The best thing you can possibly do for your critters now is to QT them. Putting ALL your Fish into a Hypo environment will kill off any ich during their freefloating stage. A period of six weeks inside the hypo for your fish will permanently eliminate the ich parasite. Also by starving the ich parasite inside your display tank (as no fish should be there for six weeks) it will be eliminated there. The beauty about this treatment, is that its free and there is minimal stress on your fish/corals. But more importantly, once this treatment is completed you will NEVER get ich again. Unless you reintroduce it via new arrivals without quarantining them.