What is this on my rocks?? Help???

[RubixCube]

I recently added some lr to my 77gal. Its in the process of cycling now. But i have been noticing somthing on part of one of the rocks. I just read this:

"After live rock has been added to an aquarium, keep an eye out for any white filmy or black areas on the rock and remove them. These are dead or dying organisms and can quickly pollute your water if not removed. "

And thats what it looks like, a filmy substance. Anyone know what this is and weather i should remove it or leave it. See attatched pictures. (sorry for the size but i needed to keep the quality up)

 

[RubixCube]

the other two pics i have

 

[reefrunner69]

Dude!!!!!!!!!!!

Your LR has rabies!!!!!!!!!

Actually it is a sponge

 

[RubixCube]

oh man... and im all out of tetnis shots

 

[RubixCube]

Sponge?

 

[reefrunner69]

yep, looks like a non photosynthetic filter feeding sponge, most likely it eats silicates out of the water. Even though it doesn't appear to be fouling now does not mean that it won't. As the ammonia goes up in the tank it is likely to die. If you notice some whitish gray spider webs engulfing that rock, that sponge is most likely the cause.

 

[RubixCube]

what should i do with it? The ammonia has been high in the tank since i have put the rock in (between 2 and 4) Am i killing it?

I cant seem to find any information on this type of sponge at all.

breif description:

honeycomb texture
hard
sandy beige in color
Almost looks like brain coral

 

[fishfreek]

Its a fairly common sponge to find on live rock. What I would do is pull out each rock and give it a good smelling. When you find the area that is dead/decomposing you will know it. Take a stiff nylon brush and scrub that area good and rinse it in some saltwater before putting it back in the tank.

Perform a water change aswell in your tank with fresh saltwater to lower the total ammonia level some.