esmithiii, The shrooms split, and grow like weeds in my tank. The good thing about them is my LFS trades me corls for them. He sells them easily. The tank is about 2 years old. I kind of thought is was some sort of sponge, but curiosity got the best of me. Thanks for the reply's.
Smokin- I was just kidding you. Looks like a sponge to me too, although I have not seen white ones in my tank. I have a yellow one growing on the underside of a rock that looks similar.