I've got this fleshy bubble on my red planet. It looks like it's full of water or something like that. I don't see any bugs or anything like that. My phos is 0.00 hanna checker, alk around 10.5, cal 450, ph 7.9. It still seems happy and everything else is happy. I'm not so experienced with sps. Should I be concerned about this?

I don't have a clue about the "sac"

