Help Confirming Ich, need advice on shuffling livestock

[marie]

If you're going to treat the clown then you will have to treat all the fish and leave the DT fishless for at least 6 weeks or else the treatment will be pointless.
At this time If I were you, as long as the clown is still eating I would leave it alone. Ich in itself is not necessarily deadly, it's just an opportunistic parasite that target fish with weakened immune systems.