My friend has a 65 gallon tank that houses a irradesent shark, a large pleco, a silver dollar and a schbunkin goldfish (I don't think I spelled that right) I know the schbunkin should probably not be in the tank to begin with but she had them when I met her. Anyway the shark and the schbunkin got in a fight and the shark by far got the worst of it and we are trying to figure out what to do to save him. He has several scratches and is covered in what looks like a fuzz all over his body. He is up right but lays on the bottom of the tank and does not want to eat the fight was night before last and they have been seperated and the schbunkin is doing fine but the shark is her favorite and she is very worried about him. I suggested salt in the water as well as a water change but is there something else she could do?