Quick Stats
| Adult Size | 2–2.5 cm |
| Minimum Tank | 5 gal |
| Temperature | 20–27°C |
| pH Range | 7.0–8.0 |
| Hardness (GH) | 8–18 dGH |
| Difficulty | Easy |
| Temperament | Peaceful algae grazer |
| Diet | Herbivore — algae, biofilm on glass, driftwood, and rocks |
| Schooling | 2–4 per 10 gallons as a clean-up crew |
Tank Setup
"Nerite snail (Neritina spp.)" is a trade name covering a cluster of small neritid species from tropical coastlines worldwide — the classic zebra nerite is Vittina natalensis (formerly sold as Neritina natalensis) from East Africa, joined in the hobby by tiger nerites, olive nerites, red racers, and the horned Clithon species. All share the traits that made the group famous: voracious algae and biofilm grazing, attractive shells, and a hard-coded migratory need to return to brackish water to breed — which is why, wonderfully, they cannot overrun a freshwater tank.
Their requirements are short. Temperature 20–27°C, pH 7.0–8.0, and — the one that matters — hardness 8–18 dGH with real calcium: nerites build thick shells and need mineral water to maintain them, and soft, acidic water slowly dissolves and pits their shells the way it never touches a ramshorn's. A 5-gallon tank comfortably houses a small cleanup crew of two; scale 2–4 snails per 10 gallons. Any filter works; they are indifferent to flow.
Two pieces of equipment genuinely matter: a lid (nerites are escape artists that cruise above the waterline at night, and an open-top tank means a dried snail on the floor eventually), and smooth decor without copper exposure (snails are copper-sensitive — check any medication and fertilizer). Acclimate them slowly — most trade stock is brackish-collected, and a fast dump into freshwater is the commonest way new nerites die. The hardness guide covers getting your GH into the right band.
Tank Mates
Nerites are model invertebrate citizens: too slow and too armoured to bother anything, and defenceless against anything that decides to bother them. Their tank mate list is decided entirely by predator screening.
Compatible with everything peaceful: all community tetras, livebearers, bettas (usually — see below), corys, gouramis, and the entire shrimp and snail crew — cherry shrimp, Amano shrimp, mystery snails without conflict. They eat algae and biofilm, so they compete with nothing for fish food.
The avoid list is the snail-predator list: pea puffers (snail specialists — a nerite is a banquet), assassin snails, crayfish, and big cichlids that crunch shells; loaches that cannot crack a nerite's shell (clown loaches (Chromobotia macracanthus) mostly) will still stress them with constant harassment attempts. Bettas (Betta splendens) are a coin-toss: most ignore snails entirely, but some individuals nip at antennae persistently. Cracked-shell incidents mean rehoming the snail or the fish, not waiting it out.
Diet & Feeding
Nerites are the hobby's best algae-grazing snails — they work glass, smooth decor, and plant leaves continuously, and they genuinely suppress soft algae films, brown diatom dust (see the brown algae guide), and the early stages of hair algae on smooth surfaces. They do not eat rooted plants — your greenery is safe. They also do not eat the tough black beard algae tufts, whatever the shop label implied.
Supplement when algae run low: blanched zucchini or spinach, algae wafers, and calcium-rich offerings keep a clean tank's nerite crew fed and their shells thick. A starved nerite grazes the same rocks to a polish and then quietly fails — the warning sign is a snail that stops moving for days with its operculum sealed.
Population math is where nerites shine: two to four per ten gallons clean hard, and they cannot breed beyond that number in freshwater. The famous white "sesame seed" egg capsules females lay on glass, driftwood, and hardscape are harmless, unfertilisable duds in freshwater (larvae need brackish water to develop) — they will not hatch, they just need a razor blade or patience to remove.
Common Health Issues
Nerite health is shell health and acclimation health. Shell problems come from soft, acidic water: pitting, whitening, thinning, and eventually cracking. Keep pH above 7.0 and GH above 8, feed calcium-bearing supplements, and shells stay thick; the water parameters guide covers the full mineral story. A rough, dissolving shell is a chemistry alarm, not a snail defect.
Acclimation failure is the other killer: new nerites arriving from brackish holding systems are osmotically fragile. Drip acclimate over an hour or more (the acclimation walkthrough applies), and expect a settling period where some lie sealed for a day or two — an operculum that resists a gentle tug means a live snail; a smell means you lost one.
Escape and copper round out the list: a lid prevents the dried-snail-on-the-floor story, and any copper-containing medication or plant treatment kills all invertebrates in the tank (treat the fish in a hospital tank instead — our disease guide assumes livestock separation for a reason). Well-kept nerites work the glass for years — they are among the longest-lived aquarium snails.
Breeding
Nerites do not breed in freshwater — full stop, for every species in the trade. Their life cycle is amphidromous: adults live in freshwater but larvae must develop in brackish or marine water before returning upstream. In your home aquarium, females still lay the small white egg capsules on hard surfaces (the "sesame seeds"), but the larvae never develop, and no population ever establishes. This is the species group's defining advantage over every other algae snail.
Raising nerites deliberately requires brackish larval rearing — marine-ish water, microalgae, and careful salinity — which is why essentially all trade stock is wild-collected from brackish coastlines and why home breeding is a specialist project rather than a casual outcome.
If the white egg capsules bother you aesthetically: they scrape off glass with a razor blade, soften and fade over months, and only females lay them — but sexing live nerites is unreliable, so population-level avoidance means keeping one snail per tank and accepting slightly less cleaning capacity.
Frequently Asked Questions
Will nerite snails breed and overrun my tank?
No — and this is their best feature. Nerite larvae require brackish or marine water to develop, so in a freshwater aquarium the eggs never hatch. Females still lay small white egg capsules ("sesame seeds") on hard surfaces, which are harmless but cosmetically annoying; they can be scraped off. No population explosion is possible in any freshwater tank, which is precisely why nerites are the most-recommended algae snail.
Why is my nerite snail not moving?
Check three things in order. Operculum test: a snail sealed with its trapdoor "lid" that resists a gentle touch is alive and resting (new arrivals do this for a day or two). Position: nerites often park in the same spot for a day; look for the snail having moved at all over several nights. Smell test: a lifted snail that smells bad is dead and should be removed immediately. Also confirm it is not above the waterline — nerites cruise out of the water by design, so check the lid area before assuming an escape was fatal... or forgetting to look there at all.
Do nerite snails need algae wafers?
In a well-algaed tank, no — they graze continuously and stay fat on the natural film. In a clean, mature, low-nutrient tank, yes: algae runs out and nerites starve slowly. Offer blanched vegetables (zucchini, spinach) once or twice weekly and an occasional algae wafer at lights-out. A snail that eats offered food eagerly is fine; a snail that ignores food and stays sealed for days needs attention.
Can nerite snails live with bettas?
Usually, yes. Bettas generally ignore nerites — too big, too armoured, not a fin to nip. A minority of individual bettas nip at snail antennae persistently, which the snail tolerates poorly. Introduce the snail, watch for a week, and if your betta turns out to be that individual, the pairing fails on temperament rather than theory. The combination is one of the most common nano-tank pairings in the hobby, and it mostly works.