What is this?

[TonyD1988]

Sorry I know the pictures aren’t the best but any ideas on what my yellow eye tang has? She was in QT from the LFS. I’ve had her for a couple weeks now in my 300. Past few days she’s been swimming lazy and favoring her left side. Flesh appears to be kind of melting off.

 

[Joseph Disalvo]

Uronema ? Bump

 

[TonyD1988]

Fin rot?

 

[TonyD1988]

Update: fish died overnight in QT. Parameters tested last night were
Ammonia: 0
Nitrites: 0.1
Nitrates: 5-10
Salinity: 34 PPT
Temp: 78

All other fish seem fine so hopefully none of them get sick from this.