I just noticed this yesterday on the base of this frogspawn. Judging by it's size, I'm guessing it's been there for a while and I simply hadn't noticed it due to the color and the fact that the polyps hide most of the base during the day. I also noticed it has one small "bubble" (polyp?) on it. I did poke it with something just to see what it's texture was, and it feels like messing around with it would make it fall apart and disappear into the water column. It almost felt fluffy, for lack of a better word. I have no idea if it's a sponge or some bacteria or something else entirely. I did add a few frags to the tank a few days ago, but they'd been in my QT for months and I haven't noticed anything in that tank or on the new frags, so I don't think it's from them.
Here you can see the little 'bubble' on the right side.
Here you can see the little 'bubble' on the right side.


