I actually have an emerald crab in my tank but honestly I have never seen him do anything other than sit in 1 of my acros at night. Luckily he doesnt seem to be doing any damage.
As far as manual removal goes i have been siphoning them out when possible or if they are imbedded in my rocks then i burst them and siphon out the guts. Now a fellow told me he got rid of his by just popping them all and eventually they never came back. This goes against everything we were always told about valonia, this causes it to spread. However upon further discussion we surmised that an emerald crab just bursts them and couldnt possibly eat all of the guts so what gives? Well we think that perhaps because the Emerald is only bursting the small ones, and these are probally not sexually mature yet, so releasing thier guts is a moot point and they wont spread. Given enough time the population would eventually perish. Has anyone else had any experience popping them and had them go away? Having said this is there anyone out there with access to a microscope who would be able to look at the bubble guts at various stages of growth and see if there is any evidence of spores?

I had valonia in my 33 gallon, and tried just about everything to get rid of it including emerald crabs, manual removal, and eventually popping them. :Cry: The only way I got rid of them was when I switched all my rock over to my new 125 gallon tank, flipped all the rocks upside down crushing and burying all the valonia into the sand, and I have never seen them again. :twised: have no idea why that worked, but it did.

it would seem to me that while they are popping a few and causing them to spread they are also eating all the small ones. eating the young out of a population long enough would get rid of them.

Thats what I am hoping for but I am going to have to try and do it manually because my emerald crab seems to ignore them.

My naso tang loves to eat it. I also had a foxface that ate it.

I never had an outbreak but it was present. After I introduced a kole tang I haven't noticed any more.