I don't know if I'd
copper the hospital tank. Some fish are very sensitive to
copper. Best thing to do in my opinion is to just quarantine them for a month and keep a close eye on them. If they don't show any sign of ich in that amount of time, then most likely they don't have ich. My blue hippo tang used to have ich and just could not get rid of it. I put all my fish in hyposalinity (1.009) for 6 weeks. At that point I KNEW my tank had no ich and my fish showed no signs of ich. That was 4 months ago, and even my blue hippo has showed NO sign of ich. Whew!
