Not sure what this is

[Thor2j]

So I haven't added any fish in over 2 years. All seem very healthy. Have approximately 13 fish in 150 gallon. I recently had a bunch of home projects done including wood floors glued and kitchen cabinets painted. I choose the people I did because I had a bad experience with wood glue before and these people use low voc products. I even ran a skimmer line to the outside of my house. A couple corals tool a little hit but nothing too bad . I have a ton of coral including a lot of sps.

I just noticed on one side of my naso tang he has a ton of what looks like pot Marks. Hes acting fine and eating fine. I did add a bta about 2 months ago but from what I understand they are pretty mild.

Here is a pic. Any ideas??

 

[cloak]

Maybe something stung it? This would be my first guess.

Do you have anything else in the tank that can do this besides the anemone?

 

[Thor2j]

Maybe something stung it? This would be my first guess.

Do you have anything else in the tank that can do this besides the anemone?

Hammers and frogs but they've been there for years, just bigger.