, and best of luck with your new venture! Tom>>

Tank for Oscars 9/6/06 Hi everybody (with Dr. Nick from the Simpson's accent)! Just wondering how big of a tank a group of six Oscars (space for full grown) will need, better in l x w x h then gallons. -Jack < You want a tank with lots of bottom surface area. Stay away from very tall tanks. At a minimum you want a 150 gallon tank. Bigger would be better. Especially if a pair decide to spawn.-Chuck>

Will a single Oscar get lonely? 9/4/06 Hello! <Hi there> You may have answered this, but I was wondering if just one Oscar would get lonely by itself? <Not likely... has you! As company> I do not currently own a large tank or an Oscar, but I like the idea of one Oscar with plenty of room for itself. However, I don't want to be cruel to an animal that would prefer companionship. Is one okay? <Yes> How big would one Oscar get alone? <About the same size... a foot or so> How big a tank should I get? <The bigger the better... at least forty gallons... sixty or more...> Thanks--I just found your website tonight and it's great! Dorothy Wilson <Thank you for writing, sharing. Bob Fenner>

My Oscars are living in spite of me 8/25/06 I have a display tank in my office ( 13 inches across, 9 inched deep, 48 inches high - 30 gallons) and 2 new Oscars ( a tiger and a red Oscar) <Not enough room...> My clients told me to get Oscars... they told me to give them feeder fish. <A very poor idea> They told me not to worry about cleaning the filter too much , or changing the water every week. I've listened to them , and the Oscars are fine ( I thought swimming up and down would be a problem, by they are fine) After reading the faq's , I see I'm doing everything wrong. I only have time on Sundays to do anything more than 5 minutes of work. Where should I start? ;-)avi <Regular water changes... weekly, stop feeding feeders for all the reasons stated on WWM... Look into larger quarters... Bob Fenner>

Re: My Oscar, Sys., seashells best at the seashore 8/1/06 Hmm.. I sent you an email earlier today, asking about my new Oscar. I know on your web page it says read and you'll more than likely find what you're looking for, and I think I found one of the answers to one of the questions I had asked. (the one about why my new Oscar lays at the bottom of the tank) I still am curious as to whether sea shells are good for the tank or not. <Generally not useful for freshwater systems on two counts: they too-likely change water quality by dissolving... to conditions you don't want. And secondly, the shells sharp edges are too likely to physically damage the fishes> they're pretty, but If they are harmful I'll take them out. I have two in there. so there's not that many. Anyways...one more question, and sorry for the bother: I currently have a 10 gallon tank with a two inch or smaller tiger Oscar. I know that is probably two small. <Yes, will need more room... soon> but it's all I can have right now. When should I upgrade to a larger tank? <ASAPractical> What size of Oscar is considered too large for my tank? Thanks. <Likely at 3 inches or so... Bob Fenner>

Frightened Fish, Oscars 7/11/06 <<Hello, Krista. Tom with you.>> I currently have two Oscars and a pleco in a 55 gal tank. I have had them for about two months. At first they were extremely friendly. They would swim to the front of the tank when I came home from work and were friendly towards each other. <<Okay.>> Recently they seem to be extremely frightened by any movement at all. They will come out when I feed them but hide immediately after. I am thinking of taking their favorite hiding place out of the tank and rearranging some things. Is this a good idea or is there anything else I can do? <<Like taking a sick child's temperature, the first thing I would recommend is looking to your water conditions/parameters. Cichlids certainly like their hiding places and retreat there when feeling stressed. Since Oscars can be pretty outgoing animals, particularly when they recognize the person who provides the "yummies", I'd be looking for the reason that they now seem fearful of movement outside the tank. Sounds like there's more than meets the eye here, Krista.>> I don't want to stress them out but I don't want them to hide all day either? <<As a rule, I try to bear in mind that the tanks are my "displays" but they're my fishes' homes. Your pets have nowhere to "run" so taking away their "sanctuaries" will likely make matters worse. Again, I'd look at what's going on inside your tank before rearranging things. Specifically, I'd look to see if there are parameters that are in serious fluctuation like hardness, pH and temperature. Is there a possibility of an ammonia, or nitrite, spike that you might not be aware of? Even nitrate levels are something to be considered with these fish. Unlikely that this would manifest itself after only two months but do you feed them a varied diet? This is a misunderstood and very underestimated source of problems with fish. Even high quality foods, when there's no variety, can lead to health/stress problems. Usually these don't show up for quite some time but let's look at all possibilities here.>> Thank you Krista <<You're welcome, Krista. Tom>>

Very Spoiled Oscar Questions, nod to Sab, 6/13/06 Hi! I hope there isn't a limit to the number of emails a person can send? <Heeee! I wish there were a number to those I answer!> I think this is my 4th. Thank you for all the great information and advice you have on your site (even the "bad" news kind). Also, please forward my thanks to Sabrina. <Ah, will do> She answered an email about my female Betta Splendens last month. Sadly, she died, but at least her last days were in water that was only dechlorinated, with a little API aquarium salt added. I'm sure it was easier for her, if dying can be considered easy, than being in the 'toxic soup' of medications I'd been subjecting her to. I just wish I'd emailed sooner! My email today, is in regard to my husband's Tiger Oscar, Vinny (Astronotus ocellatus). We've had him about a month to six weeks. He was about 2 inches when we got him, and I'd estimate him to be 3 & 1/2 to 4 inches now. He is in a fully cycled 30 gallon tank. Now, I know this is the part where you start getting annoyed, followed by cursing under your breath, possibly yelling at my email, perhaps making rude gestures, and finally in utter frustration, banging the keyboard against your head, but please bare with me..... <Heeeeeee! Larger tank please> The tank was cycled, and then inhabited by, 3 Dwarf Gourami, 12 Corydoras Catfish (mixed), and a school of 18 Harlequin Rasboras prior to Vinny's occupancy. I had nightmares about the 'cute baby Oscar' eating my beloved Corys <You are/were right to be concerned here> when my husband told me he wanted an Oscar, so I made the deal that we'd up grade the community to larger digs, and then he could have an Oscar. The tank had/has a Rena Filstar Xp2 (300/gph) and a Penguin 350 dual BioWheel (350/gph) for filtration. When we moved the 'community' we left the filtration, just took the fish and their decorations, plants, etc. The Xp2 is running with 4 foam filters (2 - 20 ppi, 2 - 30 ppi) on the bottom, and a micro-filtration pad on the top. The center is all bio-media, consisting of a mix of Filstar's Bio-chem Stars, Fluval's bio-cylinders, and Aqua Clear's Bio-max stones. The 350 has one Aquatic Gardens replacement filter (the kind with the mechanical pad around the carbon - looks like three stacked pillows and a blue bio-sponge all inside a frame). In addition, there is a net bag with Seachem's Biostones, the wheel from a now defunct Penguin 150 (it was fully mature, and I didn't want to lose the colony on it), and 2 Fluval 1 Plus foam sponges (had them, don't have the unit anymore, so figured why not). The water flows freely to both sides, so the media compartment is full, but not stuffed (no overflow, good, steady and even, return water from both sides). I also have a Whisper 60 air pump (with backflow valve) hooked up to/running a 4 inch airstone bar, a 3 inch airstone circle, and a simple sponge filter (for 25 gallons - "maturing" it for use, when needed, in a sick/quarantine/fry type applications). <Good> The tank has two 75 watt heaters (one on each end). For decoration Vinny has two 10 inch (diameter) fake water lilies floating on the surface (he likes to sit/float/hover under them). He has about 1/3 of the bottom covered with around 1/2 to 3/4 inch of gravel and smooth 'river' rocks, the rest (mostly under the log) is bare. The gravel and stones cover the two air stones, which form a nice bubble-wall across the end of one side of the tank. He plays in the bubbles daily. Lastly, he has a large fake log. It's a very large log! It takes up about 1/2 of the bottom of the tank from side to side, about 1/4 to 1/3 the height, and 2/3 of the bottom from front to back. It's open on both ends and has a hole in one side toward the center. He'd had a small flat top cave the first couple weeks, but was already outgrowing it. I guess my husband figured the new log would last him a lot longer! He gets a 50% water change weekly. <I'd restrict this to about a quarter per week/time> I use Tetra's Aqua Safe OR Kordon's Nova Aqua Plus + OR Seachem's Prime, to condition the new water, which is matched to the tank water's temperature. I also use a dose of Hagen's Cycle, API's Stresszyme, Mardel's A.C.T., OR Seachem's Stability with each water change. The filters are serviced bi-monthly, alternating weeks (i.e.: week 1 the 350, week 2 the Xp2, week 3 the 350, an so on). <Good practice> I rinse the pads/foam in discard water only. I replace the Xp2's pads alternately every other month (1 30ppi and 1 20ppi is new and the other 2 are mature at any given time). The micro pad I change every two weeks, since it doesn't rinse well. I usually leave the bio-medium alone, or do a light swishing in discard water (while it's in the basket). I don't normally replace it, should I be? <No... should last for years... with the occasional rinse...> I replace the 350's filter (mechanical/chemical) part every two weeks, but just rinse the bio-sponge. The rest (150's BioWheel, Fluval Sponges, etc) I usually leave alone, other than to rinse them at least monthly (again swishing in the discard bucket). In between water changes we also have an Eheim battery operated hand vacuum than I use to help contain the mess Vinny makes (which is also why he doesn't have full gravel, so I can see when he has build up) He gets fasted for one 24 hour period weekly. We feed him Hikari's Cichlid Staple mini pellets, Hikari's Cichlid Gold mini pellets, HBH's Super Soft Pellets with Krill, Tetra's Baby Shrimp (Sun dried Gammarus), Hikari's Freeze-dried Ocean Plankton, and Tetra's Food sticks (the smaller ones). I make sure he gets three of the Cichlid pellets twice a day (6 total between the Gold and Staple), along with one mouthful of the Plankton after the pellets, each of the two feedings. My husband usually gives him the HBH soft pellets and/or the baby shrimp "snacks" two or three times a day. I try to limit the "snacks" to one or two pellets and one or two of the baby shrimp, but I'm going on trust that he's not sneaking Vinny extra. Since Vinny can move around the tank, and hasn't quadrupled in girth, I'm assuming he's not being overfed? Should he be getting more? I imagine he could bolt down a lot more in 2 or 3 minutes time. He usually only gets the food sticks (2) at the meal before his water change. He's very piggy with them, and has been know to 'spew' chunks all around him so he has room for the second one. Then he goes around and picks up the chunks after he's finished the second one. Out of necessity, we've been getting more accurate on guessing whether he's had time to finish the first one, or not. He has two 'toys' in his tank. A golf ball size whiffle ball (hollow with lots of holes) that he pushes around, chases when it's in the filter current, or pushes into the glass to get attention (my husband unwittingly reinforced that habit). He also has a plastic plant. It has a small (non-toxic) weight wrapped around it's base, to keep it on the bottom of the tank. He lays next to it, and moves it a little, but seems to like the ball better. I use 5 in 1 stick tests (Mardel or Jungle) 3 to 5 times a week, and do liquid tests twice weekly. I test for ammonia, nitrites, nitrates, and pH. The stick does GH and kH as well. I do the liquid GH and kH tests once every 4 to 6 weeks. His tank tests are: Ammonia: 0, Nitrites: 0, Nitrates: 20-30ppm (usually 20), kH: 11, and pH is 8.0 by stick and liquid test and 7.8 per the electric gadget my husband got (not sure I trust it). His temp. is stable at 77/78 degrees (have a thermometer on each end). I also have a Seachem ammonia alert badge in the tank as a backup. So, if you're still with me, my questions are: 1. Is it possible to keep him in the 30 gallon, meet AND still exceed his needs, or are we doomed to failure? <Will need to be moved to larger quarters in time... You might use the limit of 20ppm of nitrate as a guide as to when...> 2. Do all Oscars try to damage/eat/rearrange the equipment in their tank? <Oh yes...> He's shown no interest in the heaters, thermometers, ammo. badge, filter intakes, etc. Is it wishful thinking that he won't start tearing the tank up? <Likely so> I'm not counting the gravel, he can move it to his heart's content. I look at it like the 'tank is for him, not for me' line of thought. If I wanted a 'garden' I'd dig one in the back yard.... wanted a pretty picture, I'd hang it on the wall, sort of thing. I'm mainly concerned about him hurting himself...... Vinny vs. Electricity...... doesn't seem like it would have a great outcome. 3. Can a fish get burned on a submersible heater? <Yes... more possibility of breakage, electricity troubles here though... When this fish is larger, in its bigger quarters, there are ways you can remote or surround the heater/s to avoid such> I've seen things about putting a piece of pvc pipe over the heater? Would an in-line heater in the canister's return line be a better way to go? <Yes... as stated, will want to do with move to a bigger tank... when Vinny is larger...> 4. What other kinds of 'toys' are safe/suitable for an Oscar? <Most anything plastic...> The plant was a no brainer, as it was aquarium safe. The whiffle ball was harder, but since it wasn't colored, was too big to swallow, too small to scare him, and light enough not to break/crack the glass, we let him have it, after I'd thoroughly rinsed it in hot water. However, finding other items hasn't been working out. My husband wanted to look at dog and cat toys or baby toys, but I talked him out of it, since most are colored. I convinced him the dyes in the plastic could be toxic when mixed with Vinny's water.... baby safe isn't fish safe.... so to speak. Was I wrong? <Mmm, "baby safe" is likely okay, chemically inert> 5. Can you estimate/guesstimate how long he'd be better than 'okay' in the 30 gallon? <Six months perhaps> For instance, if he only gets to 10 inches, would he be okay to stay in it? <Mmm, no... will likely want to move when 4-6 inches...> 6. I have an extra filter, a Fluval 3 Plus internal filter (185/gph), should I hook that up in his tank as well? <Could> Is there anything else that I can do to keep him in the 30 gallon longer/permanently? <Mmm, if absolutely necessary, an experiment... could continuously to almost continuously change water... to reduce metabolites and their ill effects> A larger tank is not an option right now. When it was safe to do so, we added new members to the new 55 gallon 'community' tank, so they can't go back into the 30 gallon. We have 6 more Harlequin Rasboras (total school of 24) plus the 12 Corys, and 9 mixed Platys. The three Dwarf Gouramis were moved to a 20 long, along with the male Platys (THAT is another long story). We don't have room for another 55 gallon (or the money for that matter). Returning Vinny is not an option, my husband is completely attached to him. Any tips, pointers, suggestions, etc would be most appreciated. Thank you!! <I strongly suspect that you two are "evolving" your hobby into more advanced groups of fishes... will either "find room" or move the Oscar to the 55... Can saltwater, reef systems be very far ahead? We'll see. Bob Fenner>

