I fed my fish today and my pleco began to fan self and now my two cory cats are breathing heavily and pleco fans self every once in a while but corys are swimming around and digging in gravel but still breathing heavy all other fish are acting normal. fish include 1 blue phantom plec,2 lemon tetras,2 cory cats, 1 bleeding heart tetra, 1 cardinal tetra and silver hatchetfish after this started happening I cleaned the filter wich was really dirty and turned on a airiation power head I use for emergencies but my question is wat could be going on and I barely have any stress zyme (bio filter support) left so is this a prob and should I risk water change or just moniter and not feed till I get more stress zyme?