I have an adult oscar in a 20 gallon tank. Now i know that they need to be in a bigger tank but i was given this fish in a 10GAL tank can you beleave that. Iam working on a bigger tank $$$$$$. But he seems to like the one he is in he has a big sucker fish with him but thats it. I have a 40gal filter system on the tank but everytime i change the water which is once a week it always seems to be cloudy after i get it set back up again. Dont know what im doing wrong?? lil help please. than:unsure: ks

If the cloudyness occurs after refilling your tank then your problem might be where you are disturbing the gravel when adding fresh water and throwing up all the rubbish in the gravel into the tank. To solve this problem you will need to do a gravel clean(gravel cleaners can be bought at any fish shop)


Also i suggest you get a water testing kit. Your nitrate levels might be too high. This is possible as your tank is small. One way to combat this until you get a bigger tank is more and bigger water changes

You are already aware that your tank is nowhere big enough for an Oscar let alone having any other fish in there. I would say that your water is cloudy because you have ammonia present in the water. What is probably happening is that free swimming bacteria are multiplying whilst they are feeding on the ammonia, this is why the water goes cloudy. Personally speaking, I think you need to find a new home for the Oscar as soon as possible, or get a new tank ASAP. I don't think you can possibly keep the Oscar in that kind of environment any longer without causing serious harm to its immune system, or maybe even killing it.

To find out whether I'm correct or not, you need to test the water for ammonia, nitrite and nitrates. What kind of filtration have you got? How big is this sucker fish. I am afraid that your situation doesn't sound too good. 20 gallon tanks are only suitable for very small fish like tetras, danios etc they are not a big fish tank.

im not killing him. ive grown to love him. i put him before the other tank that i have. he eats the best food and i take his water to an aquatic shop to have his water tested. it was cloudy cuz i washed his media in tap water. i put a new filter in and with in a day it was clear again. he does not seem to be unhappy. the only fish that is in there is a sucker fish and they play all the time.

Sorry, I think you misunderstood me, I'm not asking you to kill it, I would never do that. Not unless it was ill.

What you have got to understand that the bacteria in your filtration system can be wiped out really easily if washed in tap water. If this happens, you would have to cycle your tank all over again. What you should be doing at the moment is checking your ammonia every day. The water probably went cloudy because there was no/or little bacteria in the filtration system to take care of the ammonia.
You say you have put a new filter, are you talking about the sponges? If you have replaced all the media, you are going to have to keep a very close eye on the water and probably have to do 25% water changes every other day to keep the ammonia level at acceptable level. There isn't really an unacceptable level, you just don't want it to get too high.

Carry on as you are and wash the filter in tank water in future and your problem of cloudy water shouldn't happen again. In the mean time keep testing the water and if the results are not acceptable (ammonia 0, nitrite 0 and nitrate below 40) then do more water changes until they are

i have a filter system that has those replaceable filters with the carbon already in it. i did not say that you asked me to kill him. i said being in that tank is not killing him. i tried to put a picture up but i guess it is too big. my oscar seems happy he eats ALL the time and plays with the sucker fish.

What is the name of your filter? You talk about changing the cartridges, I am assuming this is mechanical filtration and not biological filtration?

The one thing that we don't do on this website is jumped down people's throats. However, I believe in being honest with people. Exactly how big is your Oscar. I know it is probably difficult to measure, but approximately how many inches/centimetres long is it? You have got a 20 gallon tank, I have got a 20 gallon tank here, it is my hospital tank so I know exactly how much space you got to play with. You are keeping an adult Oscar with a pleco. Depending on how big the fish, I find it very difficult to understand how you can keep that tank without having ammonia present all the time. There might not be much present, but even a small amount is highly toxic. Sometimes fish might not show any signs of stress. Problem is, they are being poisoned without you realising it. A lot of the time, their immune system is seriously damaged which opens them up to diseases.

Do you know when you're getting your new tank? Your situation is not good, I have to tell you that. What is your feeding regime, I would feed your Oscar every other day, and only once. This will reduce the amount of waste that goes into the water.

Given your situation i would not feed your fish much. You don't actually have to feed fish much to maintain them. I bought some tinfoil barbs at about an inch long from a fish shop once and by the time mine had grown to about 5 inches, the ones in the shop were only about an inch and a half. That was because the shop hardly fed them


Also i would do 50% water changes at least once a week. The more often the better. Do this until you can get a bigger tank. Check the classifieds, people are always selling fish tanks

my oscar is about 8 to 10 inches long and pleco is about 6 to 7 inches long. my filter system is called Whisper its for a 50+gal tank.
i got that one since the tank is not big enuff for oscar. it helps clean the fish waste and food.

and as far as his food, i feed him freeze dried large krill twice a day and a cricket or earth worm once a day. he always seems hungrey tho. he will splash the tank wen i walk by to get my attention.

Oscars will constantly beg for food. It has been said they are professional beggars. Just don't give in. Mine beg for food after half an hour after being fed!!!

Feed your oscar once a day what he will eat in 3 to 5 mins. You could quite easily get away with feeding him every other day. You might want to consider cichlid pellets as well as what you are feeding. The more varied the diet the better