Very Spoiled Oscar Questions, nod to Sab, and a nod back - 06/14/2006 Hi! I hope there isn't a limit to the number of emails a person can send? <Heeee! I wish there were a number to those I answer!> I think this is my 4th. Thank you for all the great information and advice you have on your site (even the "bad" news kind). Also, please forward my thanks to Sabrina. <Ah, will do> <<I'm glad to have helped, or at least glad fo having tried to help.>> She answered an email about my female Betta Splendens last month. Sadly, she died, <<I'm so sorry to hear this, Heidi.>> but at least her last days were in water that was only dechlorinated, with a little API aquarium salt added. I'm sure it was easier for her, if dying can be considered easy, than being in the 'toxic soup' of medications I'd been subjecting her to. <<I'm sure you made her as comfortable as possible.>> I just wish I'd emailed sooner! <<No worries.... We do what we can. You did the best you knew to do. I'm glad you wrote to us at all, and gave us and yourself a chance to learn together. Wishing you and all the lives in your care well, -Sabrina>>

My Oscar, beh., systems 6/13/06 Hmm. I'm new to the raising of Oscars, and I have not actually had mine for more than two weeks, but I have some questions to ask that I couldn't find in the FAQ, or if the answers are there, I overlooked them. I have a tiger Oscar, barely two inches right now. He's in a 10 gallon tank, and I'm working on getting a larger one soon. <Good> The water balance appears suitable for him but he's shy. He hides at the bottom anytime I am in the room or the lights are on. <Still just getting used to your setting... This fish will become more outgoing in time> He eats, but only after I leave the room. (I know this because the food will be gone when I come back a few hours later and they won't be stuck in the filter.) I also know that Oscars are messy fish, so I clean the filter and the tank (never doing a full water change) regularly. I feed him Hikari Oscar pellet food. is there anything I'm doing wrong? <Not thus far> Or is it normal for a Oscar to do this for a couple of weeks until it is comfortable in its new tank? <Yes> I keep the water at 74 F.. and the only stuff in the tank with him are rocks and shells. Are the shells bad for him? <Possibly. I would leave these out> I keep a pleco in there as well.. <This fish also needs much more room...> and he leaves it alone.. I don't know. I would appreciate some insight, even if it's to tell me I'm being dense and there's no problem. Thanks. <No worries... Bob Fenner>

Re: My Oscar 6/13/06 I appreciate the quick reply. It really makes me feel better to know that, other than the too small tank, the fish is behaving normal. Thanks very much! (I removed the shells too) ~Jennifer <Ahh, good and thank you for sharing. Bob Fenner> Future Oscar tank 4/26/06 I currently own a 225 Gallon tank that used to house a my tropical community fish. A few years ago I had to go overseas for work, so I gave away/sold all the fish to friends with healthy and compatible aquaria in an effort to provide them with good homes during my absence. I have recently returned and have no intention of leaving again. This time around, I want to set up an Oscar tank. However, since I have never kept cichlids, I am endeavoring to do all the necessary research on the subject before I set up the tank again and go out to buy fish. Here are my questions: 1. I would like to house 2 Oscars in the tank. What do you suggest as the ideal number of Oscars for a tank my size? < About 100 gallons if they get along.> 2. I find the common Plecostomus endlessly amusing and would like to include one in my tank. Is this too much bioload? If not, what size pleco should I buy to ensure that the Oscar doesn't grow large enough to eat it? (I plan on buying 1-2 inch Oscars) < The regular pleco gets over 12 inches long. Get one about 4 to 5 inches long with a couple 2 inch Oscars and the Oscars will never get big enough to eat them. With good filtration and regular water changes they will be fine.> 3. Most importantly, I would very much like to have an albino tiger Oscar. You mention that they tend to be less aggressive and might have trouble competing for food. Is there a way of overcoming this? Are there any more albino-specific challenges to be aware of? Light sensitivity perhaps? Decreased longevity? < Albino Oscars may not grow as fast or as large as normal colored Oscars. When mixed together the normals almost always seem to dominate.-Chuck> I do look forward to hearing from you, and thank you in advance for your time. Shankari Adding An Oscar To a 55 Gallon Tank - 03/12/2006 Hey, I currently have a 55g Freshwater Tank with the following inhabitants: 12 inch Plecostomus 10 inch tinfoil barb 6 inch Bala Sharks (2) 8 inch Senegal Bichir 6 inch Columbian Shark 4 inch Cory Catfish What would I have to do to be able to house one Tiger Oscar? < Not recommended. Your Bala sharks and Colombian shark are still growing and your 55 gallon will soon be too small even for them.-Chuck>

Oscar health question ... more systems- 2/28/2006 I am new to the wonderful world of fishes. And have recently purchased an adorable little 1.5 inch black with white stripes Oscar (no idea what type tag on the tank said fancy Oscar). <All are the same species... as with domestic dogs...> My worry is that normal fish swim with there body remotely flat like - my little guy swims at an angle close to / (Sorry only way I can describe it). it��s how we swam when I purchased him I want to know if he is ill with anything or if this is normal? <Small Oscars do "wag" a bit in swimming> I have tried looking online and asked at the pet store (they looked at me like i was stupid but couldn't help me). I came by your web site and found it to be the most informative and helpful site i have found. Please let me know if you think something is wrong with him what it is and what I can do. Right now he is in a 10gal tank (upgrading to a min of 75g as by the end of the year) He has 3 tank mates 2 1.25 inch Jack Dempseys and a 4.5 inch pleco everyone gets along fine. <Do keep your eye on the Dempseys... the behavior you describe may be largely "submissive" re their presence> Will these fish have issues when they get bigger? <Yes... much more so in crowded confines> Or do you think they should be fine in a 75g tank. Thank You for taking the time to answer my questions Robert <Should be fine there for a good long while. With careful observation, you should be able to discern whether trouble is excessive. Bob Fenner> Setting Up An Oscar Tank 1/11/06 Hi Crew. I now have two successful tanks and a lot of credit goes to your site. Planning on setting up my third tank This will be a Oscar only tank. Specs are; Tank size- 55g- 3x1.5x1.5, Substrate= 2�� Brown river sand appropriately treated Plants= Artificial, Can I keep live plants? < No> Filter= Internal Power filter, Thermometer, & heater Suggestions & Comments please? Thanks Sandeep R <Go with an external power filter that pumps at least 200gph. Go with an unbreakable heater. Never feed live fish without taking the proper precautions.-Chuck>

Getting An Oscar - 01/09/2006 I am interested in getting an Oscar. I've never had one before. I have tried to research them but, not having much luck on figuring out how to tell the males apart from the females. I also am confused on what to feed them. Some sites say to feed them smaller feeder fish, and other say not to. What do you suggest?? I am confused....... Can you help??? Jess <Oscars get up around 12+ inches so you will need a big tank of at least 75 gallons when it is full grown. They are messy cichlids so you will need a very good filter too. Get one that pumps the volume of the tank at least 3 to 5 times per hour. I would recommend an outside power filter. Water should be around 80 F. When small feed flakes and small pellets. Larger fish could be fed earthworms, pellets and frozen foods. Feeders are not recommended because they are living fish that can carry diseases into your tank. Treating a large tank is not any fun. It is expensive, time consuming and difficult on your fish.-Chuck>

Little Tank + Big Messy Fish = Uh-Oh 1/8/06 Great site guys thanks.... <Thank you and your welcome.> I've had two Oscars and 2 Plecos in a 30 gallon tank ( I know need to upgrade) <Hehe, understatement of the new year.> Oscars are still young the larger being 4inches. Everything has been fine with them until 2 days ago no appetite, swimming erratically- vertically, on their side, the smaller seems to have scratches on the fins, and both seem to have a cloudy like film on their entire body. <Indicative of poor water quality.> I haven't seen any ich marks need help....Thanks <Well as you allude to above this tank is quite small for the size and type of animals you have. Plecos and Oscars are very messy critters. I��m willing to be there is some nutrient accumulation going on here, what are your test results for ammonia, nitrites and nitrates? Adam J.>

Oscar Tank 12/22/05 Hi! These are my readings. Ammonia-0 Nitrite-0 Nitrates-5ppm Ph~7.2 Is that a good healthy reading for my Oscar to live in? <Water looks good, what size tank are we talking about? Maybe something around 75gallons or so? -Gage>

New Oscars and Water Changes 12/21/05 Hello, I have a question, I have a 80 gallon aquarium; it has wet/dry trickle filter and 20 watt UV sterilizer. I have cycled the aquarium and put variety of fishes like tetras , sword tails, African and Amazonian cichlids. I used to clean the aquarium and 20% water change every 4 weeks. Now I want to put 2 Oscars in it. But from the websites I found Oscars need weekly water change. So my questions are: 1.With the sterilizer I am still required to change 20% water weekly? < The UV sterilizer kills bacteria and pathogens in the water. You change water to reduce the nitrate levels in the tank. One has nothing to do with the other. Yes you still need to do weekly water changes.> 2. And on every weekly water change do I have put the chemicals like aqua safe dechlorinator, vitamin, stress zyme etc.? <If you have chlorine or chloramine in the water then it needs to be treated or it will be harmful to your fish. Most water conditioners can take care of both but you will have to read the bottle to be sure. For an average aquarium I think that is all you need. When you add the Oscars the tetras and swords are in danger of being eaten.-Chuck.> Thanks

Filtration and Sanity 12/12/05 To whom it may concern, <I'm always concerned, the shrink says that's not healthy though.> I am setting up a 100 gal for two Oscars. I already a Fluval 304 and a penguin bio wheel 305 power filter. I was wanting to purchase one more filter for my system and was wandering if you have any suggestions on which type or brand. <Well what you have seems to be sufficient but if you want my opinion on filtration, I love the EHEIM canisters/wet-dry combo for freshwater use, I would also purchase a few powerheads for some water movement.> thanks for your time. <Welcome, Adam J.> New Tank Setup for Oscars 11/9/05 Good morning! I've consulted you in the past and received some wonderful information on my 29 gal set up. Thank you for all of your advice as things are running smoothly with that system. <Welcome> With that said, I am looking to purchase a 55 gal tank and am interested in Oscars. I have read that only one Oscar can live in this environment. <Ultimately... yes... though a few could be started here, moved to larger quarters down the line... better for this species socially to not be raised solitarily> My question is, can a Pleco also live with this one Oscar or is the 55 gal only suitable for the one Oscar? <Yes to the Pleco addition> Additionally if I were to purchase two Oscars and one Pleco, can you tell me the tank size needed for that? <Maybe an eighty gallon plus in time> I love the idea of having a tank with larger fish. I know with larger fish, come space requirements. I do not want unhealthy or unhappy fishes, so thank you for your help in advance of me purchasing a set up. Anne <Thank you for sharing your plans, concerns. Bob Fenner>

