Species · Shrimp & snails
Nerite Snail
Neritina spp.
The best algae-eating snail that won't overpopulate your tank — its eggs need brackish water to hatch. Wants harder, alkaline water for a strong shell, and copper-free like all inverts.
Difficulty: BeginnerShrimp / invert tank✓ Fact-checked care guide
Quick facts
| Adult size | ~1.3–3 cm / 0.5–1.5 in (varies by type) |
|---|---|
| Minimum tank | ~20 L / 5 US gal (a great nano and community cleanup animal) |
| Temperature | 22–28 °C / 74–80 °F |
| pH | 7.0–8.5 (slightly alkaline) |
| Hardness | 8–20 dGH — needs harder water and calcium for a strong shell |
| Filtration & flow | Any cycled tank; keep a lid (nerites can wander above the waterline) |
| Diet | Algae grazer — green spot algae and diatoms; supplement with algae wafers if the tank is clean |
| Social | Keep singly or in a group — non-social but happy together |
| Temperament | Completely peaceful |
| Lifespan | 1–2 years (sometimes longer) |
Overview
The nerite snail (Neritina spp.) is widely rated the best algae-eating snail in the hobby — it grazes stubborn green spot algae and diatoms off glass, wood and leaves without touching healthy plants.
Its killer feature: it won't overpopulate your tank. Nerites lay eggs in freshwater but the larvae need brackish water to hatch, so — unlike pest snails — you never get a population explosion (just the occasional harmless white egg capsule on hard surfaces).
Water & tank
Nerites want harder, slightly alkaline water — pH 7.0–8.5 and around 8–20 dGH — at 22–28 °C / 74–80 °F, because they need calcium and a stable pH to keep a strong shell. Soft, acidic water pits and erodes the shell.
They fit any cycled tank down to a nano. Keep a lid, as they wander above the waterline. And, as with all inverts: no copper.
Feeding
A dedicated algae grazer — in a mature tank the algae and biofilm often feed it. In a very clean tank, supplement with algae wafers so it doesn't starve.
Behaviour & tankmates
Peaceful and safe with plants, shrimp and fish. Great in a community or shrimp tank as a clean-up crew.
Avoid known snail-eaters (some loaches, pufferfish) and, of course, copper.
What to expect
A quiet, efficient glass-and-wood cleaner. Small white sesame-seed egg capsules on hard surfaces are normal and harmless — they won't hatch in freshwater (you can scrape them off if you dislike the look).
Myths, kindly busted
“Nerite snails will breed and infest my tank like pond snails.”
They cannot — their larvae need brackish water, so they never overpopulate a freshwater tank (they only leave harmless unhatched white eggs).
“Snails do fine in any water.”
Nerites need harder, alkaline water with calcium for a healthy shell — soft, acidic water erodes it.
When to act
We triage, not diagnose — but these are worth a closer look (starting with a water test):
- A pitted, thinning, or cracking shell — usually water too soft/acidic or lacking calcium; raise GH/KH and add a calcium source.
- A snail that stays sealed up and inactive for a long time, or smells foul (dead) — check water quality (and for copper).
Sources & further reading
- Aquarium Co-Op — Nerite Snail care — Adult ~0.5–1.5 in; temperature 74–80 °F / 22–28 °C; pH ~7–8.5; GH 8–20 (calcium for shell); top algae eater; eggs need brackish to hatch (won't overpopulate freshwater); copper toxic.
Written & fact-checked by The Finfern Team against the sources above — kind, general guidance, not a diagnosis. If something looks wrong, test your water and, if it persists, contact a fish-savvy vet.
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