white mass growing under one of my rocks -pic

[srossnz]

Anyone know what this is? It wasn't there when I got the rock a month ago, seems to keep getting bigger! I can't tell what it is and it's hard to photograph.

http://img515.imageshack.us/img515/1198/whaths7.jpg

[judgemax]

a sponge maybe?..

[Grins]

The pic is really grainy but I'd guess a sponge as well.

[srossnz]

Is that a good thing? Will it gobble up nasties in the water or make them? I wonder how big it will get. I'll try to submit a better pic soon

[skippy2]

It looks like a sponge to me too. Do you see any syphon tubes on it? That would be a great indicater. They are a filter feeder so good for your tank.