Help Needed! I've had my fish for about a month or 2 now. I originally bought 2 but lasts week I went away, left a tablet thing in and came back to find my tetra lodged behind the heater and clearly dead. I now have my angel fish left but I fear it might have swim bladder disease, which I have researched and found symptoms for. I keep thinking the fish is dead as it keeps floating around, and when it goes under the filter it gets pushed downwards. If it is a swim bladder disease then my thoughts are that it may be from the pellet thing I put in the tank for food while I was away? Anyway help needed asap. If needed I can supply pictures.