Nerite snails are smaller snails, yet useful as part of the clean up crew in your tank. Nerites - Neritidae sp. - are algae grazing snails, but they have a bad habit of crawling right out of the aquarium. If you own a rimless aquarium, you'll end up finding some on the floor unexpectedly. Tanks with eurobracing or lids/screens should be able to keep them corraled. They consume film algae and other turf algae. Nerites tend to be about 3/8" in diameter upon purchase, and may grow to be as large as 3/4" in diameter.