What Is this???

[brittaniw]

I think its dead, it came in on my live rock...I just wonder what it could be.

[roka64]

Are you talking about the red stuff? If so, it is coraline algae (good stuff).
If you are talking about the white/tannish stuff, it could be a encrusting sponge (a harmless filter feeder).

[brittaniw]

Yes I mean't that spongy thing... I probably should have circled it in paint or something sorry about that, but thank you.

[Devilishturtles]

I agree it looks just like an encrusting sponge. If it starts looking nasty you may want to remove it.

Welcome to AA, btw.

[Ziggy953]

I have them growing all over the place in my tank. The ones exposed to direct lighting will probably die off anyway as they like shaded areas.

[melosu58]

They are growing all over my tank as well. Sponges.