greyish stuff under my live rock

[stan450z]

greyish stuff under my live rock. have no idea what it is. only showing under one rock and not anywhere else in my tank. sorry for the horrible pic. its tough to make out also but i think yu can see what im talking about. if its bad should i get rid of the rock? replace with a good one with coralline algae all over from the store and hope it spreads?

[Sniperhank]

Sounds like a sponge. Harmless.

[stan450z]

Originally Posted by Sniperhank

Sounds like a sponge. Harmless.

Here's a clearer picture. It coats the entire bottom do you still think it's a sponge? It doesn't really scratch off.


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[Sniperhank]

Is it easily blown off?

[stan450z]

Originally Posted by Sniperhank

Is it easily blown off?

no it does not. i have a little bit of sponge growth on my in one part and looks nothing like this. its more of a gray/blueish.

[Sniperhank]

Then I'm not sure, I really can't see it. I'd still suspect a sponge.