Nerite snail

Quick facts

Adult size

2.5 cm

Lifespan

can live up to 2 years

Tank zone

all

Temperament

peaceful

Difficulty

beginner

Typically wild-caught

yes - acclimate slowly

Water parameters

Temperature

22–28°C

pH

7.0 to 8.5

Hardness

6 to 20 dGH

Tank requirements

Minimum volume

19 L

Minimum length

30 cm

Flow

low

Lighting

dim preferred

Substrate

any

Lid

required - jumper

Feeding

Diet: herbivore, feeds primarily at the all.

Primarily algae grazers. They rasp hard algae off glass, rocks, and plant leaves using a toothed radula. In a tank with limited algae growth, supplement with algae wafers. They also eat biofilm on driftwood and decaying plant matter. Do not rely on nerites as the sole algae control; a single nerite can keep a 60 L tank's glass clean, but they won't prevent algae problems caused by excess light or nutrients. They graze constantly and slowly, working a systematic path across surfaces.

Vegetable matter required (algae wafers, blanched zucchini, spinach).

Nocturnal feeder; drop food after lights out so it can eat without competition.

Compatibility

• Safe with everything. No fish or shrimp is threatened by a nerite snail.
• Assassin snails will kill nerites. Do not keep together.
• Loaches (clown loach, yoyo loach) and puffers eat snails. Nerites are not exempt.
• Nerites sometimes climb out of the tank. A lid with minimal gaps is recommended. Finding a nerite on the floor is a common experience.

Habitat

Multiple species are sold under the name "nerite snail," most commonly Neritina natalensis (zebra nerite), Clithon corona (horned nerite), and Vittina semiconica (olive nerite). Native to coastal and brackish habitats across Africa, Southeast Asia, and the Pacific islands. They are the most popular algae-eating snail in the hobby because they eat hard green spot algae and diatoms that other snails and shrimp ignore. Shell patterns are distinctive and varied: stripes, spots, horns, and solid colors. Adults reach 2–3 cm depending on species. Unlike pest snails, nerites don't reproduce in freshwater.

Breeding

Cannot reproduce in freshwater. Females lay small white eggs (hard, sesame-seed-sized) on hard surfaces: glass, wood, rocks, equipment, and other snails' shells. The eggs are extremely difficult to remove and do not hatch in freshwater. They are purely cosmetic annoyance. Actual reproduction requires brackish water, and raising larvae through the planktonic veliger stage is difficult. This non-breeding trait is why nerites are popular: they clean algae without creating a population explosion like pest snails do.

Common problems

Egg deposits on decor and glass. Nerites lay infertile eggs on everything and they're cemented in place. A razor blade removes them from glass; on wood and rock you're mostly stuck with them. Shell erosion in soft acidic water: nerite shells dissolve slowly in water below pH 7.0 or KH below 3. The shell thins, pits, and eventually the snail dies. Maintain at least moderate hardness. New nerites sometimes flip over and can't right themselves; place them right-side-up if you find one on its back. Some nerites refuse to eat in a new tank and slowly starve; there's no reliable fix other than ensuring the tank has ample algae growth.

Bioload

Bioload coefficient: 0.2 (snail; minor waste output).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• Stocking ideas by tank size