I got this chalice frag about a week ago and just noticed a couple dark spots appear on it. Wondering if I can get y'alls take on them. I dipped it thoroughly and the closest coral to it are zoa's so I would be surprised if this is a result of a sting. Any ideas what this is and what I should do about it if anything?
Also, don't mind the sad goni in the back. He was a rescue project that I am not giving up on. Also, the zoas in there are closed because I just disturbed them!

Also, don't mind the sad goni in the back. He was a rescue project that I am not giving up on. Also, the zoas in there are closed because I just disturbed them!
