This is my first post on this board so bear with me with the stupid questions. I just got my first tank, 55 gallon, ive got 1 peacock bass, 1 albino tiger oscar, 2 jack dempseys and 1 leapord pecostamus(sorry for the spelling). I first started the tank with three oscars, 1 albino and 2 tiger oscars. Both the tigers died, about a week apart from each other and it was probably due to the high levels of amonia and I think that they werent the healthiest of all either, but that was fine the guy at the pet store told me might happen. So I went to the pet store to find some replacements for the lost fish and I picked up a peacock bass(ocellaris cihcla, I think), so I thru him in and he had no problems. Couple weeks later the amonia droped so I thought it would be a good time to get some more fish so I picked up a couple of jack dempseys and they both are doing great. Well now my nitrite is thru the roof and fish seem to be handleing it pretty good, so a week goes be and all fish seem to be doing pretty good so I was interested in getting another fish, so I headed down to the store and sure enough they had another peacock bass, so i grabbed him and took him home, well hes been in there for about two weeks now and has gotten ich all over him and he is not feeding that well so I treat the whole tank because I saw some on the other fish well the other fish are doing good, no more white spots but the new peacock is not doing well, hes just swimming around slowly bumping into things not knowing what hes doing, so I took him out of the tank because I didnt want my other fish to catch what hes got so I put him in a bowl with a airstone and some ich medicine. Well i wake up this morning to find him dead. I just wanted to see if maybe somebody had this same thing happen, is it just the nitrite levels, i dont know just need some advice and it looks like you guys no what your talking about so if anybody has any suggestions I would greatly apreciate it. Thank You.