Go with an emerald crab. completely reef safe and just an all around good addition for a clean up crew.
NOT completely reefsafe. i and others have first handedly caught them eating zoanthids and other corals
I just moved my rose emerald to the fuge due to this, I think the co-factor was he started the size of a quarter and quickly became the size of a silver dollar. I also believe he is the one who ate my peppermint shrimp and some of the tentacles off my rainbow BTA....so off he went.