Frag tank clean up crew recommendations?

[bkelly]

My frag tank feeds off my sump return line from my main tank , then returns back to the main tank sump. I have 2 powerheads in it its about 20 gal and i have 150 watt MH lighting. Corals are up on egg crate, i put 2 clowns in there for now with my corals. The clowns were getting terrorized in my big tank so its kinda a refuge. The frag tanks newly set up , my main system is pretty clean of algae. i notice a bit of algae starting to grow on the frag tank crating and bottom. What can i put in there to help deal with it not getting out of hand? I threw in a couple hermit crabs to clean up any excess fish food...
I was thinking snails may start knocking my corals over. How about a tang (i got a kole i could trap) any other recommendations. for now i think its best i keep the clowns isolated there.
thanks
brent