Looks like bubble algae

[giantxtc]

Anybody know this algae?It grows in small mats about the size of a thumbnail or so.Some of it can be easily picked off the rock,and other pieces grow down into crevices.Emerald crabs don't touch it so far,and I have been manually removing it.When I first saw it in my system,it popped up almost overnight.Thanks for any help!

 

[graveyardworm]

Here's an article which may help.
http://reefkeeping.com/issues/2002-02/hcj/feature/index.php

I have had the regular bubble algae for some time now, adding a refugium seems to be helping, there is less and less of it. I do have one growth similar to yours which hasnt really grown fortunately. Finding a predator is going to be tough, manual removal and control of nutrients is important to winning the battle.