Just don't put copper/Cupramine/Coppermax in the display tank that coral will go back into at any point. You can eliminate ick without medications if you run the tank at hyposalinity, which is about 1.009 specific gravity. Coral have to be removed to do hypo and you should probably use an ATO to keep it at 1.009.
Many fish tolerate hypo well, but some will not. If you decide to do that, be sure to slowly raise salinity back up when you are done (like over the course of a few days). If you decide to do hypo, you will want to run hypo for as long as you would do a fallow run (up to 72 days) to be sure to be rid of it.
I'd still feed my fish Metroplex and Kanaplex bound with Focus to kill internal pests that they may be carrying to cover other bases.
I would expect inverts to take a hit in hypo as well, if you decide to do it (not sure).
Good luck, and I hope whatever you decide to do works for you. I QT with hypo and feed medicated food as described with great results.
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