Just found 2 crabs in my tank

[naesco]

Originally Posted by Aquattro

Unless I have a crab living in a coral and doing damage, I almost never remove them. Unless they're big, or you have really small fish, they're all mostly fine. My rule is unless they do something bad, they get to stay.

I have been reefing for for 20 years and have never seen a crab attack a coral or fish.
They might I guess if you do not feed them. Drop a pellet in their direction from time to time.

I agree they are completely fine in your tank.