Written by Tammy Law (@aquarist_tl) and Team Buce Plant

There may have been a time when you bought or received live plants for your aquarium, and then immediately placed them into the tank once you arrived home. Several days or weeks later while you’re observing the tank, you spot a random snail or two. A few weeks or months pass by, and suddenly there are snails in every spot of the aquarium you look at! This overpopulation is a common occurrence for those who first encounter pest snails in the hobby, and leaves many aquascapers mulling over the following questions:

Where did these snails come from? 

Are these snails harmful to the aquarium? 

What kind of snails are they? 

How do I get rid of them?

This article will answer all those questions and more! 

Where did they come from? 

Sneaky Stowaways

Pest snails and planted aquariums often come hand in hand with one another. This is largely due to how the snails or snail eggs hitch rides into tanks through live plants. 

Snails are a natural part of your aquatic plant’s environment! Aquatic plant farms usually mass-produce plants in huge ponds or containers. These ponds could be teeming with snails. Plants that are consciously collected can contain these critters as well. 

When a plant order is sent out, keep in mind that some of the plants may contain eggs or snails attached to them. Most snails breathe air and just need water to prevent them from drying out. This goes for their eggs as well. Most pest snails reproduce by laying clutches of eggs. The eggs are held in clear, jelly-like sacs that stick to surfaces like plants and other objects. Since the eggs are so tiny and are in clear sacs, it’s difficult to see them and they can easily be transferred to other aquariums undetected.

A clutch of snail eggs on a piece of driftwood

When shipping live plants, the plants will normally be kept sealed in a plastic bag to maintain moisture throughout their trip. This gives the potential snails and their egg clutches the ability to survive the trip as well. Once the plants arrive at their new home, they’re usually immediately placed in a tank where snails are free to explore their new homes and the eggs are ready to hatch. 

This is why many aquarists will quarantine or perform a bleach dip for their new plants before placing them in their tank. Click here to learn more about bleach dip your aquatic plants.

Although live plants are a common way for snails to make their way into your aquarium, it is not the only way. Anything added to your tank from another aquarium could have snails or snail eggs on them if the aquarium the object came from had snails. Whether it’s substrate, a filter, or decoration, snails or their eggs can catch a ride on basically anything. 

If you’re moving something from a snail-infested tank to one with no snails, it is likely your new tank will start its own snail population. In my own experience, I was moving substrate from one planted tank to a new one. I dried the substrate out for a few days thinking that was enough to prevent snails in the new aquarium. A few days after the set up, I found snails out and about roaming the new tank! 

Rapid Reproducers

Once you spot one snail in the tank, in many cases it won’t be long before it seems like there is an abundance popping out from every corner. One of the reasons why these mollusks are commonly called “pests” in the aquarium hobby is because of their rapid rate of reproduction. 

There are three main factors that contribute to their ability to reproduce and overpopulate so quickly:

1. Fast Reproduction

• Many types of snails lay eggs with each egg sac containing dozens of eggs.

2. Quick to Mature

• Snails grow quickly, which means they start reproducing quickly!
• Some species can begin reproducing at only 35 days of age.

3. Many Species Are Hermaphrodites 

• This means they have both male and female reproductive organs. When reproducing, snails will adapt to their partners through chemical cues. One will take on being the female, while the other will be the male. So even if there are just two snails in the aquarium, they will typically be able to reproduce, regardless of their sex. 
• Many are able to reproduce asexually without another snail present. This means a single snail would be able to reproduce solely on its own by basically cloning itself!

Are these snails harmful to the aquarium? 

Harmless Helpers

Although they are often called pests, these aquatic snails actually transform your aquarium into more of its own ecosystem. Most snails are beneficial to aquariums because they are detritivores. In other words, they eat decaying matter such as fish waste, uneaten food, and rotting plants.

Like earthworms in soil, aquarium snails further break down the detritus of the tank, enabling easier utilization for plants and bacteria. They also like to feed on algae in the aquarium, which is a great benefit for most aquarists because algae in or on the tank can be considered unsightly. 

