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

    View of the two snails Ampularia a home freshwater aquarium

    How Many Mystery Snails Per Gallon?

    how many mystery snails per gallon

    Mystery Snails (Pomacea bridgessi) are a South American species of freshwater snails. Just like nerite snails, they clean the tank of algae. If you want to keep your freshwater tank as clean from algae as possible, you should have some mystery snails in your tank. The question is: how many mystery snails per gallon should you keep?

    The short answer is that you should keep as many as 1-2 mystery snails per 5 gallons. If you have a tank larger than 5 gallons, just divide the aquarium capacity in gallons number by 5 (example: 20 gallon tank ÷ 5 = 4). Then, multiply that result by 2 to get the max number of mystery snails you can keep in your tank. 

    Here’s a breakdown of how many mystery snails you should keep per gallon of water.

    Aquarium capacity in gallons


    Ideal Mystery Snails Count


    5 1-2
    10 2-4
    20 4-8
    30 6-12
    40 8-16
    50+ 10+

    Let let us tell you a few more interesting things about the Mystery Snails. For example, did you know that they are born with gills and lungs? They have a small tube to breathe air through and usually surface to the top of the water to breathe.

    More than that, they can completely regenerate their eye if it has been damaged. How cool is that?

    They can reproduce quite quickly. They lay eggs and after 2-4 weeks, the eggs hatch. It is not uncommon for them to make as many as two hundred offsprings in one egg-laying event. That’s a lot, so that’s why it’s necessary to know how many mystery snails per gallon to keep so they can be happy and thrive.

    Mystery snails can easily become one of your favorite freshwater beings. They’re so little, adorable, and fun, and caring for them won’t create too many issues. More than that, they’ll help keep your aquarium clean by eating all the algae. So, why wouldn’t you love them?

    Let’s learn more about them and how to properly tend to them.

    What Do Mystery Snails Eat?

    In the wild, mystery snails eat all sorts of plants, even dead and rotting. In captivity, the aquarium algae will become their favorite food.

    They usually go searching for food, and once they find a source of vegetation, they’ll start devouring it. So your job will be to make sure the aquarium never runs out of algae.

    Algae is the fundamental food source for mystery snails. Naturally occurring algae is even better. To keep growing algae in your aquarium, you first have to make sure there are enough smooth surfaces in there.

    However, if you struggle with this, you can also use algae wafers or sinking pellets. It will help supplement their diet and keep them thriving.

    General veggies you have in the kitchen are also a good food option for mystery snails. You can feed them a little bit of cucumber, some zucchini or spinach, or even kale. They won’t object.

    However, you do need to keep an eye on the impact these can have on the water quality in the aquarium.

    How Often To Feed Mystery Snails

    How Often To Feed Mystery Snails

    People wondering how often to feed mystery snails need not worry. You don’t feed mystery snails too often. If you have enough naturally-growing algae in your aquarium, they’ll be happy. They’ll just suck onto the glass of the tank and eat the algae sticking on it.

    They’ll keep at it until it’s clean and then move on to find other sources of vegetation and so on. You’ll love them for that, for in their food-finding process, they also keep your aquarium clean.

    When you clean the tank glass by hand, take a closer look at it, and you’ll see some tiny tracks the snails have left as they moved along. Their little bodies come equipped with a radula, which is an anatomical structure common to most mollusks and resembles a tongue.

    The radula has some minuscule teeth on it, and using these tiny teeth, the mystery snails scrape the algae from the glass. It’s quite fascinating. If you have some time, look closer at the way they’re doing it.

    As for the mystery snails diet, you could also help them grow shiny and strong shells by giving them calcium supplements, feeder tablets, or flakes.

    You can give them calcium in different ways. One way is to use wonder shells. You can also add crushed coral to the water. Cuttlebone is also a solution. You put it in the tank, and it sinks. The snails will come chewing on it, and thus they get their much-needed calcium.

    Again, we repeat the same warning, do not let any of this additional nourishment sit too much in the tank. It will damage the water quality and further create health problems for the little fellas in there.  

    Mystery Snail Lifespan

    The average mystery snail lifespan is a year. With great care and food, you can extend their lifespan to a bit more than that. However, in the same way, if you do not care for them properly, do not give them the calcium and nourishment they need, they can live even less than that.

     Difference Between Male And Female Mystery Snails

    We have a detailed post on how to tell the difference between male and female mystery snails; click here to check it out. 

    One obvious way to tell the difference is to see them mate and lay eggs.

    An interesting thing to note is that mystery snails can change gender. However, why this happens and at what frequency is still not certain. 

    How Often Do Mystery Snails Lay Eggs?

    How Often Do Mystery Snails Lay Eggs?

    Mystery snails lay eggs once a week, but they can have episodes of 2-3 months when they do not lay eggs at all.

    A female mystery snail lays at least 4 groups of eggs. That is about 400 eggs. Out of these, only about 30 will hatch after 2-4 weeks.

    The mystery snail breeding process is quite simple. You need a female and a male in a tank. You don’t need to operate any changes to the tank’s water parameters for the mating process.

    The female will simply lay the eggs near water the surface. You will notice some sort of irregular cocoon where the eggs are placed. If you do not want to breed them, then you can easily remove the eggs from the tank.

    It takes a mystery snail egg about 2 to 4 weeks to hatch. The air around the cocoon should be pretty humid for the eggs to hatch. Once they do, there’s no need to move the baby snails to another tank or tinker with the water parameters.

