and out it popped

[rabid frog]

I just bought some new lr and i got a littel surprise with it, out skampered a litle emarald green crab, are they reef safe, i.e. for my future mushrooms and such??

 

[b_ball12_99]

When their little I think they are but when they get big they can become somewhat aggressive.

 

[wolffam]

Emeralds will control the green ball algae, should it arise. I've heard that the are reef safe. As with any thing that grows it can and will rearrange some rock,