Big Fish For Not So Big Tank 10/21/05 I own a 55 gal tank that houses two Oscars, one tiger about 3" and a red Oscar about 2". I have been watching them and at fist they been just swimming together, now the bigger seems to be dominating the smaller one. Is this normal? < Yes. Cichlids are very territorial and this often happens with two fish in the tank.> I also plan to get a red devil to complete my tank. Would this be advisable since I always had red devils and liked them in my tank. If not a red devil what about a Tilapia butikoferi? < Your 55 gallon will hold one adult fish. Pick one and get rid of or don't get the rest. All of the fish you have picked can get over a foot long over time.-Chuck> Oscars Dig Undergravel Filters 9/13/05 I want to first say that I am impressed by the wealth of information on your site and am very grateful for it. < Thank you for your kind words.> My question is regarding my Oscars which appear to be a mating pair of roughly 7" or so. They often will appear to be performing the normal mating rituals, fin slapping, quivering, and lip locking. Problem is that they don't seem to follow thru with it. They do all those things and then nothing happens, they just stop. I've done some searching in your archives and not found anything that appears to match this situation. Also they often dig at the gravel but don't attempt to clean the flat rock I provided. They dig to the point that the undergravel filter I added becomes exposed, which brings my next question. I've read that the more filtration the better, so I added the undergravel variety. I have recently been told that that was not a good idea, that it doesn't help, and that when the Oscars expose the crate they are allowing what I thought was supposed to be beneficial to come back up and pollute the water. Is this accurate? Thanks in advance. Jada < Your young pair of Oscars are going through the motions. As they get older and more experienced they will ultimately spawn. When the Oscars exposed the filter plates the water fins the path of least resistance and goes through the plates and not the gravel. No filtration is going to happen.-Chuck> Oscars and Tank Size. 9/9/05 I have read through most of your FAQs on Oscars and so I apologize for yet another tank size question. From my research i have found sources saying anywhere from 55-125 gallons is the minimum for 2 adult Oscars. I have a 72 gallon bowfront tank with 2 Emperor 400 filters and a marineland 550 powerhead with a sponge filter attached to it. I would like to have 2 Oscars but I will not be getting a new tank for at least three years, and I don't want "unhappy" fish. Any thoughts you have on this would be greatly appreciated. thanks >>>Greetings Nick, This species of cichlid not only needs space because of it's size, but because of the amount of waste that it produces. They are VERY messy fish, and place a heavy load on the system. In my early days, I had a pair of in a 55, and I would never do that again. I'd say 72 gallons is on the edge, with 90 gallons being the minimum where things are comfortable both form a space standpoint, and waste management standpoint. Keep in mind that no matter what, you need to be doing as much as 50% water changes WEEKLY when they get large. Otherwise organic waste builds up in the water, and you end up with disease problems, most notably "hole in the head" Good luck Jim<<<

Re: Oscars 9/9/05 Thanks for the info, i think am gonna stick with one Oscar. Nick >>>I admire your discipline and regard for your charges Nick, good luck!<<< Oscar Filtration 9/5/05 Hi, I have a red and a tiger Oscar. Both are about 10-12 inches in length. They are in a 120 gallon tank. I have a Cascade 1200. Is this a good filter and is it enough filtration for this size of tank with two fish. < It says it pumps 315 gallons per hour. I would recommend a filter or filters that pump at least 360 gallons per hour. I don't like to use canister filters unless I have to. I prefer outside power filters or wet dry systems like the tidepool by Marineland for big tanks just because they are very easy to clean.> I just got the tiger and I have had my Red for about 2 years and switched from a 50-75( not sure on size) gallon tank to make room for both fish. Before in the smaller tank it would get dirty really fast with the same filter and only one fish. I guess my question is...should I get a second filter and what size would be sufficient. < Start switching to an outside power filter. Look at the Marineland Emperor series.> Also why do the two fish get side by side and shake their tails and fins? < They are communicating with one another.> I'm assuming they are marking their boundaries! Also will the two mate if they are male and female and what are their rituals for this? < They are more likely establishing territories. Breeding starts with the male and female displaying at one another followed by some jaw locking . An area is then cleared and cleaned. The eggs are laid and then the male passes over them to fertilize them> My red is a female I do believe. I think she has laid eggs....little white balls (size of pin heads) in the bottom of the tank where she had moved all the rock to make a flat surface. I saw this happen several times when she was in the tank by herself. But not recently. < That fish is an obvious female that has laid infertile eggs. When the eggs are good or have been fertilized they turn a clear brown color.> Overall the two are tying to get to know each other and have only been together for 3 days now. Is there anything I should watch out for? Main concern is about the filtration. I don't want to have to clean this tank constantly. Thank you, Karen The Emperor 400 should help a lot. When you do your weekly water changes you should vacuum the gravel too.-Chuck> Oscars Act Like They Are Starving 8/31/05 First off. Love the site. Have learned a lot from it. I have 2 Oscars (Pedro & Napoleon) in a 75 gallon. Pedro is about 5 inches, while Napoleon is about 4. My problem is that they like to leap out of the water when I feed them. If I open up the lid and hold my hand over the water with food they will jump up to my hand (Pedro has been about 90% out of the water). And they splash water all over the place! I even got nipped once. It didn't hurt....Do you think they'd bite hard enough to hurt me? < They don't really have teeth but they will get larger and may develop some then.> I like my fingers and want to keep them. One time Pedro must have hit the side of the lid on his way back in, because I saw a section of his scales floating in the water. Maybe he'll learn his lesson? :) Is there anyway to stop them from jumping? I try to open the tank lid really quick and throw the food in and close it fast! But it's kind of difficult because I have a 2nd lid above it on my canopy. By the time the canopy lid is open, they are up top awaiting my feeding hands. Suggestions, comments, or jokes would be greatly appreciated...Dave < Lower the water temp and that will slow them down. Mid to upper 70s F will slow down their metabolism and they won't be starved all the time.-Chuck>

More Cichlids and More Shoehorns, Different Querier - 08/26/2005 I just bought an Oscar about 3 inches long. There is only one other fish in the tank, a 3 inch pleco. The tank is 20 gallons, and I was wondering if the Oscar being in that sized tank by himself well be fine? <No. Both of these fish will seriously outgrow this tank - the Oscar will need a much larger tank in short order.> Please email me back at XXXX. Thank you for your time. -Corey <Wishing you well, -Sabrina> My Tiger Oscar is sick 7/22/05 Hello, my name is Sharon and this is the first time I have had Oscars. I purchased 3 of them from my local pet store and within 12 days one of them had died. I noticed it (not sure how to tell female from male) was not acting normal, just laying around on the bottom of the tank, breathing heavily and not eating. I have a 55 gallon tank that also houses 2 Plecos about 4 inches long. I noticed the sick Oscar had a white frothy bubble of some sort in it's mouth when it breathed, and it was taking very deep breaths. I took it out of the tank and placed it in my beta fish vase.. I figured it was going to die, so I did not want it with the others for fear they would eat on it and get sick too. Now, one of the others is sick with the same thing, frothy bubble, deep breathing, and a thick clear bubble surrounding it's eyes. <Mmm, they do have a clear area...> This one is staying at the top of the tank, pretty much in one area...behind one of the tall plastic plants. I have treated them for ICH first... which they did have. That cleared up. After that, that is when I noticed the other fish get sick. It was fine before then. I have assumed it was some sort of fungus and am treating with ANTI-FUNGUS BY AQUARIUM PRODUCTS once I finished treating for the ICH. It has made my water green. <These "medicines" are toxic...> I did a water change a couple of weeks ago, and have not been up to doing it lately as I am recovering from surgery. Could you please give me an idea as to what is wrong with it, <Is this tank cycled? How is it filtered? There is something amiss with the environment here... do you have test kits for ammonia, nitrite, nitrate?> will the other Oscar catch it, can it be cured, should I just cut my loses and flush the sick one??????? Also, How often should I change my water, and how much? <... this is posted... on WWM> Should I purchase separate kits that test for each nitrate, chlorine, etc? What kinds of medicines should I have on hand? I have also been feeding them Cichlid pellets, flakes and frozen shrimp. Am I doing something wrong? I want to be able to keep these Oscars for many years and allow my daughter to watch them grow, but so far, I am not having that much luck. Please help me!!! Also, I am not sure where to look for your response, whether here or your website, so would you please send an answer to this email address just to make sure I get your help. Thank you. Desperate for help! <Then read... here: http://www.wetwebmedia.com/FWSubWebIndex/fwsubwebindex.htm re Set-up, Oscars... Bob Fenner>

Re: My Tiger Oscar <System> is sick 7/23/05 Bob, <Lexxus> Thanks for getting back with me. I have looked at the site you gave and still have a lot of reading to do, but also more questions. First, you mentioned something about filtration...I have a TopFin 55 gallon tank with a double filter that hangs over the sides, plastic plants and some fun decorations. Right now there is no carbon in the filters because of the medicine in the water. I am afraid my Oscars will not make it even after I have done a water change. They have not moved from the corner of the tank in a couple of days, and not eaten at all. <What is their water quality?> You said the medicines I was using were toxic... but this is what employees at Petsmart suggested I use. What would be better? <... please keep reading...> Also, what is your take on Aquarium Salt? Should I add it or not? <I would> I have seen you mention something about Furnace. What is this and can it be bought at Petsmart? <... don't add anything unless you know what you're doing. You don't> How many water changes should I do to take out this green medicine in my tank, and if my fish die...including the Plecos who are swimming around like crazy, how long should I wait before adding 1 or 2 more Oscars? Please help. Thanks. <Read, don't write. Bob Fenner>

Two Oscars space 7/6/05 My name is Alex, and i was wondering if I could keep 2 Oscars in a 55g successfully? Thanks <Not indefinitely w/o trouble. Please see here: http://www.wetwebmedia.com/FWSubWebIndex/oscarsysfaqs.htm Bob Fenner>

Uncycled Oscar Tank First off I'm sorry if you were asked this question before, but I tried looking it up and couldn't find it so here goes. My bf and I have recently purchased 3 new Oscars, that are approx. 3", 2.5", and 2". He's had Oscars before, but I'm pretty new to the fish game. At the moment we have them in a 10 gallon tank but we're getting a 72 gallon at the end of the week. Anyway, they had these beautiful bright colors when we got them (which is the reason I picked them) but they seem to be fading. The 2.5" was black with them coolest bright white stripes, and now you can barely see them. The other two were the had these colors like the chameleon paint you see on cars, ranging from oranges to purples, only one was like a dark grayish with stripes. Now they look so dull. I feed them cichlid sticks, and they're pigs!! Plus I drop algae wafers in for the sucker. How do we get those awesome colors back? Thank you for your time. <Water changes, lots of them. 50% at a shot. Do two today, a few hours apart. Then daily. Your Oscars are suffering from ammonia poisoning. A result of all the food they eat. Please read here on establishing bio filtration: ; http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm I would get the 72 set up ASAP, but leave the 3 Oscars in the 10 gallon until the new tank cycles. If not you'll soon be doing 50% water changes in the 72. Much easier in the 10. But you can't miss a day. And slow down on the feeding. Oscars are great beggars, but one small feeding a day is plenty. The more food that goes in, the more ammonia comes out. Even skipping a day once a week is better than over feeding at this point. I strongly recommend a test kit to check the water during cycling. It's the only way to know when the 72 is fish safe. Please do a "fishless cycle". I link above will explain all. Don> Oscar Pond 6.14.05 hello. I would like to place my Oscar's in a freshwater ( man made ) pond outside. Is this a good idea, I have treated the water, do I need to do anything else? I live in Houston so it is very hot at the moment Thank you for your time Julian. <Your Oscars will love the additional room (assuming it is bigger than the tank), natural lighting cycle, and any bugs that venture near the surface of the water. Keep an eye on the temperature so long as it is within range, and you have good filtration on the pond you should be in good shape. I am also assuming that this is your pond and not a public pond or something similar, that would be a bad idea. Gage>

