Hi, so i posted months back and no one really knew what it could be, its now gotten bigger and doesn't look nice at all, but how do you decide its too much for the fish? He still swims, still eats and seems okay but i dont know. We are guessing its a tumour and not much we can do to treat it! The pictures arent great but its the black growth on his head! Do we assume hes ok.atm because he is still eating etc?