Can any one please ID the following SP

smooth, greenish and rubbery, I thought it maybe some form of algae or soft leather ??

Grows well under MH and good water movement.

looks like some type of sponge to me.

looks like some type of sponge to me.

I will take a better photo, i didn't think it was a sponge as it grows slightly different to the sponges I've seen, kind of fans out and is really smooth.

However my knowledge is limited. (but growing)

i am thinking it is some type of cryptic sponge.