Firefish, Bubble Algae and Emerald Crabs...

[FishTri]

I have a firefish in a 55 gal quarantine tank, along with some corals I recently got.

The corals have some bubble algae and I'd like to add a couple of emerald crabs from another tank to take care of the bubble algae before I move the corals to my main display.

I'm worried about the firefish. He sleeps on the sand under a ledge of rock. If I put the emerald crabs in, will they start nipping at his fins?

[Animal Mother]

They shouldn't touch it as long as they have plenty of food. They are opportunistic, but very rarely attack fish. I wouldn't worry about it unless it was sick or weak.