Moving Big Fish Hi Bob - I wanted to ask you what is the best way to move an Oscar fish into a larger tank. My Oscar hates to be moved and the last time jumped out of the tank and onto the floor. He jumped out one other time when I went to feed him and he really tears up his skin when he does this. We have tried netting, pouring, etc. and it is just a huge nightmare in my experience. Is there an easy way to do this? Any information that you could give me would be greatly appreciated! < Big fish require big nets. Many fish stores don't carry nets big enough to do the job right. I would recommend a net as least twice the size of the fish So a 1 foot Oscar needs a two foot long net. You will probably have to go to a bait or fishing supply store to get that big a net. I would remove all the rocks and things that he could hurt himself on. Then turn out the lights and let him fall asleep. After a couple of hours then sneak back in and slowly catch the Oscar. Taking him out of the water should be easier in the bigger net. Obviously he will be wide awake when taken out of the water. Set the net in the new tank and allow him to swim out. <<RMF would just scoop out this and other large FW fishes with dipping in large, thick plastic bags... much less scrapes>> Don't just plop him in. Keep the tank dark for a few days and approach him slowly for awhile until he gets accustomed to his new surroundings.> Also I know that you don't recommend feeding Oscars the feeder fish, but there are time when that is all mine will eat. How many and how often should they be fed the feeder fish if that is all they will eat at the time? Thanks!!!! < I still stick to the old rule that feed him once a day and only enough food so that all of it is gone in two minutes.-Chuck> Oscar Bumped His Head, Now Afraid of Dark? Rapid Light Changes Hello, I'm quite concern about one of my Oscars. (I had them for about 3 months) About two weeks ago we moved my Oscars (2) from a 10 gallon tank to a 55 gallon. For the first week they seemed to be doing very well and loving there new home. One of my Oscars (my larger one) has had some missing fins since the first week we had him. Last week while at the pet store, I found some medication that was suppose to help with fin growth and repair. I started to apply the medication to the water last week Tuesday. Since last week Wednesday, my larger Oscar stopped eating and was very unsociable, hiding behind rocks and plants. My smaller Oscar is doing perfectly fine. I just figured the larger one was not feeling well and decided to leave him be for awhile. Over the weekend he still was being the same, so we did a 20% water change, but still no change in the larger Oscar. Then last night after eating supper, I was going to check on the Oscars, and could not find the larger one and then finally found him on the floor. We only have one tiny little opening on the tank and I'm quite amazed that he was able to fit through it. After we put him back in the tank, I'm notice that his scales around his eyes were all scraped up. He seemed to be very disoriented for awhile swimming vertically. After a few hours passed he seemed to be coming around. I tried to feed him again, and he still will not eat. Just before bed time, I went to turn the light off and he went crazy (swimming totally fast back and forth throughout the tank hitting all objects in his path). I was total freaked out over this and quickly turned the light back on. He instantly clammed down. We have a water testing kit and have been checking it daily. The water seems to be perfectly fine and so does my smaller Oscar. I just have no idea what's going on with my larger Oscar. Any help is must appreciated. Amy <Your answer is actually the title I placed on your question. Fish don't like "lights on-lights off". I think they have difficultly with their eyes rapidly changing from bright light to darkness and visa-versa. The trick is to place a small Christmas tree bulb sized night light on the same wall as the fish tank try turning the room lamp on first before turning on the fish tank light, and then turn off the fish tank light first before turning off the room light. It should make a difference.-Chuck>

Hurt Oscar - Rapid Light Change Follow-up Thanks Chuck, What should I do about the larger Oscar not eating? Its been about a week and 1 day now that he has not been eating. This worries me because he used to be the one that was always starving for more food and would often jump at my hand when it was feeding time. Also, he is very unsocial able now, where before he stopped eating he was quite entertaining. He doesn't even seem like the same fish anymore. The only thing that we did differently in the last week before he stopped eating was give them the medication for the fin repair and we fed them two goldfish as a treat which they haven't had in quite some time. I don't believe it was the medication because the smaller Oscar is doing perfectly fine. And I'm also afraid that he was injured in his jump out of the tank. He is missing a lot of scales around his right eye and on the tip of his head. Will these scales grow back?? Also, do you think that the larger one might have gotten sick from the goldfish? If so, what would you suggest that I give him to make him feel better and to start eating again. The last couple of days I've fed them flakes, frozen blood worm, frozen shrimp brim and pellets. The smaller Oscar eats like a pig and my larger Oscar just looks at the food and swims away. Amy < The larger Oscar took a pretty good shot to the head when he jumped. He knows he is hurt and so do the other fish. I would place him in his own tank for awhile until he heals up. once the wounds are healed he should start to come around.-Chuck

Oscar systems, feeding, Gage's go Hello there, Thank you for your web-site it is an easy to navigate wealth of knowledge. I have spent over an hour reading trying to narrow down my problem I have, what I believe is, an albino Oscar. He/She is white with an orange "knot" on s/he head and tips of fins. He is about 6 inches tall and about 10" long. I have had him for 5yrs now, and bought him when he was about 2". (He was sold to me as a semi aggressive). He has since killed all the other semi aggressive that I had! So he is now the only one in the tank. No matter what he is, I just adore him, he is our pet, and I have become concerned with his well being. From the readings, there is a lot I should be doing that I have lucked out and never had to. I am just concerned on where I should start. I did a complete water change last week. I also replaced the air tubing for the underground filter system, and bought a new over the tank filter. Lots of changes here, so I wonder if I haven't stressed him out. As a treat, only the third time I have ever offered, I put in 12 feeder gold fish. If he has eaten any of them it was only one, as I now count 11. But I don't know if that was done here or at the store. The water was cloudy on the first day after the change so I added some Stress coat to my 50 gal tank. The water cleared up beautifully. Now I want to give my fish a hug. He seems depressed almost afraid of the gold fish. He has always been "moody" after a water change, but only for a few hours. I changed his water last Tuesday and he has not snapped out of it. He mingles at the bottom of the tank in one corner or another. He still comes up to see me for feeding, but he is not nearly as perky and playful as usual. After eating about 5 pellets he meanders back to the bottom. He is not playing with the goldfish at all...the goldfish are not even afraid to go eat his pellets in front of him!! It is almost as though the goldfish are bullying my Oscar!! I see suggestions of Epsom salt, live worms, and water testing. I have never done any of those things. Where should I start??? I do not see any visible fungus, or sickness. His eyes and fins look good at this point, although the water seems to be getting a little cloudy again. By the look of the water, it seems like maybe his natural slime is falling off?? He still comes up and "kisses" at me and my children when he is visited. He just seems sad and sluggish. I want to catch whatever it is before it becomes a bigger problem. Please advise on where I should start to diagnose our pet. Thank you so very much for your time and your website. I look forward to hearing from you. Jessica <Hi Jessica, glad to hear you are learning what is best for your fish and correcting past mistakes. Most likely the 100% water change is what stressed out the fish, that is a pretty big shock. The slimy weirdness in the water may be from the stress coat. Feeder goldfish are not a good idea, for a treat I might pick up some frozen krill from the pet store, or even yummier big fat worms from a bait shop or a hole in the back yard. Feeders can introduce parasites, fungus, all around nastiness to your tank. Just keep up on weekly to bi-weekly water changes and watch for signs of sickness (fuzziness, weird spots, open wounds, etc.). He should return to his normal behavior in no time. Best regards, Gage> Oscar systems, feeding, Bob's try Hello there, Thank you for your web-site it is an easy to navigate wealth of knowledge. I have spent over an hour reading trying to narrow down my problem I have, what I believe is, an albino Oscar. He/She is white with an orange "knot" on s/he head and tips of fins. He is about 6 inches tall and about 10" long. I have had him for 5yrs now, and bought him when he was about 2". (He was sold to me as a semi aggressive). He has since killed all the other semi aggressives that I had! So he is now the only one in the tank. No matter what he is, I just adore him, he is our pet, and I have become concerned with his well being. From the readings, there is a lot I should be doing that I have lucked out and never had to. I am just concerned on where I should start. I did a complete water change last week. <Mmm, best to avoid such complete change-outs... restrict these to a good 20-25% maximum... too much change too soon is bad... and source water can be dangerously variable in quality> I also replaced the air tubing for the underground filter system, and bought a new over the tank filter. Lots of changes here, so I wonder if I haven't stressed him out. <Possibly> As a treat, only the third time I have ever offered, I put in 12 feeder gold fish. <Not a good idea... real trouble as a source/vector for disease...> If he has eaten any of them it was only one, as I now count 11. But I don't know if that was done here or at the store. The water was cloudy on the first day after the change so I added some Stress coat to my 50 gal tank. The water cleared up beautifully. Now I want to give my fish a hug. He seems depressed almost afraid of the gold fish. He has always been "moody" after a water change, but only for a few hours. I changed his water last Tuesday and he has not snapped out of it. He mingles at the bottom of the tank in one corner or another. He still comes up to see me for feeding, but he is not nearly as perky and playful as usual. After eating about 5 pellets he meanders back to the bottom. He is not playing with the goldfish at all... the goldfish are not even afraid to go eat his pellets in front of him!! It is almost as though the goldfish are bullying my Oscar!! <Happens> I see suggestions of Epsom salt, live worms, and water testing. I have never done any of those things. Where should I start??? <Reading further> I do not see any visible fungus, or sickness. His eyes and fins look good at this point, although the water seems to be getting a little cloudy again. By the look of the water, it seems like maybe his natural slime is falling off?? <Possibly... the water change, possible disease from the goldfish...> He still comes up and "kisses" at me and my children when he is visited. He just seems sad and sluggish. I want to catch whatever it is before it becomes a bigger problem. Please advise on where I should start to diagnose our pet. Thank you so very much for your time and your website. I look forward to hearing from you. Jessica <Mmm, keep reading, on WWM re feeder goldfish, all the Oscar FAQs. Bob Fenner> Re: Oscar Looks Like a Red Devil, Chuck's input Hello there, and thank you so much for your prompt response. My gut feeling is to remove these goldfish, of which I will do today. I have since been to the library and have found that I don't have an Oscar, but a Cichlasoma citrinellum (Midas Cichlid). < Go to fishbase.org and search for red devil. There are a couple of fish that look similar.> I have also learned he is indeed a male. :o) He is a beautiful fish and I plan to search your website for info on him. Do you have any tips on this type of fish?? < You seem to have learned a lot and I think you are already on the right track.> He seems to have a lot of the same characteristics of the Oscar is there any definite differences? <The are both new world cichlids. The Oscar comes from South America and the Red Devil type comes from Central America. They are both one of the top predators in their natural habitat.> I also purchased a heater, and thermometer for his tank, he has never had one before, but I want him to be comfortable. Dang, I forgot that water tester equipment that you advised! Back to the pet store. Thanks again for your advise and your website. I appreciate your time and your help. Jessica < This is what Wetwebmedia is here for.-Chuck>

How Many Oscars? Hi, I have a three foot long tank and wanted to keep two pairs of Oscar. Is it ok to keep 2 pairs? < NO!!!!! Each pair of Oscars should have at least a 50 to 75 gallon tank to themselves.> Is it true that they fight in small numbers and are better in large number ? <When fish are kept crowded a aggressive fish will have more fish to pick on a the aggression is diluted. If there is just on other fish then it is picked on all the time and soon will be dead.> How many Oscars do you suggest? < Only one.-Chuck>

Abused Oscar - Ungrateful Owner Ok I am aware of how fast Oscars grow, and I did do my research. I have had a personal conversation with David Burochowitz, editor of Tropical Hobbyist Magazine, and he assured me that with adequate filtration and a weekly 50% water change, which I do, that it would be fine. Sorry I asked you for advice, but I trust his experience to yours. Thanks for spending about ten words on my real query about his shyness and the appropriateness of the rocks by saying that they don't matter, that's really helpful. You know, some people get so anal about things that they consider themselves "experts" on, it really irritates me that you were so focused on being right about something that you completely ignored my issue. At least you did give me a little info, I know to take my questions elsewhere. >>>I'm sorry, I didn't realize you had a conversation with an editor. If I had known this, I wouldn't have attempted to educate you on the appropriate size tank for this cichlid. You see, we all know that if an editor says it, it must be true. They edit after all. I don't know much really anyway, I've only been keeping and breeding Oscars and other New World and African cichlids for 20 years, so I'm a bit of a noob you understand. I haven't edited a magazine, so you should probably ignore my husbandry advice. If the editor of Dog World told you that keeping a German Shepherd in refrigerator box was acceptable, I suppose you'd believe it as well? So be it, don't let the door hit you in the... as they say... Jim<<<<

