Why Snails Appear in Fish Tanks

Every fish keeper will get snails into their fish tank. That is a good thing since the snails will help to keep the fish tank clean. But how are they appearing in the fish tank when you haven’t planted them into the aquarium?

In general, you will get snails into your fish tank through the eggs from the snail that is put on plants, substrate, or decor. In the store, the snail the store keeps to keep the plants clean from algae puts its eggs underneath a leaf and when you put that plant into your aquarium, the eggs will hatch into snails.

You could take some measures to be sure that you won’t get an infestation of snails into your fish tank. We will go through everything in this article.

Where Are The Snails In Fish Tanks Coming From?

Snails will usually come from the store where you buy your plants. Other ways snails could get into your fish tank is through the substrate or the decor if you buy it used.

In all these ways you will not get a snail sitting on the plant and get into your fish tank. It’s the eggs that are following the plant, substrate, or decor.

The eggs will then hatch into snails in your fish tank and they start to propagate, usually quite quickly.

In the fish store where you buy your plants, they keep snails in the tanks where they have their plants. That’s because they want to keep the algae away from the plants and the snails are doing a good job to do so.

The algae will grow in the tanks where the store keeps their plants because the light is on for too long for the plants to use all the light. The light the plants don’t use, the algae will use.

If you want to read more about plants and light, I have an article where you will learn all about it if you want to check it out!

The downside is that when the snails thrive, they will reproduce and they do it by putting their eggs everywhere.

One of the places they put their eggs is underneath the leaves and in every crooks and cranny on the plant.

These eggs will follow the plant and home to you when you buy that plant.

Snails could also get in through the decor and substrate, but that is not as common as the way via the plants.

That’s because if you buy decor or substrate in the store, you buy it dry. They are sitting on a shelf where no snails are living to put their eggs on.

The exception is if you buy it used.

The person you buy your decor or substrate from probably had snails who had put their eggs on the decor or in the substrate. And now you are buying it (probably cheap) and putting it into your fish tank.

If you get snails into your fish tank this way, you don’t have a lot of choices of which snail you will get.

To have more control, it’s best to plant it in yourself, which is quite straightforward.

You just buy the snail in the store and put it into your fish tank.

Why Are Aquarium Snails Propagating So Quickly?

Once the snail is in the fish tank, they will reproduce very quickly because they will put a lot of eggs that hatch into snails. If you have just started the fish tank, the snails have a lot of food available which makes them reproduce faster. Some species are also hermaphrodites which means they don’t need a male and a female to reproduce. They can do it by just themselves.

If your snails are reproducing quickly and you feel that it’s starting to get out of control, you probably have too much debris or fish food rests in your fish tank.

If a lot of food is available, the snails will reproduce more. And most snails are made to reproduce quickly.

They put a lot of eggs. Sometimes it could be over 100 eggs that they put everywhere they can. Not all these eggs are hatching into snails but if just 10% hatch, you will have 10 new snails from the eggs just 1 or 2 snails are laying.

It will grow exponentially and the number of snails will grow very quickly and then find a balance between the amount of food for them and the number of snails.

It will be an equilibrium.

Some snails are hermaphrodites which makes them more prone to quickly propagate.

The hermaphrodites don’t need a partner to reproduce. They can do it all by themselves. This could make one snail do a lot of babies.

One snail that is hermaphrodite is the Malaysian Trumpet Snail.

It should be noted that not all snails can reproduce in freshwater. Some need brackish or saltwater to reproduce. These snails are not considered as “problematic” as the ones reproducing in freshwater.

A snail needing brackish water to fully grow into adults is the zebra snail. It will lay eggs that will hatch but the baby won’t grow into an adult without brackish water.

How To Lower The Number Of Snails

To lower the number of snails in your fish tank, the best way is to prevent them from coming into the tank from the beginning. You should not remove them chemically and the easiest way to do it is to limit the amount of food for the snails.

If you don’t want snails in your fish tank, you should prevent them from coming in when planting new plants. Be sure to put in some snails any way because they are very good to keep the fish tank clean.

To prevent snails from coming into your fish tank, don’t buy your substrate or decor used.

The safest way to get your decor and substrate is by buying it from the shelf in a store. You have a very low risk of bringing snails into your fish tank.

It will be a little more expensive. But it could be more expensive in the end if you have to remove the snails coming with used products.

If you buy high-quality plants, you lower the risk of getting snails with the plants.

Either way is it a good habit to check every decor and plant for eggs and remove them. You could also dip your plants in a bleach solution, or hydrogen peroxide before rinsing them off thoroughly and plant them.

This way you destroy every egg that you might have missed.

You could use a snail-eating snail to remove other, unwanted snails, and then put in the snail you want.

The Clea Helena is eating other snails at a pace of about 1 snail per day. Make sure to put in enough Clea Helena to eat all the unwanted snails.

The Clea Helena is not reproducing very fast so they will not invade your fish tank. When the unwanted snails are gone, remove the Helena and put in the wanted snail (or not if you don’t want any).

There are also pufferfish eating snails.

If you want the pufferfish in your fish tank, this is a better route. But you cannot have any snails with it, and by that, you lose the benefits of having snails in your fish tank.

To lower the number of snails once you have the snails in your fish tank, make sure to keep the tank clean by doing regular water changes and feeding your fish less.

With less feeding, you will have the population of snails lower since the amount of food is more limited for them.

You should never remove snails by putting chemicals into the water.

The reason for that is that when a lot of snails die at the same time, which they will when doing it chemically, they also start to rot at the same time. This will release a lot of ammonia which will lead to an ammonia spike.

This ammonia spike will kill every other inhabitant in your fish tank.


I have been a fish keeper a big part of my life. During the years I have gathered and searched a lot of information about fish keeping and here, on the website, is where I share that information to help you with your fish keeping. I want to provide the information that I didn't get when I had a question about my fish tank.

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