I’m new to this so I don’t know how bad this can be so I put it as an emergency, I’ve got the pair of clown fish about one month ago tank is 3 months old. When I got the fish they both swam together fine, but after a water change the smaller one has been having trouble swimming up. Both fish seem to be hyperventilating. I have a 13 gallon tank and I haven’t put anything new in there, there aren’t any spots so I’m not sure if this is an infection or a damaged swim bladder, my O2 should be fine so I’m not sure what the problem is