Another Cramped Oscar.... I have an Oscar that is about 3 inches long. I got him about 2 months ago and for about a month and a half he was the sole occupant of a 10 gallon tank. Now before you jump all over me, I know it was too small of a tank for a grown Oscar, but it was a complicated situation and I had no choice but to keep him there while I saved up to get him in his current tank, which is 33 gallons. He wasn't very shy in his old home, but he's been in his new tank for a few days now and he always hides behind a piece of fake driftwood when anyone walks by. He will eat, mostly pellets and occasional earthworm, but he waits for me to back away from the tank where he can't see me. I don't think the tank is cycled yet, but I'm keeping a watch on ammonia levels and they seem to be safe (the tester I have doesn't show ppm, it just has four colors: safe, alert, danger, and toxic). I was able to jump start the cycling process with bacteria from another source so I suppose the tank could be cycled already but it's unlikely. Anyways, I figured maybe he was being shy due to the lack of hiding spaces in his new and much larger tank, so I went to a creek near my house and found him a few rocks (they appear to be a red shale, but I'm no rock expert so I can't be sure.) I did a little test on them by pouring some vinegar on them and watching for bubbles and saw none, so I boiled the rocks for a bit, scrubbed them off in clean water, and put them in his tank. He hasn't explored them yet and he still hides in the same spot, but the rocks don't seem to be having any adverse affects on him. Just in case you need to know my regimen, I do weekly water changes of 50% and right now until I'm sure the tank is cycled I'm doing daily water changes of about 10% even though the ammonia tester I've got says nil ammonia. Is there anything I can do short of getting him a larger tank that will make him happy, or have I scared him for life by changing tanks on him after he got used to the old one? >>>Heh Travis, How much research did you do before purchasing your fish? You ARE aware that 33 gallons is just as laughable long term as an Oscar tank yes? These fish grow VERY large, VERY fast! How fast? Well they put on about an inch a every week and a half to two weeks until they reach about 10". After that they grow a bit slower, and females may stop there for a while. Males will keep right on truckin to 11"-14" depending on genetics and surroundings, also a bit on maintenance and nitrogen cycle management. At any rate, all the stuff about your rocks and shyness is of no import really unless you plan to get your fish AT LEAST a 55 gallon tank rather soon. If not, take him back and purchase a smaller species of fish that will live happily long term in a 33 gallon tank. You have maybe another 2 months with your Oscar in this tank. There are MANY other options to choose from, including some VERY nice medium sized Central and South American Cichlids. How about a nice Firemouth? Be aware that Oscars are VERY messy cichlids, and you will need to do 30% water changes weekly to keep his parameters in line. Otherwise you risk a variety of problems, including "hole in the head" disease. Good luck Jim<<<

Oscars or Sardines? Hey there, We just purchased a 28 gallon tank last Tuesday. We have a small filter that I believe the sales guy gave to us accidentally. After waiting almost a week, we bought our three red tiger Oscar fish. (tonight) One is doing really well eating and swimming around. The other two have been on the gravel since we got them. They are laying on their side and gasping for air. What do we do?? separate them immediately or is this stress from ride home? Or something we did wrong?? Thank you if you have any solutions. Bri >>>Hello Bri, Did you do any research on these fish before you purchased them? This 28 gallon tank is a quarantine tank I hope, before you transfer these fish into a 150 gallon correct? Oscars grow at a TREMENDOUS rate, (literally) over an inch a week <month, RMF>, to an inch every two weeks until they reach 10" or so. At this point growth slows down somewhat, but continues until males reach a length of 13" or so. Females often stop at around 10". Your tank is MUCH too small to accommodate even ONE of these fish for more than 6 weeks or so. In answer to your question, assuming your water parameters are in line (which I can't tell from here) then what you are seeing is a stress response - Oscars do this. However, if this tank is intended to be a home for more than a few weeks, you need to take all of these fish back and consider a MUCH smaller species. Also, not sure how your "accidental filter" fits into your query. Good luck Jim<<<

Oscar confusion Hello guys! Long time no posting on my part. I've been reading most of the FAQs on the Oscars and am confused. I've been getting mixed signals about tank size the more I read. I have a 58 gallon Oceanic tank at my disposal and am debating with myself about what to do with it. I have an African cichlid tank at my house with a Cobalt Blue ___________ (I admit ignorance to his real name. I want to say Hap but I am unsure. < It used to be Pseudotropheus and is now metraclima.> The pet store in my area isn't the greatest.), so I'm pretty sure I want to move away from the African varieties (unless I can get a Frontosa in the mix). I love Oscars and they are my number one pick right now, however I'm confused as to whether or not this tank is big enough. I would have lots of rock work and I wanted to try live plants but it sounds like the live plants aren't such a good idea. < The Oscar would work with proper filtration and regular maintenance. The plants would soon be uprooted and eaten> I was also hoping to get some Tiger Barbs or Tinfoil Barbs in the tank too, < Tiger barbs get about three inches and are attractive and active. The tinfoil barbs get up to a foot long and really require large tanks because they prefer to swim in schools and need lots of room to swim.> just something for visual variety. If the Oscar idea won't work please tell me something that will that doesn't include a boring community setup with gouramis or angel fish (no offense to the community setups out there). I really want some big fish that are just (for lack of a better word) cool. Please reply to XXXX@hotmail.com Thanks for you help and I hope you have happy holidays. < Lots of suggestions here. You could try a Lake Tanganyika community tank. Lots of color and activity. Make a couple areas with rock piles and open sandy areas in between. Add one lamp sp. like Leleupi, daffodil, brichardi, compressiceps or calvus. Then you could add a Julidochromis species like ornatus, regani or transcriptus. In the sandy areas you could use a sand sifter species such as xenotilapia or callachromis. In the open water column a large school of cyprchromis sp. would look great. Add some shells and get some shell dwelling cichlids. Another way to go would be will small central American cichlids. Convicts , firemouths, and other s make an interesting interactive tank. Just make sure that they have lots of rocks and things for territories. For more info on getting and learning about cichlids check out the American Cichlid Association at WWW.Cichlid.org.-Chuck> Ty

Oscar and Gar in a 55g? I was recently at a pet store and I was told that it will be ok for me to get 2 Oscars and 1 gar fish and put them in a 55 gal tank. I want to know will they get along and will 55 gal be enough. If not what should I do? >>Hello :D Since you are asking, I get the feeling that you think a 55g would NOT be large enough, and you would be right. A 55g is not even large enough to house ONE Oscar for it's natural lifespan, two would require twice-weekly water changes just to keep them healthy, no guarantees either. Adding a gar to the mix would be a bad idea, and I am sure that someone down the line would talk you into adding a Pleco as a cleanup crew...another bad idea! The average Pleco sold to you would probably be an Hypostomus species, growing to two feet and not an ideal cleaner-upper, they create more waste than they remove. If your tank is a 55g, I would recommend going with some smaller species of Cichlidae, perhaps some jewels, some keyholes, some convicts if you like protective parents ;) or maybe just some Gouramis, or a nice community tank. A 55g is too small to house most cichlids for any length of time. If your pH is high, say around 7.8 and higher, you could house some Africans in there, but beware of aggression, even though the Africans may not grow to 15 inches, they are aggressive enough to warrant a great deal more space. Good Luck :) -Gwen<<

Re: Oscar in 55 gal tank Thank you for responding so promptly to my last email titled "Cichlid water qualities+well being" I took your advice and moved my tiger Oscar into the 55 gal tank. The only problem is that I heard you couldn't put plants in with Oscars b/c they like to dig and will uproot them. <Correct> So now the tank looks so bleak and bare. All I have in it is a few medium-small sized rocks, a larger rock, and a small piece of low lying fake wood with some river stones scattered around it. I also have white gravel in the tank. Should I change the gravel to brown/natural? < Gravel is just a matter of personal taste. Brown would probably make your Oscar look less washed out.> If so could I just add some brown/natural rocks on top of the white rocks or would I need to totally change them? < You could always take a small portion of each and mix them together and see how you like it. It would be difficult to keep them separate since the Oscar will mix them out as he digs through the gravel.> Also, do you have any suggestions as to what I could do with my tank or put in my tank to make it look less bare and more like an interesting habitat that my Oscar would be happy to live in? <Look for large pieces of driftwood to add to your tank. The seasoned wood adds some tannins to the water and give it a tea colored look. In nature Oscars would hide near fallen tree stumps and near the roots of trees along the waters edge. Stores sell this material as "African Ironwood". It is pretty much already seasoned and will not float. You could always make your own by obtaining some would near a creek, stream or river and soaking it for a few weeks or months until it sinks.> Also, I got this tank used form my grandfather about a year ago, but I still have no idea as to how powerful the filter is. All I know is that is fairly large, and it consists of 2 separate but connected parts, the filter and the BioWheel. I also know that it is a hot magnum filter. Do you know of any way to see what power it is without having the box handy? < The Marineland HOT magnum pumps about 250 gallons per hour when the water flow is unobstructed. This will give you a 4 to 5 times per hour turnover in your tank. The BioWheel is an excellent attachment to the system. The bacteria live on the wheel and break down the waste products down into less toxic nitrates. The magnum does not have a high capacity for storing waste and will clog soon after cleaning up a messy fish such as your Oscar, so watch the water flow and when it slows down you will need to wash it out. Rinse the wheel every once in awhile under a gentle garden hose to remove excess build up. Take the magnum apart and make sure you rinse the filter fabric under a strong stream of water to clean it. Add or replace the carbon often in the filter basket to keep the water sparkling clear.> I am also going to put my African cichlids in the 29 gal now. That would work out fine wouldn't it? It said that these cichlids only get up to 5 inches so they would be ok right? Would I be ok to add 1 or 2 more also? I have 3 now, and they are about 1-2.5 inches long. < African cichlids actually do better when they are crowded together. I would put in somewhere between six and ten fish. You are adding a lot of active fish to a not so big tank so you will have to have a good filter, feed only algae flakes and check on the nitrates to decide when water changes need to be done. Check out the local fish store for a book on Malawi cichlids. You may be surprised on what species are available. Stay away from some of the larger ones (Up to 12 inches). They too can get as big as your Oscar and then you will be in the same situation all over again!!!-Chuck Cobb

