How Many Nerite Snails Per Gallon? The Answer & Basic Care Guide

    nerite snail

    How Many Nerite Snails Per Gallon?

    Nerite Snails (Neritina) are small snails that like to eat a lot of algae and thus can keep freshwater tanks clean. So the question is, how many Nerite Snails per gallon?

    This species is endemic to the coast of East Africa – Kenya, South Africa, Tanzania, Somalia, or Mozambique. They belong to the family of Neritidae. Also known as the tiger or zebra snails, these cute little beings are very efficient aquarium cleaners and thus very popular in the aquarium trade.

    You do not have to worry too much about their behavior since they are some peaceful, cute little beings, ideal for beginners starting with their first aquarium. They do not have any special demands and are easy to care for.

    They are easy to breed and can multiply quickly, so be careful. Even though they’re so small, you shouldn’t add too many of them to a tank. They produce waste just like any other fish. Overstocking the aquarium with them will add to the bio-load of the aquatic environment.

    To be more exact, here’s a breakdown of how many nerite snails per gallon you should keep in your aquarium.

    Aquarium capacity in gallons


    Ideal Nerite Snails Count


    5 1
    10 2
    15 3
    20 4
    40 8
    50+ 10+


    So, yes, 4 nerite snails for a 20-gallon tank is more than enough. They vacuum the aquarium of algae and also thrive if matched with the right tank mates.

    Let’s go more in-depth about all the implications of keeping nerite snails in your aquarium, from what they eat to lifespan, breeding, tank mates and tank conditions, behavior, and so on.

    What Do Nerite Snails Eat?

    Nerite Snail Sizes
    Photo Credit: Vincent Parsons (Flickr)

    Well, their favorite “meal” is the algae that usually forms on the tank’s surfaces. If you’ve got a well-stocked aquarium, and the algae are growing fast enough, they should be able to live off it alone.

    Moreover, you could try feeding them with algae wafers that are dried and treated algae that will settle on the bottom of the tank. The nerite snails are slow, but they can glide easily over surfaces, decorations, filter intakes, or plants. Their bodies are equipped with sensory tentacles and radula so that they can scavenge for food. Nevertheless, it might take them some time until they come across the algae wafers at the bottom of the tank.

    There are other food options also. Spinach and lettuce can help with a nerite snail’s diet. Yes, we’re talking about the very veggies that you keep in your kitchen. You can add a little of them to the tank.

    However, if you can scratch algae from the aquarium walls, then it means they are fine and have plenty to eat. Don’t overfeed them. Again, if you see them eating off the glass for hours, it means they like the algae, and they’re happy.

    They usually like soft film algae, soft green and brown algae, and also brown diatoms.

    Nerite Snails Lifespan

    The Nerite Snails Lifespan is around one year. Some batches of nerite snails can live up to 2 years if they’ve been together, relaxed, well-cared-for.

    If they’ve been stressed during transportation or if the water parameters are very different from one aquarium to another, they can die within a week of being added to the tank.

    This is why it is very important to ask for a sample of the water the snail is used to and test it for pH, Ammonia, Hardness, and Nitrates. If these parameters are very much different from your tank, then do not add them.

    Yes, they’re so small and cute, and you may feel sad when they die. We understand, but please remove them from the tank right away. A decomposing nerite snail can cause the Ammonia in the tank to rise to dangerous heights for the whole aquarium environment. You will usually find them motionless, on the bottom of the tank, sometimes upside down. If you see them like that, know that something’s wrong.

    However, there could be other reasons why your nerite snail is not moving – click here for more details.

    Difference Between Male and Female Nerite Snails

    It is very tricky to tell the difference between male and female nerite snails. It is almost impossible. They behave, move, and look almost the same irrespective of their gender.

    They all have hard, coiled shells that protect a muscular foot they use to push themselves forward. Their bodies are also equipped with four sensitive tentacles that help them move easily around surfaces and find their food.

    If they’re happy and in good form, both males and females will grow to about 1 inch. Depending on the different species, the coloring and markings on their shells differ.

    Nerite Snail Species

    Zebra Nerite Snail
    Zebra Nerite Snail. Photo Credit: James St. John (Flickr)

    There are hundreds of different nerite snail species. We won’t name all of them, but we can easily single out 4 main snail species:

    • The Zebra Nerite Snails: their shells have black and yellow stripes, and that’s how they’ve got their “zebra” naming.
    • The Tiger Nerite Snails: they’ve also got stripes, only that, compared to the Zebras, their shells are more orange with more jagged stripes.
    • The Olive Nerite Snails: they do not have a specific pattern on their shells but their color gives away their name
    • The Horned Nerite Snails: they also possess black and yellow stripes, but with one tiny addition that gives their name – along one stripe, you will notice a pair of “dark horns.”

    Nerite Snail Reproduction

    You’ll find that most of the information on the Nerite Snails reproduction is quite contradictory. In one place, you’ll read that the snails breed easily; in other places, you might read that it is difficult to breed them.

    Both are true. If you have male and female nerite snails in your aquarium, then they’ll breed and lay eggs all over, no matter if it is a salt or freshwater tank. However, the baby snails won’t hatch unless you have a brackish water tank.

    Keep in mind that nerite snails are not asexual. If you buy them specifically for breeding, you will need both females and males. Sometimes, it might happen to breed nerite snails by accident, but do not expect it to work.

    If you want to do it on purpose, you need to move at least one female and one male in a brackish water tank with gravity between 1.005 and 1.010. The snails will mate, and the female will start laying small clusters of eggs on the glass and the décor of the tank.

