When can I add pom pom crabs/s?

[Medici]

I've had mine for over 2 years, his name is Frank. You can pretty much see him after 11pm on any night after all the lights are off. Never had to target feed him. He lost his anemone's a long time ago, but he somehow has 2 new ones now, I don't have any small anemones or aiptasia. He's super cool though, one of the best parts of the tank. I would wait at least a couple months before adding one though.