Hey guys, new tank set up and I got this piece of live rock from an LFS. It has what looks to be so much old growth on it. I’m assuming the porous encrusting spot is sponge but what else is on here? Can anyone help ID what this stuff is. I found it in a giant bin of live rock and thought it looked cool so I bought it. I just find it interesting to see what is living or once lived on this rock. Also could any of it be dormant and come back, particularly the sponge? Thanks for your time and insight!


