[refhater]

I have to agree with Jadinop...oodinella or ich type parasites. Tangs can be quite susceptible. I would think about taking him out and treating him in quarantine if you can. Much easier and safer than treating the tank. If that isn't an option, then something non-copper based like No-Ich might be an otion.

 

[refhater]

Pretty fish. If it is losing color it could be from stress of fighting the specs of white!