Ich comes and goes. It's part of the lifecycle. My blue hippo and purple tang have ich on them and I'm leaving them in there. They swim and eat fine. Occasionally I see the blue hippo getting tickled by the cleaner shrimp. I don't see them brushing on the rocks or the sand so that's a good thing. I'd only remove the fish if they were seriously plastered with ich or if all my fish had a good amount of ich on them. If they are breathing rapidly or sitting in the same spot would be a bit more concerning for me.