Bought an emerald crab last week, put it in the 42 gal hex. Hadn't seen it until tonight shortly after lights out. Man, it was chowing down something fierce on what I believe is bryopsis - green, short-growing wiry algae, and leaving the red wiry algae, that's intertwined with the bryopsis, completely alone.
I consider that pretty good news, but not as good as if it was going after the valonia that's scattered all over the place. Glad it's not going after any corals or anything, too.
Right now, I consider adding the emerald crab to be a partial success
