I have a 135 gal fish tank with 4 oscars, 5 tinfoil barbs, and 2 red tail catfish.. I've had the cat fish for maybe about 6 months or so.. The bigger 1 is about 12" and the little 1 is about 7 or 8".. But recently maybe about 2-3 days ago they start acting funny.. Like they would just float at the bottom of the tank with their tails down and their faces up.. I don't know what could be wrong and I can't find any thing about it on the interent.. I read that it might be oxygen starvation so I put a air pump in there and there hasn't really been any change.. Any help would be greatly appriciated, I don't want them to die. Thank you.