Blonde Naso tang sick???

[Kawasaki716]

Hello everyone, today I noticed that my blonde naso has some small dark spots on his lips, and his tail is looking a little strange in coloration, almost whiter than normal. Aside from that, he is eating great and is very active. His breathing seems like it may be slightly accelerated, but it's hard to tell for sure. He is acting healthy as can be so I'm inclined to think that this May be stress induced.
I recently took out about half of my tanks live rock, but my corals (sps + lps) look great, and so does the coral beauty angel which is the tangs only roommate... The only possible diseases I can see being the culprit are the black ich, or fin rot. But he isn't displaying any symptoms of discomfort whatsoever so I'm praying it's just stress... Any thoughts or input on a possible explanation of these irregular physical variations would be greatly appreciated!!!! Thanks for reading :headwally:

 

[Newsmyrna80]

How long have you had the fish and has anything new been added? Can you post a pic?

 

[Dmorty217]

Pic would help. Black ich is cause almost entirely by poor water quality. PP will get rid of it. Or I have also used paraguard

 

[Kawasaki716]

I've had the fish for about 8 months. Nothing new has been added. I have noticed that sometimes my tang will charge his reflection on the glass and occasionally bump the glass. Maybe it's the result of an impact?

 

[Kawasaki716]

He's too quick for my poor photography skills but I'm going to try again tomorrow if he doesn't look recovered. He's still acting fine at least..

 

[Newsmyrna80]

How big is the tank?