Another link to a thread about ick.... very long.
http://reefs.org/phpBB2/viewtopic.ph...&highlight=ick
The reason I did not offer up a opinion right away is so many people have so many ideas that you have to do what you think is best. There are only two 'proven' ways to kill ick, copper and hyposalinity. It's a science not some mystery. It's a animal/parisite a obligate protozoan, they know it's life cycle and how to kill it. People will say they this and that worked for me, yet they get it again so no it did not work the tank still has ick. It can't be seen so thats OK for most. Then some thing happens in your tank, your fish stress and wow ick is back.
You can patch it with a band aid so it looks like it's gone or kill the parisite for good. I'd rather not depate it, so I told you to read lots. The more you or anyone reads the right info regarding ich I think you would agree. Do a search on reef.org if you don't agree and let the endless threads debate the topic for me.
My last post I gave you my opinion on what I would do and also asked the details on your tank. For larger tanks removing one fish is all most impossible and the parisite would still be present in the water so removing one fish would be useless. I still need all your tank details but I'm sort of assuming it is smallish and I'd remove all fish into a QT tank and let the tank go fallow(sp?) for the required 5-6weeks. You have damsels in your QT tank so get rid of them or get a new tank. Do the hyposalinity in the QT tank and be very strict about Qt'ing all new fish. Here's another good link and it's way long this is part one of five.
http://www.marineaquariumadvice.com/...um_fish_1.html
ICH SUCKS how is the fish and how big is it? I've tried most cures and IMO do what the pros and marine biologists say.
Dave