Zebra Nerite Snail

The Zebra Nerite Snail (Neritina natalensis) is the gold-standard natural glass cleaner against stubborn Green Spot Algae (GSA) and brown diatoms. Unlike pest ramshorn or bladder snails, Nerites never touch living aquatic plants and cannot overpopulate freshwater tanks because their eggs require brackish water to hatch.

Zebra Nerites need neutral to alkaline, moderately hard water (pH 7.0–8.5, GH 8–18 °dGH) to maintain their striped calcified shells without pitting or erosion. Acidic water below pH 6.8 slowly dissolves the shell periostracum. Check upright posture occasionally—if a Nerite falls upside-down on soft sand with nothing to grip, right it by hand—and keep a lid on the tank as they occasionally explore above the waterline.

Strict herbivorous biofilm and algae grazer: its toothed radula scrapes hard spot algae (GSA) and diatom films off glass, rocks, and wood while leaving living plants untouched. Introduce only into matured aquariums (3–4+ weeks old) at 1 snail per 15–20 liters so natural algae growth sustains them.

Gonochoristic (separate sexes). Females occasionally deposit small white sesame-seed-like egg capsules on driftwood or rocks, but the veliger larvae require brackish estuary water to develop—so zero snails ever hatch in freshwater aquariums.