If you do used ht for your sick fish, switch them over at the first sign of ich when they're healthier. Thrn feed and medicate them. Doing freshwater dips are very stressful for fish. I've heard best results with copper and garlic for curing ht'd fish. If you have them in your main tank, use preventative measures like ht tank for new fish, garlic, uv serilizer, and keeping your fish healthy. Slow acclimation (both for water parameters and environmentally) of fish will reduce stress. I tried this stuff with nitroimidazole in it and it seemed to be working but its terribly expensive and needs to be dosed daily for weeks. I unfortunately had to leave partially throught the treatment so im assuming that and the lack of food is what killed my fish.