[danny zubot]

This is only specific to my tank, which has no filimentous algea or sandbed algae.

EDIT*

Excelent:

Pistols shrimp/goby combo-will collect any unsightly snail shells, keeps the underside of rockwork clear of detritus, sifts through all sand.

Good:
Blue and brown legged hermits-for rock cleaning abilities
Zebra/fighting conch- for sandbed cleaning
Cleaner shrimp- for cleaning corals of detritus

Medium:
Any snails- really only clean the glass in my tank.

Terrible:
Olive snail-keeps sandbed mixed but is only seen once every other month.
Turbo's- knock over frags and die more frequently that other snails.