Yeah I spent like 10$ on some reef safe stuff that supposedly contained no copper when my blue tang had ick when I first got it. I never had the balls to try it, It now sits in my closet unopened... I wouldnt risk it though in a display tank. Just feed garlic and or selcon and hope the infected fish gets better. It stressful on a fish getting caught and put in another tank a lot of times, even worse for it than the initial disease... At least that was my issue with the blue tang when I got it. (who pulled through it and has been great for months now)