[Stanfill Reef]

I need help identifying a black growth on one piece of LR. Two pictures are to follow. The growth is very slow but seems to eventually want to cover the entire LR. The white spots are not bubbles, but sand. I have tried vacuuming and scraping. This stuff does not want to come off. Any ideas what it is? Do I want to get rid of it? If so, how?

Thanks for your help!!!!

 

[Stanfill Reef]

Picture #1: Whole rock

 

[Stanfill Reef]

Close up view of left side of rock:

 

[ckreef]

Had to tell but looks like a sponge to me.

 

[Joel]

I have what looks to be the same thing in my tank, feels like a sponge and peels off very easily (mine does anyway)

 

[Stanfill Reef]

Sponge....hadn't thought about that. It is pretty slick and soft, but it is in a very thin layer, like algae. Any other suggestions, or do we have a winner?

 

[horge]

Better late than never.

Lobophora variegata
It is a brown macroalga, and a recognized troublemaker.

Here is some more info:

http://mabma.thereeftank.com/genus_lobophora.html

I seem to remember swapping horror stories with Jenn Myerscough about it way back. She may have some other info to offer...
hth