Advise for Healing Blue tang

[ifwisheswerefishes]

I have been managing what I thought was Ich in my display tank for 2 months. It seems that maybe Ich was not the problem, so I treated my DT with Prazipro thinking it was a really bad case of flukes. After 2 days time stuff started flaking off my fish like a human would slough off dead skin from a sunburn.
Is this a normal process or something I should worry about? All fish are eating well and swimming normally. However the Blue tang seems to stay behind the rocks when there is no seaweed on the clip.

 

[Qasimja]

what your writing as the condition sounds a lot like brooklynella are any of the other fish showing symptoms