I have one....it stays in the sand, and is just as hardy as a normal hermit. The hermit eats, and the scraps are eaten by the coral on his back. 440 VHO here as well. I had another, but they fought it out until one was dead. I placed his coral high in the tank, but it quickly died without the crab. They say to keep empty shells away, or he may switch to a normal shell, and you'll just have an expensive hermit......mine has never left his home. They grow, and as they do, they drill out a bigger hole to live in, so they don't really outgrow their coral. The coral is a different story, but by the time the coral gets too heavy, the crab will probably have died. Anyway, I have found them to be just as easy as a normal hermit in my experience. Cool little guys, but after mine fought it out for no reason, I wouldn't add two....just my experience though.