    The eggs will then hatch into cute swimming larvae. They’ll be very small, so make sure you use a sponge filter. The larvae will start to develop their shells and, in the end, will cease their swimming habits and switch to crawling over like snails.

    Pay Attention to Imposters

    If you are a passionate aquarist, you will not have a hard time telling the difference between Nerite Snails and other types of snails. However, if you are a beginner, the species you will probably confuse them with are the Mystery snails.

    The Mystery snails have a distinct spiral to their shells, and a more flamboyant antenna, while the Nerites don’t. Moreover, they change gender over time, while the nerites are just one gender from the time they hatch.

    As we have described above, there four big categories of Nerite Snails: the Zebras, the Tigers, the Olive, and the Horned, and they have quite distinct visual characteristics.

    Nerite Snail Tank Mates

    Nerite Snail Tank Mates
    Guppies are great nerite snail tank mates!

    Nerite Snails have no idea what aggression is. They could even teach Nelson Mandela about peace. They like to munch on their algae all day and would appreciate the company of other peaceful fish, shrimp, or other snails.

    Any being that is small and does not want to turn the poor snails into dinner is a perfect tank mate. Aggressive big fish might bite their antennas off or seek to bite out as much as they can from the poor shelled-things and thus gravely hurt them.

    Fish like the Botia Loaches are real snail hunters. They will hunt them down, pull them out of their shells, and eat them. So keep them out of the tank.

    Tetras, guppies, and barbs are good choices for tank mates. Ghost shrimp communities and even other Nerite species are also well-welcomed.

    A mixture of fish and shrimp is maybe the most satisfying mix for you to see so many different appearances and behaviors, and they get along well together.

    If you want a tank full only with Nerite Snails, you can do that. Most Nerites can be kept together with no issues. Well, there is one issue – overstocking. Make sure you keep the ratio of 2 snails per 10 gallons of water.

    If you add too many of them in a small space, they literally won’t have enough algae for dinner.

    Nerite Snail Preferred Habitat and Tank Conditions

    Nerite Snails can easily adapt to a wide range of water conditions. Since they’re endemic to the coast of Africa, they like tropical water temperatures of around 72-78°F. The proper pH is 8.1 -8.4, and the salinity, in case you’re building a marine habitat, shouldn’t be higher than 1.028sg.

    In their natural habitat, they live in mangroves and estuaries with a lot of rocks and other surfaces where they gather their algae. If you can replicate some sort of environment to resemble that in your water tank, then they’ll love it.

    In saltwater, they’ll appreciate hiding spots. Live rock would be a good idea. The Nerite Snails’ tentacles are quite sensitive, so make sure you provide them with a fine grain, sandy bottom that will not bring damage to them.

    Calcium substrate will be like shooting two birds with one stone: it is soft and will also provide the much-needed supply of calcium that the snails need for a strong, healthy shell.

    You can also keep them in freshwater habitats. The conditions are mostly the same. Add some rocks and driftwood. Make sure you create plenty of hiding spots for the snails and also provide them with a fine-grained substrate.

    You can use plants without any issues, for the snails won’t eat them. Java fern is a good idea, for it grows at a slow rate.

    The Nerite snails living in natural freshwater habitats will climb above the surface of the water at night, once the water levels change with the tide. You might want to recreate these conditions by lowering the levels of the water in the tank and leaving them the possibility to get out of the water for a brief moment.

    Make sure the water is free of ammonia and that the nitrate levels are not more than 20mg/L. So, if you purchase a proper filter and heater, keeping these water conditions shouldn’t be a biggie.

    Knowing how many nerite snails per gallon really helps with maintaining the ideal tank conditions.

    Nerite Snail Care

    Here is a short/informative video on a basic care guide for nerite snails:

    Snails can suffer from a variety of health problems. You can avoid some of them through proper care.

    One of the main causes for concern is the snail’s shell. Sometimes, their shells just don’t grow big enough. This happens if the water temperature is too low or if they don’t have enough food.

    If they eat too much, then their shells will discolor. In the wild, most Nerite Snails’ shells are dark in color, for they do not have as much food as in an aquarium.

    If the snails do not have calcium, then their shells can become weak and crack. If you notice little cracks on their shells, you should add calcium sulfate or use a calcium substrate in the aquarium.

    The shell is telling us a lot about a nerite snail’s health. For example, if you notice white spots on the shell, they are probably latched-on parasites. This does not necessarily mean the snails have also been affected by internal parasites.

    However, both external and internal parasites can prove fatal to a Nerite snail’s health.

    Old snails usually fall ill with a disease called “Oedema.” As a consequence, their body will begin to swell and fill with fluid making it hard for them to move around seeking food.

    One major thing you should keep in mind is copper. Avoid it, for it is toxic for the snails. It is toxic for most invertebrates. Do not use tank decorations that contain copper. Do not give them food or medications that contain copper. Read the labels twice to make sure they do not get in contact with copper.

    Conclusion – How Many Nerite Snails Per Gallon?

    So, how many nerite snails per gallon is ideal? 1 per 5 gallons is the final answer. Multiply from there!

    As you have seen, overstocking can be a serious problem since they produce waste like any other aquatic being and need the algae in the water tank to survive.

    Overall, the nerite snails are pretty easy to keep and care for. They’re peaceful little beings and enjoy the company of other small peaceful fish, shrimps, and other snails. They will vacuum clean your tank of algae, but keep an eye on them for parasites and other health issues.


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