Separating sick fish from asymptomatic fish in QT

[Master of Cloak]

So I have a tang and some chromis in quarantine. They have all gone through 30 days of copper at therapeutic levels. The tang seems perfectly healthy and isn’t exhibiting any signs of disease. The chromis however have urenoma. I have begun treating the qt tank with metroplex. The copper still remains at a therapeutic level. My question is would it be possible to remove the tang from the quarantine and add it to the main display tank? Any clarification would be appreciated.

 

[Hincapiej4]

Oh god..uronema....