Is this tang healthy?

[Sinestro30]

Hello All,

had this yellow tang in QT for 3 weeks. Treated it with prazipro for the last 2 weeks. It eats well. Pellets, frozen and nori. Tank has had some issues with higher nitrite than it should, though these are fine now. Im wondering if it is starting with HLLE? Could this be caused by the high nitrite? The tank has had activated carbon in it before I started with prazipro.

 

[Jay Hemdal]

That does look like a bit of HLLE, it is often caused by carbon. Siphon the bottom of the tank really well and discontinue using it.
You don’t have to worry about nitrite in marine tanks, it is only toxic to freshwater fish. Ammonia is the real killer for marine fish.
You should consider giving the tang a copper treatment before moving it into your DT.
Jay