I’ve had this acan for about two months now with no problems and when I checked my tank this evening I noticed several odd ‘bumps’ on it. They look like little white spots but each ‘spot’ is made up of several little pieces. I’m not quite sure how to describe it. (Will add a picture below it may be too poor quality to help though) Could it be stings from my Favia? They were a little bit closer together (about 4-5 inches apart on a frag rack and I have moved the acan completely since I noticed the marks) in the image if you look at the bottom right polyp you can see a couple of the spots I’ve been talking about.