Re: Cichlid water qualities+well being How are you? < Fine thanks> I would greatly appreciate it if you could help guide me in the right direction with how to maintain my cichlids. In the past I had 3 Oscars. I have lost 2 to various diseases such as hole in the head and body rot. I don't want this to happen to my last Oscar. He is 1 year old and around 6-7 inches long. He is currently in a 20 gal but I am thinking about moving him to a 29 gal. <Oscars are from South America and can easily get up to one foot long I would recommend at least a 55 gallon tank for your one remaining Oscar>> I know that the filter is too small for the tank right now but I will change all of this with the 29 gal. < A 29 gallon is better but still not good enough. If a 29 gallon is all you have right now I would recommend a large outside power filter that pumps at least 100 gallons an hour and is easy to clean> The remaining Oscar is a tiger Oscar and he is in the tank with a Pleco. He has a small amount of hole in the head I think... and I am not quite sure how to maintain his tank or how to keep him perfectly healthy. What does his ph need to be? I have heard that it needs to be around 8.2, but he is currently at about 7.5. Is this ok? is it possible that he has adjusted to this ph and doesn't need to be in 8.2? also, I think that my tap water has a ph of about 7.0 or lower, and I hate to have to go through the process of raising it every time I change the water. < Don't worry about the pH right now. Get a nitrate test kit. I think you will find the nitrates are off the scale. Reduce the nitrates by doing a water change and servicing the filter. The nitrates should be 25 ppm or lower. No more than 50 ppm or you will start having the problems you describe all over again> I have been feeding him cichlid pellets, any other diet suggestions? < Oscars eat just about anything. Try some washed earthworms every once in awhile> I recently bought a huge container of Jumbo Min for my Oscar, but when he eats it he flushes more than half (or maybe all of it seems!) out through his gills. Is this normal, and should I keep feeding him this seeing as he is making a huge mess out of it? < Oscars are messy feeders. As they chew their food some of it ends up flowing through their gills. This is normal for them.> Also, how am I supposed to measure his ph if the test kit only goes up to 7.6?? < They make high range pH kits, you may have to shop around.> I currently don't have an ammonia or nitrite/ nitrate test kit, but along with the other aquarium I have, and getting a bigger tank, this is getting expensive. < Initial setup can be expensive but it does not have to be. Spend your money wisely on good quality equipment right from the start and you will have years of success with your aquariums. If your heart is set on Oscars then you need to take care of him the right way. If you cannot give him the care he needs then he is better off back at the pet shop and maybe you should get some smaller fish. > I have been reading on your site and have heard a lot about Epsom, is this a good method to get him in top condition and get rid of the possible hole in the head, or do I just need to get the water stabilized?? < Forget the salts for now. Clean the filter and do a water change. Feed the Oscar only enough food that he will consume in a couple of minutes.> Between him and the Pleco they produce huge amounts of waste, what size filter would be best for a 29 gal? Is there anything else you could think of to make sure my Oscar is in prime condition? < Put him in the 55 gallon tank and take a look at the emperor filters by Marineland. They move lots of water and are easy to service. The bigger the better. Get a gravel vacuum and vacuum the excess food out of the gravel when you do your water change. You will have less algae and your Oscar will be very happy. > Sorry for such a long email but I also have questions about my other tank. It is a 55 gal, and I have currently purchased 3 small African cichlids and plan to buy more for it, the tank also has a large Pleco in it. Would it be better for me to put the Oscar in the 55 gal, or will he be fine in the 29?, < If you want to keep the Oscar then move him to the 55 or get rid of him> as I have heard that he will be limited in his size by the size of his aquarium...? < His growth and well being will be limited to the amount of wastes built up in the aquarium not by the size of the tank. You have been getting some bad advice, I am guessing it is from the store that may have sold you the three Oscars and a 20 gallon tank.> Back to the African cichlids, will it be ok to introduce more African cichlids their size into the tank, as I have just purchased them within the week? < Most "African cichlids" come from Lake Malawi in Africa and are farm bred in Florida. The usual ones are the fish that eat the algae off the rocks and are called Mbuna by the natives and by cichlid enthusiasts. They are very territorial and will defend their area using those same teeth they use to clean algae off the rocks on each other. When adding fish I would take all the rocks out. Do a water change. Put the rocks back in a different arrangement. Put the new fish in and turn off the lights for the night. This will give the new fish a chance to find their own territory.> Also, what would a stable ph level be for them, or is ph not even as crucial as I think?? < They definitely like the pH above 7.0, 8.0 would be better.> How often do water changes need to be made in these tanks? <Check the nitrates with a kit and keep them below 25 ppm. The amount of water you change and how often depend on many variables. If the nitrates are at 50 ppm then I would consider a 50 % water change over a few days. If they come back in a week then you would have to do a 50% water change every week in your tank. If the nitrates were at 30 ppm then you would only need to a 25% water change or so every week. If the nitrates were only at 10 % then you could skip a water change if you wanted to.> It is a big hassle and seems to put a lot of stress on my Oscar. < In a 29 gallon tank a 7 inch fish doesn't have anywhere to hide. The bigger tank will be less stressful if he has a place to hide like a large flowerpot or big piece of plastic pipe from the hardware store.-Chuck> Thank you for your time. Cobb

Oscars I have a Q, I hope you can help me with. I did read about what I'm going to ask but this is a little different. I have two Oscars one is a male and one is a female the male I sent full grown yet and my female seams to be a lot smaller I was wondering if I could put them in a 55 gal tank I know you should put them in a bigger tank but since I don't think my female Oscar is not going to get so big I was wondering if that would be ok to do. < A 55 gallon tank would be fine for awhile. Make sure you have a filter that pump/filters at least 3 times the volume of the tank and check your nitrates. When the nitrates get between 25 and 50 ppm you will need to do a water change and service your filter to reduce them. How much water and how often will need to be determined by you and your test results. -Chuck> Thank you April

Oscar tank question I have just bought 2 baby 2-3 inch tiger or red Oscars. there like super friend they wont leave each others side. I have a 40 gallon that wide deep and sort of long. I have 2 bio wheels that pump out 150 gallons each. I want to know if my tank will be good enough for them. I really need to know I need to get a bigger tank or replace my filter or any sort of that I'm kind of used to my 5 gallon with tiger barbs thank you this is very important Sean =P < Your forty gallon will do for awhile. Your filtration is very good. Marineland makes excellent products. When you Oscars get about 5 to 6 inches long I would start thinking about a larger tank. 55 gallon minimum and up to a 100 gallon would be fine. When you switch over then one of your filters could be boosted up to an Emperor that filters 400 gallons an hour.-Chuck>

Pool Filter Sand in Oscar Tank I am setting up a new Oscar tank and seen pictures of a guy who used pool filter sand in his and I really like the looks of it. My question is, is it O. K. to use this type of sand in an Oscar tank or will it create me problems down the road due to the silicates it contains? <Sand is basically silicon dioxide SiO2(Quartz and glass). As long as it is well washed so no dust sized particles are being returned to the tank you should be OK. Some problems may arise using sand blasting sand. Sand blasting sand is crushed sand that is angular and abrasive. It can also be abrasive against a fishes scales or eyes should they rub themselves on the sand . This is especially bad for Lake Tanganyikan sand sifters.-Chuck> Thanks for your help, Bryant Brown

Minimum tank size for two adult Oscars Hi. I was wanting to know what is the minimum tank size for two adult Oscars. < Probably at least 100 gallons with good filtration. Adult Oscars are big fish and messy eaters, so you need a good filter that is easy to service and will do the job. I would recommend the Marineland Tidepool filter with the skimmer attachment. Look around and you can probably get both for around $200. You will still need to get a pump for it. You need to get a pump that will pump at least 300 gallons an hour. The Tidepool system can handle up to 600-700 gallons per hour. The best thing about this filter is it has a very large biological filter with its built-in BioWheel. It is very easy to service. Check it out.-Chuck> Or what is the best for them. Thanks.

Tiger Oscar Hey, I was just wondering when I should clean my tank. Its 10 gallon with about a 3.5 Inch Oscar. I know the tank is small but its okay for know, I'm eventually going to move him over to a 55 gallon once he is larger. The filter is Regent it came with the aquarium. It also has a small log in it with a heater and a thermometer. I feed him 3 pellets, 3 times a days. I'm wondering how and when I should clean my tank and change the filter and also vacuum the stones and change the water and how much percent of the water. Thanks < You need to have your water tested. You should have no ammonia and no nitrites in your water. If you do you need to service the filter and vacuum the gravel. The nitrates should be no more than 25 ppm. If they are higher then you need to do a water change to bring them down to that level. As a general rule I change 30 % of my water every 2 weeks while vacuuming the gravel. On week that I don't do a water change I change the filter. Check out Dr. Tim Hovanec's articles on filtration at Marineland.com and then click on Dr. Tim's Library for a more in depth understanding.-Chuck> Also I just became curious about my Oscars back fins, the tips are clear but just barely the tip (about 1mm-2mm ). I did some research and it sort of looks like Fin Rot but I'm not actually sure because I can't remember if he always had that as if it was part of his colour scheme. Sorry for the questions in the same day =-} < It could be part of the color scheme. Watch it closely to see if it grows.-Chuck>
Re: Tiger Oscar Again
As you know my Oscar is about 3 inches long, he's the only one in the tank and the size of it is 10 gallons it also has some decoration stuff in it like a log which is 5 inches long 4 high and 2 wide and an other decoration which is 1 inch wide 1 long and 6-7 high. it also has a heater 1 filter and a thermometer. I'm going to move him into a larger one ( 55 gallon ) once he is bigger. I was wondering how many times should I clean the tank and change the water est. ( keeping in mind that he is the only one in the tank). Thanks again < It depends on how often you feed, how much you feed, and what you feed. Start out changing two gallons a week. More if the water starts to smell or looks cloudy. This will keep the wastes down and your Oscar will grow quickly. -Chuck>

Just bought 3 Oscars Hello, I just bought 3 medium size Oscars from PetSmart last night. They told me that they would be OK in my 46 gallon tank.... even if they get to be 12 inches long a piece.... After reading a bit on your website... it sounds like they were wrong!! What should I do? Can I make it work? They are doing very well right now. < Check the nitrates. They should not exceed 25 ppm. If they do then you need to change some water to get them down. I think you will find that you will need to change water at least a few times a week with this many large Oscars in this tank. They will eventually get sick and not look very good or you will get tired of changing 25 gallons of water every other day. Start thinking about a larger tank in the next few months.-Chuck> Please help! Kathy Houston, TX.
Re: Just bought 3 Oscars
I checked my Nitrates and it is about 10ppm. How big of a tank will I need for my 3 Oscars? It makes me so mad that they told me they would be OK in this tank.... they were using the method... 1in. of fish for every gallon..... I might see if they will let me return them.... I am afraid that I won't be able to get a larger tank... they are so expensive! I hate to return them.... I have wanted cichlids for a long time!! and when I saw the Oscars I thought they were so neat. If you have any other words of wisdom, please let me know! Thanks for your help!! < Keep in mind that healthy Oscars will be close to a foot long in a year or so. Your 46 gallon tank is probably a little over 3 feet long so it won't take too long before there is no room for them to swim. You can keep smaller cichlids that are just as interesting and colorful and don't get too big. I would recommend central American cichlids of the genus Archocentrus. Males get about four inches and females get about half that. They are a little aggressive but are easy to keep and breed. A. nanoluteus and A. myrnae are a couple that would very easy to keep and are very pretty too. They are not too common in pet shops yet so you might have to look around. Check out Aquabid.com there may be some on there you can bid on. -Chuck> Kathy

Night Fright Hello WWM! <Hello back. Don here> I have a problem with my 2 red Oscars and my sailfin Pleco. I have a fluorescent light and when ever I turn it on the fish go to "their" corner and sit on the ground hardly moving except when spooked by the other fish. Another problem I have is at night when I'm asleep I hear a big splash and gravel hitting the glass. It makes me jump and scares me. The fish have scars on there head from this in the past and I am afraid its not the heater or electric. It's like the fish spook each other. pH, nitrites, nitrates, and temp. are all stable. <What are the readings? Ammonia and nitrite must be at zero. Nitrate below 20ppm. Water conditions could be a reason for the inactivity of your fish. You should be changing lots of water with these 3 fish. Up to 100% per week in 2 or 3 stages. Depends on the size of these fish.> The temp stays at 78. They're in a 55 gallon aquarium. <OK if the fish are small. But these are three large fish as adults. The Oscars can hit a foot, the sailfin Pleco can reach 18 inches! All are messy eaters and produce a ton of waste. Make sure you vacuum your gravel> <First, the splashing you here at night is either from your sailfin, or the Oscars being scared by the sailfin. Plecos are more active at night. He's just out looking for food and waking up the sleeping Oscars. It is not uncommon for a large, starving Pleco to try and take a bite from a sleeping fish. Try giving him a piece of zucchini, squash, cucumber or carrot. Attach it to a rock to keep it at the bottom and add just before you go to sleep. That may calm things down. About them being shy/hiding; Any chance another pet is bothering them. Maybe a cat? They may feel unsafe with the lights on. A cat may even explain the night fright. Make sure there are plenty of places for them to hide. They will come out more if they know they have a safe home to retreat to when scared.> I also have another problem. I have 4 cichlids, one electric yellow <nice, but can be aggressive> and 3 I don't have a clues <Also nice. I use to breed "Idonthaveaclues". Won a prize for my Idonthaveaclue whatelseisnew :)>, my friend gave me the tank. Its not good at all. It's a 10 gallon. The filtration is perfect <What is it?> but the space is cramped. <Agreed> The electric yellow is 3 inches while the others are abut 1 inch. The 3 unknown species (with vertical stripes. They are blue in color and the other one dark with a red fins. Not a red tailed shark I'm 100% sure on that. Doesn't even look like it) but anyways, the electric yellow seem to torment the smaller fish. <Yep> I'm going to return the 2 Oscars and move them into there, but I'm afraid of the Oscar problem happening to them. Please help. <Before you choose which fish to return, check your pH and hardness. The yellow is an African cichlid and likes a high pH and hard water. The Oscars and Pleco are South American and like a lower pH and softer water. If you match the fish to your local conditions you will have fewer problems. But if you go with the Oscars and Pleco, you will need a larger tank in time. If you put the Africans with the Pleco, he may still cause a commotion at night. Again, target feed your Plecos!>

