What’s wrong with my red monti cap?

[Tuan’s Reef]

Don’t know if it was there before I bought it but I noticed it’s few days ago. Bought it like 2 weeks ago.

I can see some discoloration around it too. What I’m I dealing with ? Pest ? Or water params?

Here’s my params , been doing testing nightly since dosing 2 part .

 

[Gareth elliott]

Any corals near it(within 10 inches or so) like a torch
Or any hydroid?

 

[Tuan’s Reef]

Nope. It’s alone on this rock

 

[Gareth elliott]

Well the anemone could have also caused that mark.

 

[Tuan’s Reef]

lol, my RBTA is whimp. Hasn’t moved from that spot since the 2nd day he’s been in the there. My cleaner shrimp even harrases it .

 

[malacoda]

You just got 2 weeks ago. Is it possible it got bruised or scratched during dipping or mounting?

 

[Reefer45C]

my red monti cap (which is highest in the tank) did that after a rogue piece of salt creep fell on it while cleaning the return nozzles... it was a very tiny piece and I blew it off the cap with a turkey baster. the next day a spot like that was on the cap but after a day or two it was back to normal.