They have been there for almost 8 months. None of my other goldfish have lumps like this, just this one. At times all the other goldfish chase him and pick on him to where they are pushing him(or her) into the gravel. I tried to separate this fish into another tank, but it stressed the fish out so much that I put it back into this tank again. What is it? And is there anything I can try to help it get better? I’ve done the aquarium salt, pimafix, melafix and even tried Ick medicine. Nothing is working.