my four year old oscar is acting very lazy not eating and at times gasping for air at surface have tested water pH-7.5 ,ammonia-0ppm,nitrite-0ppm,nitrate-40ppm, and GH 12dGH which is a lil' high. It has had HITH,but has almost completly healed and never acted this way.

welcome to the site

without sounding like I'm patronizing you, have you done the test correctly, is the ammonia & nitrite definitely 0?

okay, if the answer is yes, let's look at some of the other factors that could be causing this behavior. What kind of filtration are you using? is the water coming back into the tank causing surface agitation? In other words, is there quite a bit of disturbance and bubbles on the surface of the water? if the answer is no, there is a possibility that there is not enough oxygen in the water, this is why your fish is breathing heavily and hanging at the surface. Have you got any other fish?, how are they behaving? obviously if all fish are behaving the same, it would probably be down to water conditions. if the Oscar is the only fish doing it, I'm afraid it more than likely points to health problems. Could you please get back to us with some anwsers and we can try and help you

I have a freshwater master test kit . just retested ammonia and nitrite both are 0ppm. filtration is 2 aquatech 60s running at full bore all the time .airation is good and also have a 18" wand under gravel.yes another fish ,red oscar both 12-14" in a 55 gal tank Im looking for 90-120 gal tank has been established for 2.5 years fish are 4 years . red oscar is fine.

okay, good on the ammonia and nitrites.how long has the fish been doing it for? Is there any noticeable swelling in the abdomen? and approximately, how often does the fish do it?

I'm afraid I haven't got a miracle cure for you. I've come across this sort of question countless times, search the forum I'm sure you'll find a few cases. Okay, your fish isn't eating? have you tried live food, may be shrimp , worms , live crickets? it's worth a try, sometimes you can induce a fish into feeding by triggering the eating mechanism inside them. Having said that, it really is a long shots and the chances of it working are slim, anything is worth a try.

I should just carry on feeding your other fish monitor the situation. There's not really anything you can do, if the fish is indeed ill, it's difficult to actually distinguish what could be wrong. You could treat the tank with a broadband antibiotic but I very much doubt it would work. I have been in your shoes before, I have had fish that have justed stopped eating,started breathing heavily and then unfortunately......... well, I don't want to worry you unduly. I've even spoken to experts about this very subject, and it's something that baffles even the experts.

sometimes fish come around, keep the water in very good condition, and just keep your fingers crossed. I'm sorry I can't be any more help

Its been maybe 2.5 to 3 weeks for not eating and lazyness only a couple days for gasping at surface and a few times a day sometimes for a few hours . Ive tried hand feeding , and crickets , Ive given them worms before however shortly after I developed a fly, problem not your average house fly ,and the larva live in my filters. could this be part of issue? I usually replace or rinse filters frequintly somewhat keeps flys to a min. ever heard of these flys? so i stopped giving them worms eventhough they love them . should i try worms again?

It certainly sounds like you are really trying with your Oscar that isn't eating. Like I said in my previous e-mail, I think this is in the lap of the gods at the moment. If your water is in good condition, we have to disregard that as being the cause for your Oscars behaviour. If you think about it, if you suddenly become ill, you don't want to eat, animals are exactly the same and this is often a sign that something isn't quite right. Unfortunately, animals can't tell you how they feel. We've all seen vet type programmes, cats and dogs are hard enough to treat, fish at 10 times more difficult. I think it's just a waiting game, your fish may well come round, it may just get worse until there is only one way out of the situation. Please keep us informed on a daily basis, there may be something that happens where we can help.

Re: the flies in your tank, I once read about something called a drain fly, although I don't think this is its actual name. What colour are the flies in your tank? I think these flies feed on the crap that you find in your filtration system. You did say that you clean your filters, if this is the case, you should be able to keep them under control. However, it may be difficult to destroy the eggs. The only way would be to totally dry out the media which you don't want to do. To be quite honest, I've never had this problem so I can't really give you a reliable way of getting rid of them apart from regular tank maintenance. Just be careful that you don't clean your filters too much, you don't want to remove the biological bacteria.