My Coral Beauty looked great for the week he stayed at the LFS, and did great for 3 days in my display tank. Then yesterday showed signs of ich.. white spots on fins and body. He was still eating, but I quickly moived him to my QT tank with copper in it. How long should I keep him in there?? I t looks like the white spots are already gone. Please help, I don't want to put my other fish at risk, but I don't want to keep him in there lonmger than nessesary.