Hello, Quick question-My clown has some kind of parasite on it dorsal fin. Its pretty aggressive, within a week it ate so much it exposed a bone! I can easily get the fish out of the tank in a QT, but my question is what should I treat it with. If I use copper, can that contaminate the tank when I put him back? I was worried about the copper solution on the net when dipping him back? How about a fresh water dip and what is the recommended salinity for that?