Can someone identify this thing??

[enomadra]

So I saw this thing on my live rock before I put it in but I don't know what it is. It kind of feels like thick foam but slimy. Oh and it was a brownish orangish color but now is white.

 

[wrassecal]

Kind of hard to tell from the pic. Is it a thick area or a thin layer? It kind of looks like bleached coralline algae. If so it should turn pink/purple after a while.

 

[bang guy]

Looks like some type of colonial Tunicate. Could be an everyday sponge though.

 

[larrylwill]

I second the sponge, I have lots on the dark sides of my LR. Different colors but mostley dirty white.