Naso needs Help

[saltwatergator]

ok, I added a naso tang and huma trigger to my 90 gal tank about 5 days ago. I had nothing else in the tank except for 5 damsels and a red coris wrasse who enjoys the sand bed. The tank has been up and running for 6 months now. Stupidly, I added the fish into the tank without quarantining them first. At first they seemed alright. Two days after adding them I noticed the Naso had several white spots under one of its pectoral fins and the huma starting to rub against the rocks. Since the tank is a fish only, I decided to do a hyposalinity to kill what I believe was ick. Now I have notice an open sore behind the pectoral fin of my poor Naso. Please help.
The filtration is a wet/dry with a UV sterilizer.

 

[beth]

Doing hypo on a 90g is a lot of water changes!
Have you noticed any aggression? How big is the sore?

 

[saltwatergator]

no, the huma is only about 2.5 inches and rather passive. The sore is about 1/4 of an inch in diameter and the fish is about 4.5 inches long

 

[beth]

That's pretty big. You just noticed it? Has it been getting bigger? Does it look infected, bloody?
I would not rule out aggression. See if you can keep an eye on your tank wo your fish noticing that you are looking at them.

 

[saltwatergator]

I noticed it early today. I noticed a white spot in the same area and thought it was just discoloration from stress two days ago. Today I finally noticed the sore. No bleeding, just a white pit in the side of its body. I will keep on checking up on him.