AQUATIC PLANTS & LIVESTOCK

Nerite Snail

Algae-eating snail that cannot breed in freshwater — no population explosion.

Stocking stage Plants

Unplug before servicingHands out of the water firstDrip loop on every cableTest before you dose30 ppm CO₂ ceilingCycle before stocking

Plants

Specification
Adult size	2–3 cm
Water	Neutral to hard, alkaline
Temperature	22–28 °C
Breeding	Not possible in freshwater
Lifespan	2–4 years
Diet	Algae, biofilm

Technical parameters
pH range	7.0–8.4
GH	6–15 dGH
KH	4–10 dKH — required for shell
Stocking	1 per 15–20 L
Egg capsules	Laid but never hatch
Escape risk	High in open tanks

Nerite snails are the answer to the algae problem that most snails create. They graze diatom films and green spot algae off glass, stone and leaves, they are completely plant-safe, and they cannot reproduce in freshwater — their larvae need brackish water to develop. A tank with six nerites in it will still have six nerites in it a year later.

That single trait makes them uniquely useful. Malaysian trumpet snails and ramshorns breed to the carrying capacity of the tank and become a nuisance; nerites simply work. They are also long-lived, reaching several years, and their shells — striped, horned or zebra-patterned — are attractive in their own right.

Two caveats. They lay eggs constantly even though the eggs never hatch, and those small white capsules stick to hardscape and glass and are tedious to remove. And they are escape artists: a nerite will climb out of an open-top rimless tank and be found dead on the floor. A lid, or a waterline well below the rim, is the mitigation.

Safety and welfare

Nerites need carbonate hardness to build shell. In very soft water their shells erode and they die. Test KH and remineralise if needed.
An open-top rimless tank needs a lid or a low waterline. Nerites climb out and desiccate.
Never use copper-based treatments. Snails are as sensitive to copper as shrimp.

Using it well

Two or three nerites will keep a 60 cm tank's glass clear of green spot algae that a scraper struggles with.

If the shell looks pitted or thin, the water is too soft. Add a calcium source rather than more snails.

The white egg capsules are harmless but permanent. Scrape them off hardscape with a blade during maintenance.

Compatible with

Neon tetraCherry shrimpAnubiasJava fernSeiryu stone

Worth knowingPlant-safe and shrimp-safe. One of the few algae eaters that will not touch moss or carpet plants.

Note. Parameters are conventional ranges across the category, not the claim of any one manufacturer. Nothing on this page is for sale and no outcome for any plant or animal is guaranteed. Simulator output elsewhere on this site is a simplified model, not a measurement — confirm everything with a test kit and the equipment's own instructions.

Nerite Snail

Using it well

Compatible with

Works alongside