QT help!

[agame2021]

I got to act pretty fast here. So I have 8 Fiji blue devils in a 10 gallon QT. One (the one in the video) has bruising pretty bad but all the others seem to be alright. How do I treat this guy for the best outcome?
Second day in QT I used 50% display tank water and the rest new.
Salinity is at 35.2 ppt.
Ammonia 0
Nitrites 0
Nitrates around 1.5
For a HOB filter
Heater set at 74
5 lbs piece of live rock
An aerator (need to get air stones shortly… rn just tubes with air coming out.)

I was going to start copper but would like your guys opinion of what to do! Thanks in advance.
(If the video doesn’t work hopefully the pics will be enough)

 

[vetteguy53081]

You can give it either 45 min bath in quick cure which contains Formalin or 90 min bath in ruby rally pro then treat tank with ruby rally pro which is reef safe
Increase oxygen with air stone during treatment