Someone correct me if I am wrong but i would be willing to say that 99% of ich treatments will crush a reef tank, its not good for corals and inverts and stuff like that. I am sure someone will agree with this, but your best bet is to remove the fish, every single one of them whether showing signs or not, and leave the tank empty for around 6-8 weeks. That is the life cycle of the ich parasite and in order to get back on the right foot you want it gone from the DT. Even if fish are showing signs or not they could still be carrying it. This is just what I can recall from other posts on RS, i have never had the ich problem on my tank, THANK GOD, KNOCKING ON SERIOUS WOOD!!