Black Spots on Tang

[kxnji]

Hi all! So I've been dealing with ich in one of my tanks for awhile now and have been treating with polyp lab medic. For the most part it's been working but I see it come back once in awhile. This morning I woke up and found that my tang had these ich and these little dark patches/spots. Can anyone ID what it is? Should I just setup a QT with copper now?

 

[Jay Hemdal Verified Community Expert]

Hi all! So I've been dealing with ich in one of my tanks for awhile now and have been treating with polyp lab medic. For the most part it's been working but I see it come back once in awhile. This morning I woke up and found that my tang had these ich and these little dark patches/spots. Can anyone ID what it is? Should I just setup a QT with copper now?

Some of those spots are too large to be ich. They are likely mucus plugs. I can see some smaller spots though, so yes, I would treat with Coppersafe or copper power for 30 days, in a treatment tank and then keep this tank empty of fish for 60 days.
Jay