ID request please

[conefree]

I noticed this white substance growing near my Frogspawn. Whether or not this has any bearing on what it is, I have no idea. Any help would be appreciated in figuring out what this is. Thanks in advance.

http://i37.photobucket.com/albums/e75/conefree/Tank%20pics/100_4082.jpg

[crzy4reefs]

don't have a specific name but it's either a sponge or part of that family i have it on my rocks for years hasn't done any damage.

[conefree]

Thanks for the quick reply. I was hoping it was something benign. Anybody else seen this on their rocks?