Night Fright pt 2 I also have something to add to the Oscar problem. It seems that the light stay on thru the week at night Mon-Fri. <Not good> I'm not here on the weekends due to divorce problems. <Sorry to hear. Been there> Is this a problem and do they have timers so the light turn off and on by timer <Yes, or leave them off all day. Better than on all night> and some kind of automatic feeder. I'm trying to move them to the house I'm at Mon-Fri but it's slow happening. Also how can I move my fish long distances about 75 miles doing 60 the whole way.....thanks. <You can get a small timer to handle the lights. Any hardware or department store will have them for less than $10. You can also get auto feeders at some of the larger pet stores or online. Better if you can talk whoever is there during the week into feeding them. As to moving them, it really depends on the size of the fish. Small fish in a large plastic bag half filled will be OK for an hour or so. If they look like they are gasping for air, open the bag and splash the water around a little. Larger fish can go in a clean bucket or other container. A battery powered air pump with an air stone will help a lot. Take as much of the old water as you can, use it to refill the tank. If your filter has a bio wheel or pad, keep it in tank water and reinstall on the tank. Do not clean it or keep it in tap water.>

Oscar systems hey there guys, hopefully you can answer a question I have that I hear a different answer for every time I ask! I currently have 3 Oscars (2 tigers, and an albino red) all between 5 1/2 and 7 inches collectively, and a 14 inch common Pleco (no joke, this is the largest Pleco I've seen before) in a 100 gallon tank, with a Fluval 403 canister filter.......is there a problem with this setup? < No the set up is fine.> is my tank too small? < No the tank size is fine too.> will I need more filtration? < That all depends on a couple of factors. Your filter should turn the tank over at least three to five times per hour. How often do you do water changes and how much water to you change. The nitrates should not be over 25 ppm. If they are then you need to change the filter and do a water change to reduce them.> will I eventually need to re-house one of my Oscars? < Don't think so.-Chuck>> your help with this query would be greatly appreciated, as I have the time and money to do what is right for these fish, but I need to know what actually is right first in advance what's best for my Oscars

Tank size Hi guys! I've written before and like you site. I was wondering if a 125 gallon tank is big enough for a pair of Oscars plus a few other tank mates. I have two albino red Oscars that have great color to them. I bought them when they were about 1-2 inches long. They are now about 6 inches and doing fine. I have both of them in the 125 gallon tank with 3 Severum, two Plecos, a blood parrot, a large snakeskin Gourami and a dojo loach. All of them get along fine, the Oscars run into each other sometimes trying to beat each other to food. I've read that it is better to have either just 1 Oscar or several but not just 2 due to the larger one picking on the smaller one. I haven't had any problems, but both of my Oscars are pretty close in size. Do you think this size tank is big enough for them to grow healthy and happy in? Thanks for the advice < The tank size is fine. If your Oscars decide to pair off then all the other fish in the tank will be in trouble. Cichlids guard their eggs and young from all other fish. They may even kill the other fish to protect their young. Something to out for when they get bigger than 8 inches or so.-Chuck> Bill

Wet Web Psychics Could use your helps please guys! <So long as I do not have to leave my house.> Hopefully you can answer a question I have that I hear a different answer for every time I ask! <Damn Magic Eightballs, so wishy washy. Just give me a straight answer, please.> I currently have 3 Oscars (2 tigers, and an albino red) all between 5 1/2 and 7 inches collectively, and a 14 inch common Pleco (no joke, this is the largest Pleco I've seen before) <I know them well.> in a 100 gallon tank, with a Fluval 403 canister filter.......is there a problem with this setup? <Yes> Is my tank too small? <As I see it, Yes.> Will I need more filtration? <Yes Definitely> Will I eventually need to re-house one of my Oscars? <Cannot Predict Now> Your help with this query would be greatly appreciated, as I have the time and money to do what is right for these fish, but I need to know what actually is right first ;) <Better Not Tell You Now. Ok, Ok, sorry, I'm done. Environmental variables will directly affect their growth rates. Diet, water temperature, water quality, tank mates, and on and on, will all play a role in their development. Luckily with a 100gal tank you have some time to plan for their futures (College? Medical School? Maybe even an Astronotus?) It all depends on the quality of life you want for your fish. If you keep them in the 100gal and do everything else perfect, you are going to find yourself with 3-5feet of Oscar that have no room to swim, attitudes to match their size, appetites to match their attitudes, and all that food has to go somewhere. It won't work in the long run (2-5yearish). I give the Fluval a few more months at best. Great filter, but buy itself it cannot keep up with the bioload. I'd add another canister filter for now, and of course weekly to biweekly water changes.> BTW these fish all get along great. <Don't worry, that'll change in time. Consider some drift wood for your tank; the less dominant will use it for cover, and the big boys can push it around without injuring they fleshy faces.> in advance what's best for my Oscars <Frequent water changes and a varied diet.-Gage>

Tank size for Oscars I had a question on how big of a tank I should get for my 4 Oscars (1 lace, 1 tiger, 2 albino red) and still have room for some other fish, and what other fish would be a good choice preferably other cichlids)? Also for this tank what kind of filtration would be needed? < If you intend to grow them to adults then I would recommend a 100 gallon tank with a power filter that pumps at least 400 gallons per hour.-Chuck> Thanks

Huge Oscars Hi Bob I am lost in Oscar land... One of my friends had to leave the country for business and had to leave his Oscars behind. I collected them a few days ago. I was completely caught by surprise. They are huge fish (5 years old). The Oscars had a stressful ride home after which I immediately placed them in a 20 gallon tank (biggest I had). The tank was set up only 2 days before. The male was very stressed at first and stayed on the bottom of the tank. The female seemed fine. The water quality deteriorated so I installed another filter and partially changed the water. The male started eating again the next day, but the female has not eaten at all. (3 day now) This morning I found the female resting at the bottom of the tank. Her stomach is a little swollen and her lips are a faint pink color. One of my friends suggested that I try feeding her live food. What should I feed them? Should I partially change the water again? Should I move them to a bigger tank at this stage? The water is still a bit milky at this stage... This is the first time I try my hand at Oscars so any advice would be much appreciated. < The milky water is ammonia and needs to be removed. Your fish should be in a 55 gallon tank that has a filter that turns the water over at least three times per hour. It will take a month to get the beneficial bacteria going to break down the toxic ammonia down to less toxic nitrites and then even less toxic nitrates. They should be keep at 80 degrees and fed a high quality flake and pellet food. Stay away from live or frozen food until you get them into a larger tank. If you intend to keep them in the smaller tank then you will need to change lots of water every day as well as change the filter almost every day. If you do not do this then they surely will become ill.-Chuck> Regards Jaco

Lazy Oscar/High Nitrates Hello, I just purchased a 1" Tiger Oscar - by recently, I mean yesterday. When I got home, he seemed ill before I even got him out of the bag. He was just resting on the bottom of the bag on his side. When I moved the bag, he would swim around a bit, but then just settle back to the bottom again. Since the store was already closed by then, I let him loose into the tank to see how he fared. He swam about for a minute or two, but then settled down to the bottom again. Every once in a while for the rest of the night, I would take a look over, and he would be in a different spot - but never saw him swimming around. After I turned out the light for the night, I noticed he began swimming around quite a bit. Now this morning, I noticed that as soon as I turned on the light and went to feed him, he stopped swimming and rested down to the bottom again. Whenever I looked over today, he seemed to be on his side on the bottom. But now, from across the room, I see him swimming around rather energetically. But as I just walked over to the tank, he swam to the corner and rested on the bottom. However, there are no visual symptoms of any illnesses, that I can see. The only water condition that I am adjusting is the nitrates - any suggestions as to how to lower that? The only thing I've found so far is to do water changes, but that hasn't been successful in any of my tanks so far. So, basically, what I'm asking is do you think he could be lazy, or just nervous around me and his new surroundings? Or could there be something actually wrong with him? Thanks, Brian <Hi Brian, Don here. I think he may have been in the bag a little too long. That, combined with the stress of a new home. Don't feed him for a day or two. He won't eat anyway. Let him get good and hungry. Do a few extra water changes. He should recover and start to hunt around the tank in a few days. Don't feed until then. If there are other fish in the tank, they'll be fine. Watch for aggression though. Hope this is a big tank. As to the nitrate question. Nitrate is the end result of the ammonia cycle. It will always raise in a well established aquarium. In a cichlid tank there is nothing you can do except large and frequent water changes. With smaller fish plants would help. Make sure you use a gravel vac when removing water. The fish waste and uneaten food will add to the nitrates faster than your Oscar! Move rocks, driftwood and clean up under them. Then limit the number of fish per tank and feed lightly. Adjust your water change schedule to keep nitrates under 20ppm. If you're doing more than two a week, you have too many fish. Unless your source water has nitrate <US Federal Standard is under 5ppm for drinking water> the only way it enters your tank is in the fish's food. Eaten or not it ends up as nitrate and MUST be removed with water changes. Getting the waste out before it decays is very important to nitrate control>

Overcrowded Oscars I have a 10 gallon tank with 1 sucker fish and 3 other fish. The other fish are small (1-2 inch) Oscar fish. <Whoa! Way too many fish for this tank! A full grown Oscar can reach nearly 18 inches long so even one Oscar is way too much for a 10 gallon tank. These 4 fish should be kept in no smaller than a 75 gallon aquarium, 100 gallon would be better.> I'm having a problem however with the tank. The water stays clear for only about a day and then no matter what I do, unless I do a full water change it stays cloudy. The pH is 7.0, I've added "algae fix" to help keep the algae in control. I've tried "tetra aqua-easy balance" to try to get rid of the cloudiness, as well as "clear water" which is supposed to remove cloudiness. Nothing is working. It's getting frustrating because the tank just isn't as pretty when it's cloudy. <This is all probably a result of the tank being overcrowded. The water quality is probably very poor because of the feeding necessary and the wastes from the fish. Algae is not causing the cloudy water here, its probably ammonia.> Is there something I'm missing? Something else I should be testing, like ammonia and nitrate levels? If so what should the level for my fish be? <Ammonia and nitrites should be at 0 in any aquarium. You need to either get a much bigger tank for your fish or get rid of the Oscars and get some fish that stay small for your current tank. Be sure to do lots of research on the fish you plan to keep *before* you buy them. Theres a ton of info available on http://www.wetwebmedia.com and also at http://www.fishbase.org > Thanks...Kendall <You're welcome! Ronni>

FW Filtration Howdy, I found your site and read for a few hours yesterday learning a TON of information regarding my new 30 gallon freshwater tank. <Glad we have found each other> The basic setup that I have is a 30 gallon Power Filter, 100 watt heater, thermometer, ammonia chart (which changes color in the presence of ammonia), 2 plastic plants, and one large plastic magma/lava rock formation. I have (2) small 3 inch Tiger Oscars, and one 4 inch blue channel catfish. When I first got my tank I had read differing ways of cycling the tank for the first time and the leading websites, not yours, recommended just starting the tank with 2 to 3 small, hardy fish. <Yes> Let me start by what I did wrong: WAY overfed them, tried a bunch of different chemicals (store-bought) to deal with the ammonia problem. This led to ICK which I am now treating with CURE-ICK. <Yikes! Quite an adventure> Today I literally cleaned my whole tank with a light bleach solution and a 100% water change. I know this will now need to start the new cycle again and is but a temporary solution but I wanted to get all of the scuz out of my tank and start fresh �� and hopefully a little wiser. <Much better> The questions that I have are as follows: How often should my fish be fed on a normal basis? Every day or every other? This is what my LFS recommended because of my ammonia problem. <Twice a day for most aquarium fishes that might go in a thirty gallon system... some need to be target fed (like sinking pellets for bottom dwellers)... If you suspect ammonia et al. nitrogenous wastes might be a problem you're encouraged to get and use test kits... not to feed at all if the ammonia, nitrite approach 1.0 ppm.> How MUCH should I feed my fish? A friend claims the stomach is about the size of the eye. <Better to use time as a guide here. Tap some food into the top of the can it comes in for gauging about how much you're applying... and see if they eat this much in a couple, three minutes... there should be no food laying about> What other type of filtration would you recommend besides the Power filter that I have? Please try to give me the best solution under $200. <Perhaps adding an airstone, pump for same, tubing, a check-valve... the present power filter is fine otherwise> Erm, anything else that you can help me with would awesome and thanks again! Awesome website!!! Jim Howrie <Looking forward to your future participation. Bob Fenner>
FW Filtration
Thanks for the speedy reply! I do have an air pump, tubing, and one of those fibrous release tubes. I have the air pump set to max for the most aeration possible but do not use an air stop or check valve. <Do get one or at least "loop" your tubing above the aquarium height... to discount the possibility of back-siphoning (started by capillation) in the event of power or pump failure> My main concern is that the filter will not really allow enough of a medium for "good" bacteria to set up on. Another problem is feeding. These Oscars will eat and eat damn near non-stop if I feed them. I was target feeding the catfish. I would drop about 3-4 shrimp pellets into the corner where he hangs out just after I turn out the light at night. <Good technique> How long should the light be on for a day? Should I get on of those little timers to regulate the light? <A good idea. If no plants, about any length, regimen you like... perhaps ten, twelve hours a day> And I know that you are an expert and all, but are you sure there isn't a better way for me to filter? Such as getting a biological filter or a combo or something? <Mmm, more filtration would be better, will be absolutely necessary with your fishes growth... you could add another outside power filter (hang on or canister type)...> I will eventually get a larger set up when the Oscars get larger so anything that you recommend now should and will be used for the larger tank anyway so it would not be a waste of money. From what I have read on your website too much filtration is never a problem. <This is correct> So what type of filter system would you recommend for a freshwater say 55 gallon tank? <For Oscars et al., vigorous outside power filtration, powerheads in the tank to add circulation, aeration... and frequent partial water changes... likely ten, twenty percent a week, with gravel vacuuming.> Thanks again!!! Jim Howrie <You're welcome. Bob Fenner>

