Red Onion Snail The red onion snail, or onion nerite snail, is a scavenger and algae eater and, like all nerites, plant safe. The pattern is a red body with small line patterns around the shell. Nerite snails do not overrun the fish tank and only grow to about one inch at full maturity. In fact to breed nerite snails need salt water. Nerites do well in most water conditions except for PH below 7.0. These attractive snails do not get bigger than an inch and we recommend several for algae control in larger tanks. Scientific Name: Neritina sp. Origin: East Africa Lifespan: 3 years Max Size: 1 inch Food: Frozen, Algae and Detritus Shipping Size: Approx. 1/2 inch