So I all of a sudden have ich on three of my fish, when I say all of a sudden, I mean all of a sudden. None this morning, I look at my fish constantly, then boom this evening you would think someone used a white pen and put dots all over them. I have a blue hippo, flame angel and copperband butterfly that have it, my 2 maroon clowns are fine. I have no idea what would cause this all of a sudden, the fish have been eating fine, swimming and very active, so signs of stress. All of my parameters have been great, 90 gallon FOWLR tank. QT may not be an option here considering I have three fish with it and I know the flame angel is very sensitive to elevated copper levels so meds may not be the answer. I really need to try to do this in the DT if at all possible. Any suggestions as to what I should do here.