Keep in mind this is only my experience: I had/have ich in my 125 now for atleast 6 months. Right now, my fish list only consists of 6 blue chromis, a copper banded butterfly, and a scopas tang. There was a point when the tang showed multiple signs of ich, but not anymore. I have 3 cleaners and feed my fish food with some garlic on a daily basis. As of today, none of my fish have been showing any sign of ich for well a over a month now. Although I understand that the ich is still supposedly present in the system, my fish haven't shown any signs at all. Until I notice it being a huge problem, I'm going to let nature handle it. Keep in mind that if you do try and go this route, it will take a little time for your fish to get accustomed to your cleaner shrimp approaching it. Hope this helps