    They will be fine. They’ll get down to the bottom of the tank and start feeding on the same food as their parents.

    To help the mystery snails breed, try lowering the water level a bit so females have room to lay the eggs.

    We will repeat this. The mystery snail female will lay eggs close to the surface. So, do not make the mistake of thinking you need to toss the eggs in the water to survive. You will kill them this way. Let them hatch on the surface where the mother has placed them! She knows what she’s doing.

    Mystery Snail Tank Mates

    The best mystery snail tank mates should be peaceful. More than that, they shouldn’t be big enough to consider the snails their dinner.

    Mystery snails make for “quiet neighbors”. They don’t care much about any other aquatic beings. They will just mind their own business.

    Some good mystery snail tank mate choices are Tetras, Guppies, Ghost, Cherry or Amano Shrimp, Blue Velvet, Snowball or Blue Tiger Shrimp, and other species of snails, including Nerite Snails.  

    Mystery snails will also get along well with Killifish, Cory Catfish, or Otocinclus. In general, avoid fish that like to eat snails, like Oscars, Cichlids, or Crayfish.

    Mystery Snail Preferred Habitat and Tank Conditions

    Mystery Snails’ natural habitat is endemic to Paraguay, Brazil, or Bolivia. However, they have also spread to other parts of the world. In the wild, they live in rivers, ponds, and swamps. Their main diet is composed of dead plants. They only eat live plants when they do not find other available food sources.

    Nevertheless, Mystery Snails can thrive in a wide range of water conditions. If there’s one thing they don’t like is instability and sudden changes. So avoid to do drastic water parameter changes for it will stress them out.

    You should establish the tank before you bring the snails in. Cycle it before and make sure it is ready to receive the new community. Do not go over the top. Establish a moderate, clear, oxygen-rich water tank.

    Mystery snails usually like the murky waters, but if you want to have a clear view of them, they won’t object to clear water tanks either.

    In general, keep a pH of 7.0-8.4. The water temperature should be between 68 – 82 Degrees Fahrenheit (20 – 28 С). A normal community tank lighting is enough.

    If possible, keep the pH levels a little high. Low pH could contribute to dissolving the snails’ calcium carbonate shells.

    One interesting thing about the Mystery Snails is that they can survive even in low-temperature waters of about 10°C. At these levels, they will simply go into some sort of hibernation mode.

    The most important thing is to eliminate Ammonia and Nitrites. They should be 0. This might pose a bit of a challenge since most plant fertilizers and tank treatments contain copper.

    Copper is fatal to Mystery Snails, so make sure you read the labels twice before you add anything new to the aquarium.

    Mystery Snails love calcium-rich waters. Their shells are made of 95-99.9% calcium carbonate, so they need calcium to keep strong and shiny. Purchasing a Calcium test kit might be a good idea if you want to grow a large, healthy community of Mystery Snails.

    They will spend most of their time slowly moving around surfaces. So, the more available areas, the better.

    One good suggestion is to keep the tank full of vegetation. Go for Java Fern, Java Moss, and Hornwort. This way they will have plenty of natural food and plenty of surfaces to crawl over.

    Also, consider adding hard substrates. Gravel, sand, and pebbles will give snails something to crawl over, helping them to move around more easily.

    All of these tank conditions really help get the right balance of mystery snails per gallon.

    Mystery Snail Care

    Below is a nice video showing how to take care of mystery snails.

    Mystery Snail care is quite simple and effortless. There are a few things to keep an eye out for, though.

    Mystery Snails can unexpectedly find their way out of the tank. They can die from falling from the tank or simply from drying out. So, it would be a good idea to count them from time to time and keep the tank covered as much as possible.

    Avoid overstocking the tank with mystery snails. Yes, they do a great job cleaning the tank, but they also add to the bio-load; they produce waste. So, don’t add them just because they are good cleaners. You should also care for their needs so that they are part of a sufficiently-large water tank, with plenty of surfaces to cling to.

    As for diseases, mystery snails are usually healthy creatures, not very prone to illnesses. Just like Nerite Snails, they tend to swell up when they get older and will eventually die from the fluid buildup. It is not much you can do for this condition.

    Other than this, pay attention to the calcium levels in their diet and water. They will suffer greatly if they do not receive a fair amount to keep their shells in good shape. If you observe little cracks and pits in their snails, it’s a warning sign that you should amp up their calcium intake.

    Do not try to use any antibiotics to cure snails unless the manufacturer has written on the label that they’re safe for snails. Most antibiotics are not good for any species of snails.

    Why Are Mystery Snails Called Mystery Snails?

    This is mostly a mystery in itself. There are some theories that in the beginning, aquarists had no idea what kind of snails they were, but they knew they could eat algae, so they called them mystery snails.

    We’re sorry, but we don’t have a better explanation than this. It might also have to do with their appearance. They come in many different colors such as gold, blue, orange, dark greenish, black, purple, white, ivory, or brown. Their shells also have a large variety of patterns, so you can’t pin them down.

    Conclusion – How Many Mystery Snails Per Gallon?

    We hope we have answered your question on How Many Mystery Snails per Gallon you should keep and maintained your interest in this wonderful species.

    Yes, it’s quite a mystery why they’re called mystery snails, but it’s no mystery that they’re really good tank cleaners and that you shouldn’t keep more than 2 per 5 gallons.


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