Milky water (Oscars... FW...) Hi Rochell and Chris>> Hi I have a 66 gallon with a Fluval 404 2 heaters 2 aerators 3 Oscars 1 convict its been set up for 2 months and I cant get rid of the milky white water iv tried weekly water changes and it just wont go away if you have any ideas I would appreciate it thank you <<We're going to need more information. What are your water parameters? Do you have the necessary test kits? If not, run a sample of your *source* water and your *tank* water to a local fish store you trust and have them test your water for you, or, invest in some good quality tests for pH, ammonia, nitrite, nitrate, and hardness. I don't know how big the Oscars are, but unless they are small this tank is overloaded, and regardless, will be overloaded in short order by the Oscars, let alone the convict. My bet is on poor water quality with these big eating messy cichlids. Testing will tell you what is going on. You will need to either sell/trade a couple fish, or plan on a bigger tank. Adult Oscars get big. Craig>>

- Filtering Oscars - <Greetings, JasonC here...> I am in the process of purchasing filters for a 125 gallon Oscar tank. I recently ordered an Ocean Clear 340 and a Mag Drive 1200 pump for the tank. I was hoping that I could get an opinion from you people as to if this would be a good and efficient filtration method for keeping these fish in this size tank. <It's about as efficient as 'you' care to be. Due to the nature of these filters, which is really a high flow canister filter, it will be up to you to change the media regularly. If you don't, it won't be efficient at all. Other than that, it's a fine filter and probably what you need for a tank of this type.> Thank you for your help. Brian T. Peek <Cheers, J -- >

What size tank do I need? Hi, last year I bought a 44 gallon tank, 2 red bellied Pacu, and 2 Oscars (1 tiger and 1 red) all from PetSmart. I was told that they could live happily together in that tank, but now they are all huge and seem very sad about their small living area! One Pacu is 12 inches, the other is 10, my red Oscar is 6 inches, and my tiger Oscar is 9 inches. I buy all of my supplies at PetSmart, but no longer trust the advice given by the employees there! Could you please send me an e-mail telling me the appropriate size tank I should buy for my babies?!?! <I hate to be the bearer of bad news but to comfortable hold these 4 fish when they are full grown you are going to need at least a 300-400 gallon tank and even that is going to really be pushing the limits. The Pacus can reach sizes of about 3 1/2 feet long each and the Oscars can reach about 18 inches each. Ronni>

Keeping Oscar cichlids in the tank Alrighty kids, long time listener.....first time caller. I have a question and then a little "story." <I'm all ears> I've had a few different aquariums thru the years and I want to start a new one. My Oscar committed suicide the other evening (hence the "story") but we'll get back to that in a minute. I like the larger fish, so I wanted to put a green Severum, a parrot fish, and an Oscar.....with a Pleco together? <Parrot is the odd fish out> Is this allowed or will they tear each other apart. <Leave out the parrot, and you may keep the piece for a while. You'll need 150 or more gallons to do it, though> Ultimately, I would like to have 3 large fish (could be two of the same fish) and one Pleco living together in perfect harmony (Any thoughts?) <Achievable! It's what we all stride for. A biotopic display is your best chance at peace.> I like fish with character. The four I chose are the ones I like a lot. Once I figure out the fish that can be together, I will get the proper sized tank. Any inkling of info on this matter would be greatly appreciated. <Get them young, hope for the best. Oscars aren't mean spirited, per se, they're just consistently hungry. A pair of Oscars and a large Pleco is going to require a huge commitment on its own...And a killer bioload depending on your filtration> Now onto the story.......My Oscar was about 10" long, so the other day I wake up and come down stairs and what do I see laying on the floor quite a few feet away from my tank!!? That's right, my Oscar. Somehow he knocked the entire hood and light into the aquarium (yea I know, hoods with the light on them are heavy) and then tried to dodge the falling debris and ended up on the floor. <Ouch> Alas, I am saddened.....but what can you do, but to move on and forge ahead.<Too true> Ergo, starting a new bigger and better tank with latches on the hood, lots of latches, latches with chains hooked to them and then wrapped around.......<Ha! Better not let the Oscars see the combination on your Masterlocked tank! These things happen-To our dismay. I think you'd be more successful with a species tank. If you like fish with personality, check out the Tilapia butikoferi. Must be housed alone, but it's a great "Bad boy."> I look forward to hearing from you kids. <And we look forward to hearing back from you! Until next time, Ryan>

Oscars? How do you know all that about Oscars men can you give me some more tips to race some Oscars because I already have three and I want them to grow really good you know and something more can you give me some pictures of the Oscar you have. okay <Oscars are very easy to raise....all you have to do is provide a large aquarium for them (75 gallons to start) feed them sparingly and do small frequent water changes. And choose their tank mates wisely. Whatever you do, don't feed your Oscars feeder goldfish or feeder fish. You would be surprised how many diseases the goldfish can give to your precious Oscar. As for the pictures I suggest you go to www.google.com and do an image search for "Oscars". IanB>

Cramped Oscars <Hello! Ryan with you> I have a 30 gallon freshwater fish tank I have 3 Oscars and 2 Cichlids fish in there. I have fallen in love with a Albino Oscar and would like to know How many more fish I can fit in the tank. Currently my fish get along fine. My tank has been up for 2 months. <1 Oscar will be cramped in your 30 gallon setup when fully grown. You've fallen in love with an animal that's going to require more space, certainly if you'd like to keep more than one. Four Oscars would require 125+ gallons for adequate room for movement. Good luck! Ryan>

Oscar problems I was reading the articles listed. I am having a problem with one of my tigers. First I have them in a 55 gallon tank they are both only about 6 inches each, they were bought at the same time and have been together. <Okay> Recently we had gotten some bad spring water which caused an algae growth. I have been doing tank changes of at least 50% every other day and it is pretty much under control. But now one of my guys is laying around and his sides look as though the other has been pecking at it. I do not know if I have males or females or one of each. I did go to my local pet store to see if they new anything that I could do. They had the usual round of questions did I test the water if they are eating etc. Water is at normal levels <Normal being what? What are your readings for ammonia, nitrite, nitrate, and pH? You mentioned spring water - what are you using for these large water changes?> and no they are not eating for at least 3 days now. <*Neither* of them are eating? I would have suspected aggression above all things, but this does throw in a twist. Most likely this is an environmental issue - with the massive water changes especially; what is your current pH, and has it changed at all since before the water changes? Bottled spring water may very well not always have the same pH, other parameters. Is there any reason you don't use (dechlorinated) tapwater?> Any information you can offer greatly appreciated. Karen <I do hope we can be of service, and help you figure out what's going on.... -Sabrina>

"Oscar in brackish...?!?" (10/28/03) <Hi! Ananda here this afternoon...> Hi, I'm trying to figure out what I might have in my tank. I have a brackish tank, it is kept at about 78-80 degrees. the specific gravity is 1.005, the pH is 7.2-7.4. nitrite, nitrate, and ammonia are all zero, and I do a weekly 25% water change. <So far so good...> About three weeks ago our African cichlid (sorry the exact type was never known) showed signs of fin rot. <Wait. This was in the brackish tank? African cichlids are *not* brackish fish. Also, 7.2-7.4 is far too low a pH for them.> I treated the tank with Maracyn, by the third day the cichlid was moving around again, and the forth even showed signs of re-growth. On the morning of the fifth I found him dead. I continued the treatment until finished. Then did a large water change (half). I waited a little over a week and then got an red Oscar from a reputable fish store. Within about 3-4 hours in my tank the Oscar showed signs of fin rot and body fungus and was dead in under 12 hours. During this whole period I tested the tank frequently and never found a reading off. <Oscars are even less of a brackish fish than African cichlids. They're from South America, where the water is salt-free and on the acidic side of things. I am not surprised you lost the Oscar -- it suffered from osmotic shock in being moved from freshwater to brackish water, and possibly pH shock as well.> The other three fish we have including a bumble bee Oscar show no signs of anything and were perfectly fine throughout the whole ordeal. (also a Columbian shark and a figure 8 puffer) <Hmmm. The bumblebee Oscar will do better in a freshwater tank, too. But do not move him directly from a brackish system to a freshwater system -- that transition should be done slowly. The other two fish should remain in a brackish system.> I trust my fish store and the rest of the Oscars there are all fine. <Yes, as they are in a freshwater system.> What could possibly effect only these fish and happen so fast? <Osmotic shock and pH shock.> I would really like to get another fish, probably an Oscar or cichlid but I'm scared there's still something in my tank. Thanks -Dan <Get another tank before you get another fish -- then move your existing Oscar to the tank, slowly drop the spg. down to 1.0000, and then consider getting another Oscar. Oscars, African cichlids, and brackish fish come from very different water chemistries and should not be kept in the same tank. --Ananda>

I have two Oscars
<Hi there, Just want to start off this email with the note that Oscars get very large, and you will need a large tank to handle both of these fish when they get older. They become aggressive and territorial, not to mention extremely messy. So, please make sure that you have a large enough tank to allow each room. I suggest a single Oscar should be kept in a minimum of a 55 gallon tank. Two Oscars, if they are a mated pair can do well in a 90 gallon breeder tank (larger footprint). If these pair aren't mated then +100 gallon tank is needed.> The other day I came home to find the smaller of the 2 (4 inches) with all of its scales off and in two spots its flesh was exposed
 <Your Oscars are fighting. The larger more dominant one is attacking the smaller one because it's invading it's "territory". This is a sign that you probably have to small of a tank. It's missing scales because the larger one is attacking and ripping them off. This is not good because that means that the fish will have damaged fins and skin and will run the risk of infections.> Now two days later it has this fluffy white substance coming out of the 2 wounds
hoping its not a fungus but I have a feeling it is. <Yes it's fungus. In fact True Fungus which is described as Whitish tufts of cotton-like material on the fin, tail, and body at sites of injury.> Please let me know what the best way to take care of this <separate the fish so that the little Oscar is not being attacked and scales ripped off is the first thing you should do. Set up a medicine tank to handle the fish, and you might want to set up a large one for it to be his permanent home. Once it's in a separate tank I suggest you start medicating him immediately body fungus is dangerous, and can spread quite easily on a stressed and sick fish. Treat with MarOxy (a medicine produced by the Mardel company). Use Maracyn-Two or Maracyn or Tetracycline or TriSulfa to prevent secondary infections.> and also if there is any food that may be more appealing to him (not to interested in eating since the whole thing happened) <That is to be expected, he is being attacked by a dominant fish, his natural reaction is to back down, hide and allow the larger fish to eat. There are many different foods for your Oscar, they aren't picky at all. Not sure what you are feeding, but Hikari makes some rather nice Oscar pellets that most Oscars go crazy for. If not, then you might want to try feeding you Oscar a couple of Crickets (yes the little bugs you get at the store) Oscars diets in the wild are over 60% bugs. Just float them on the surface and the Oscar might be intrigued by the bug to perk him up and then he will start eating again.> Thanks so much!!! Dena <Hope that helps. Good luck with the fish, and look around online there are some great forums totally dealing with Oscars. -Magnus>

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: