Emerald Crab vs Bubble Algae?

I had some Valonia when I first started my tank.  I put in a couple Mithrax crabs and the Valonia was gone within a week.

 

Thanks for the replies.  Initially I had a Emerald Crab and he seemed happy.  But I have not seen him for a few months and I wonder if he died from starvation.  He/she would come out to devour the shrimp pellets I would drop.  But I decided that the shrimp pellets were putting too much into the water and I stopped feeding with them except on a rare occasion.  I didn't have bubble algae before so maybe he ate whatever there may have been there, if any.  My tank is small and I try not to overfeed in order to keep the water prams decent and the algae checked.

I've got a start for you, Adam!

I recently put a rock with Valonia in my tank and was worried that it would grow too quickly, but within a couple of hours my yellow tang had it all cleaned up.  He was happy.  I can't grow any kind of macro in the tank itself since the tangs just clean it up on contact.  I do grow it in my refugium.