he was eating,before the change he was swimming,he didlooka little bloated,no pine-cones,poo was normal,,i had him for about two weeks,one fire gourami-one cherry barb(small)-2 blood finned tetras-1 albino pleco(small)-and 8 small cardinal tetras. all the fish i have mentioned all seem fine. the tank is 20 gallon,,about 2 months old..i have recently had a trace amount of nitrite,, so i have been doing 20 % water changes daily and i have also added some aquarium salt..sylvia said:Is he eating? Trying to swim? Does he have any symptoms of disease? Is he bloated? Has he got any pine-coned scales? Is his poo white and stringy? How long have you had him? What other fish are in the tank? How big is it? And what are your test results for ammonia, nitrIte, nitrAte and pH? Have you made any recent changes to his environment - I'm particularly considering the addition of pH-altering ornaments like bogwood and the like...?