Hey everyone I have a purple tang in qt rn and it has a single spot on its dorsal fin and has since I got it. Not gotten worse or better in any sense I’ve been watching the fish like a hawk. No medication has been dosed and the singular spot hasn’t changed. It also doesn’t really protrude the way ich does. Here’s the picture please let me know what you guys think!! All the other dots in the pic that aren’t circled are just from the HOB filter dropping water back in