Heavy breathing. Been through copper

[acomps]

Hello my tang is breathing heavy and recently started to hang out by powerhead. I had him through 30 days of copper along with 3 rounds of prazi. The rest of the fish in the tank are showing no symptoms. Every fish in my tank has been through copper. It developed hlle while in qt. Any suggestions? Fish is eating and ammonia and other specs are good.

Thank you

Any suggestions? Thank you.

 

[acomps]

And I might add no twitching scratching flashing etc. mostly normal swimming besides the power head and heavy breathing