Unresolved Whats this on my powder brown

I thought my powder brown had a small outbreak of ich, yesterday he looked like he fought most of it off but I wake up this morning and he looks like this. It does not look like ich so I guess I was wrong.

The powder brown is still eating fine and attack seaweed when I put it in. He did have a small fight with my sailfin and has a cut on his right side but they get along fine now.

I also lost a tomini tang yesterday for what appeared to be no reason it just stayed on the bottom not eating.

 

Does not look healthy - that's for sure.

Looks like an open lesion. Could be secondary infection from something else or it could be a fungal or bacterial infection.

I see you had lost a tomini recently - sorry for your loss.

Could you answer some basics on the tank to help us qualify your issues?

How old is the tank?

How large is the DT/System?

I see you have a PBT, a foxface, coral beauty, as well as a damsel - at least. What other tankmates share that system?

Hope all turns out well!

 

Tanks is at least 5 months old that's when I got it. But it was already running when I got it, tank is a 110g corner tank with a 30g sump filled with approx 10g of water. Tank mates are Foxface, coral beauty, damsel, sailfin tang and PBT.

I am hoping the Tomini didn't bring something into my tank. I don't have a quarantine (i know big mistake) but I have never had a problem from the LFS I get my fish from.