I just got 2 Hippos, wild caught from Aquarium Warehouse. They are doing great!! They are also eating planktonic foods just like the anthias as well as grazing all kinds of algaes.

I have 116 hermit crabs (104 mexican blue legs, 12 carribean scarlet reef) in my 125, an emerald crab and decorator that eats algae only. My rocks are covered with little dusters, tunicates, vairous polyps of all sizes, spontaneously generated tubastrea corals and sponges. I have some very small fish in there too and a tank raised seahorse. The exact crab species matters. They are clean up crews, not eco-terrorists as termed by some. They only eat fish if they are dead first. I have tons of stuff growing in my substrate as well, like hundreds of tiny brittle stars, worms, limpets, chitons, shrimp, crustaceans. Zoos, mini-zoos, shrooms, leathers, stars, sps, etc., etc. Those crabs don't touch a thing in there.
A 1.5 inch hermit is the wrong species.
I'll take all your blue legs and scarlets, just bring em to the meeting or I can come and get them. Just let me know.