Could a small snail tackle algae without filling your aquarium with more snails? Horned nerites graze on algae growing on tank surfaces, and although they may lay eggs, those eggs do not hatch in ordinary freshwater conditions. Good horned nerite snail care means looking beyond their reputation as a clean-up crew: a spotless tank may leave them short of food, while unsuitable water can damage their shells.
This guide covers the tank size and water conditions horned nerites need, how many to keep, what to feed when algae runs low, which tank mates are safe and how to settle new snails in.
Key Takeaways
- Horned nerites stay small, at about 1 to 2 cm, and suit tanks from 20 litres upwards.
- Keep the water at 22 to 27°C with a pH of 7.0 or above and moderate hardness to protect their shells.
- They graze soft algae and biofilm, so add algae wafers or blanched vegetables when algae runs low.
- Their eggs do not hatch in fresh water, so they will not overrun your tank, but the small white eggs can mark wood and rocks.
- Fit a tight lid, avoid copper-based medicines and keep them away from snail-eating fish.
What Do Horned Nerite Snails Need in an Aquarium?
Horned nerites (Clithon corona) come from coastal streams and estuaries in South East Asia. In the aquarium they spend their days slowly grazing glass, rocks, wood and plant leaves. They need a mature tank with some algae, stable water and enough minerals to keep their spiky shells strong.
Tank size and water conditions
A single horned nerite can live in a tank of 20 litres, and larger tanks can hold more. Only add them to a fully cycled aquarium, as they are sensitive to ammonia and nitrite. Soft, acidic water slowly dissolves their shells, so keep the pH at 7.0 or above and the water moderately hard.
| Parameter | Target for horned nerites |
|---|---|
| Tank size | 20 litres or more |
| Temperature | 22 to 27°C |
| pH | 7.0 to 8.0 |
| Hardness | Moderately hard |
| Adult size | About 1 to 2 cm |
| Lifespan | Around 1 to 2 years, sometimes longer |
How many horned nerites should you keep?
As a rough guide, allow one horned nerite for every 10 to 20 litres, depending on how much algae your tank grows. Too many snails in a clean tank will run out of food quickly. They are not social, so one on its own is fine.
How to Set Up a Tank for Horned Nerites
Horned nerites are easy to house once a few basics are in place.
Surfaces to graze
Rocks, driftwood and broad-leaved plants such as Anubias give them plenty of surfaces where algae and biofilm can grow. A tank that is cleaned until spotless leaves little for them to eat, so leave some algae on the back and side glass.
A tight lid and safe equipment
Nerites often climb above the waterline and can leave the tank, so fit a tight lid and cover any gaps around pipes. Cover filter intakes with a sponge, and check on any snail that sits out of the water for long periods, as this can signal poor water quality.
What Do Horned Nerite Snails Eat?
Horned nerites graze soft green algae, diatoms and biofilm. They do a good job on glass, rocks and leaves, but they cannot remove tough algae such as black beard algae.
When algae runs low, feed sinking algae wafers or blanched courgette, cucumber or spinach two or three times a week. Remove uneaten vegetables within 24 hours. A calcium source, such as a cuttlebone in the filter or a mineral supplement, helps keep shells healthy in softer water.
How to tell they are healthy
A healthy nerite moves steadily, grips surfaces firmly and has a smooth, glossy shell with intact spines. Pitting, white patches or a snail that stays closed up or falls onto its back for long periods suggest low minerals or a water quality problem, so test the water straight away.
Tank Mates for Horned Nerites
Horned nerites are peaceful and suit most calm community tanks, but some fish and invertebrates see snails as food.
| Tank mate | Suitable? | Notes |
|---|---|---|
| Small community fish | Yes | Tetras, rasboras and livebearers ignore them |
| Shrimp | Yes | Share the clean-up work peacefully |
| Other snails | Yes | Mystery and other nerite snails mix well |
| Assassin snails | Yes, with care | May attack small or weak nerites |
| Loaches and pufferfish | No | Will hunt and eat snails |
| Large cichlids | No | May pick at or crush them |
A simple rule: if a fish is not known to eat snails, it is likely to be fine with horned nerites.
Bringing Your Horned Nerites Home
Float the bag to match the temperature, then add small amounts of tank water over 30 to 45 minutes. Place each snail upright on a rock or the substrate rather than dropping it in, as some struggle to turn themselves over. New nerites may stay still for a day or two before they start grazing.
About their eggs
Females may lay small white eggs on wood, rocks and glass. These need brackish water to develop, so they will not hatch in a freshwater tank. They do not harm anything and can be scraped off if you dislike how they look.
Give Your Horned Nerites a Settled Home
With a mature tank, hard-leaning water, enough algae or supplementary food and a secure lid, horned nerites are hardy, useful and full of character. Keep the numbers sensible for your tank and they will keep surfaces clean without ever taking over.
For more on aquarium snails, read our guide to freshwater snail myths and our guide to lava snail care, or browse aquarium snails for sale.
Frequently Asked Questions
Do horned nerite snails breed in freshwater?
They may lay eggs, but the eggs need brackish water to develop, so they do not hatch in a freshwater aquarium and the snails will not overrun your tank.
What do horned nerite snails eat?
They graze soft algae, diatoms and biofilm. Add sinking algae wafers or blanched vegetables when the tank runs short of algae.
How many horned nerites can I keep?
Allow roughly one snail for every 10 to 20 litres, depending on how much algae your tank grows.
Why is my horned nerite snail out of the water?
Nerites sometimes climb above the waterline, but doing it often can be a sign of poor water quality. Test the water and keep a tight lid on the tank.
Are horned nerites safe with shrimp?
Yes. They are peaceful and share the tank with shrimp without any problems.
Why is my nerite snail shell turning white?
White patches or pitting usually mean the water is too soft or acidic. Keep the pH at 7.0 or above and add a calcium source.
What temperature do horned nerite snails need?
Keep them at 22 to 27°C in a heated tropical aquarium and avoid sudden temperature changes.