Hair Algae Eaters
Astraea sp. snails (often referred to as Astrea snails) range in diameter from about the size of a nickel to almost the size of a quarter. These snails will consume film and hair algae on the glass and rocks in your aquarium.
The Babylon Snail is a large scavenger that will stir sand beds down to 2 inches in depth. They have the potential to consume other small snails but are generally considered reef safe.