Good link ^ ... I know many swear by garlic, I have never though it would cure ick in sw fish, put I have seen it said a lot - as to it benefit as an additive for health, I am still not sure, I have never used it, all my fish eat like crazy, everything I feed. Might help ... I don't think it hurts... but I have never used it, only read about it from post.
Might add... I am a huge believer in hanging nori for grazers... it's effect on thier health & help keep down stress that can lead to all kinds of problems.