Mits

I have a small (3 in. or so) hippo tang that I've had since around Thanksgiving who has been very active and healthy, but he seems to get small outbreaks of ich that go away by themselves. Last week he was pretty bad, and in the time I got the stuff together for a treatment tank he got better. Last night he had several spots on his head, including one pretty big one, and on a couple fins. Today I can't find a single spot. Should I treat him for it or is that something that will just come and ...