Not sure what I did if anything other than keep em fed real good. But for some reason my yellow tang almost 3 now caught black spot about 4 months ago. Have no idea where in the world it came from unless it came in on some frags that I didn't dip. Anyways I have read that it isn't very deblitating and to monitor him and just let him be....I soaked all food in selcon and garlic. I didn't hypo him or QT him since that might have been impossible to catch him without tearing the whole system down. It never seemed to bother him that bad and he kept eating like a champ so I just went with it... The black spot would be really bad for two-three days and then fall off and come back worse over the next week or so just like ICH...Well I am happy to report that it has been almost 60 days and knock on wood haven't seen on spot on him since. Has anyone else very seen this happen. Can it just be fought off or can they build up some form of resistance. Would like to hear from others on this.