I have turbos, astreas, and cerith snails in my tank for a while now. The turbos and ceriths are pretty active, the astreas not so much. The ceriths also really dig in the sand alot and helped eliminate any algae and diatoms I had growing in the substrate. WIth 30 lbs of sand, defianantly consider ceriths or narsissus snails.
I also have a couple of emerald crabs and DWARF hermits that eat like mad. I was warned about buying the larger Scarlet/Electric/Etc. hermits, but these dwarfs are pretty much full size and very small. THey seem to get in ANY crevice.
I recently put in 2 peppermint shrimp to hopefully clear some hard to reach aiptasia but I hardly ever see those guys. I hope they are doing something in there
On another note, I wasn't sure they had enough to eat so I added a couple small pieces of dried seaweed to be sure. Next day I had an algae and diatom outbreak start so be careful feeding your cleaners. Aparently I had plenty for them without adding the seaweed.