Sponge Id

[Madreefer]

This sponge grows in my tank and I kinda like it. Is there different types or just basically a sponge? Seems do do really good when I start adding some zeo products again.

With flash
http://i255.photobucket.com/albums/hh135/gulflube/top004.jpg


and without
http://i255.photobucket.com/albums/hh135/gulflube/top005.jpg