Genin
New member
I was going to get some live rock rubble to put in the corners of my tank to stop my obsessive compulsive perculas from digging in them. The LFS told me that they'd give me some rubble and old dead coral pieces for $2 so I said great. Well I noticed after a few days that there was a small dime or nickle sized piece of something growing out of this dead coral skeleton.
Here's some pics...What do you think it is?
Here's some pics...What do you think it is?