Since most of these species are so small, they can crawl into cracks and crevices in the tank that fish would be unable to get into. These snails would be able to reach the areas of the tank where small foods can slip into and eat them before they go bad in the aquarium. The Malaysian trumpet snail in particular will even dig through the substrate to look for food that may have been burrowed in. This adds extra breakdown for the aquarium. Their digging also churns the substrate up a bit, preventing it from becoming anaerobic.

Malaysian Trumpet Snails

Many people believe pest snails eat the plants in their aquariums and chew holes through them. However, it has been found that these snails rarely go after healthy plants, and if they are snacking on leaves, then those leaves are most likely dying. 

For example, a pest snail or two may be chewing on a leaf of your newly added emersed-grown plant. This is because when an aquatic plant is grown out of water and then submerged, it takes a while for the plant to transition into its submerged state. All or most of the emerged grown leaves will die and start decaying in the water, which is a common reason you may find these snails “attacking” your plant. So really, these pests are helping the aquarium by eating what would soon become debris!

What species of snails do I have in my aquarium? 

Listed below are 3 most common species of aquatic snails that may be considered pests in freshwater aquariums with some general noted facts about each respectively:

1. Bladder Snails (Physella acuta)

• Appearance: Teardrop-shaped gray shells with yellow spots
  - Can grow to be about ½ in.
  - Calcium is necessary for growth of a bladder snail’s shell
  
  
• Diet: Omnivore - will eat decaying plants, algae, leftover meat or fish food, insects
  
  
• Reproduction: Hermaphrodite - they are of both male and female sex
  - Asexual reproduction is possible
  - Reproduces quickly
  - Are ready to breed when they reach around 40 days old
  - Lays many clutches of eggs on all surfaces in a tank with each clutch potentially holding dozens of eggs
  
  
• Life Span: Up to 2 years
  
  
• Other details: Air- breathing and can be seen walking upside-down along surface of water to breathe
  - Very hardy! These snails can adapt to a large range of water conditions
  - 64F-84F but prefer cooler water
  - Can survive a large range of pH levels
  
  
  
  

2. Malaysian Trumpet Snails (Melanoides tuberculate)

• Appearance: Cone-shaped cream or brown colored shell which allows it to dig into substrate
  - This process prevents the risk of harmful gas pockets building up in your substrate that can be harmful to your fish or shrimp
  - Provides extra breakdown of any detritus that has slipped under substrate
  - Can grow up to 1 in.
  
  
• Diet: Omnivore - will eat decaying plants, algae, leftover meat or fish food, insects
  
  
• Reproduction: Live-bearing snail - not hermaphroditic
  - Females can reproduce with or without males
  
  
• Life Span: Up to 3.5 years
  
  
• Other details: Nocturnal clean-up crew that comes out when the lights go off (They usually burrow under the substrate during the day)
  - Very hardy! These snails can adapt to a large range of water conditions
  - Prefer temperatures of 65F-85F
  - Can survive a large range of pH levels
  - Has gills and can breathe underwater

3. Ramshorn Snail (Planorbidae)

• Appearance: Their shells are round with a spiral like a ram’s horn
  - Comes in different colors (e.g. red, pink, blue, etc.)
  - Harder water (calcium) helps strengthen their shells 
  - Can grow up to 1 in.
  
  
• Diet: Omnivore - likes to eat decaying plants, algae, leftover meat or fish food, insects
  
  
• Reproduction: Hermaphrodite - they are of both male and female sex
  - Asexual reproduction is possible
  - Reproduces quickly
  - Lays clutches of eggs with each clutch potentially holding dozens of eggs
  
  
• Life Span: Up to 1 year
  
  
• Other Details: Air-breathing snail. Very active and will move around your entire tank day and night. 
  - Hardy - can adapt to a range of water conditions
  - Prefers temperatures of 65F-80F
  - Prefers pH of 7-8
  - Miniature ramshorn snails (Planorbis arnoldi) won't grow larger than 5 mm.

How do you get rid of pest aquarium snails? 

Mollusk Management

Even though snails are capable of providing many benefits to an aquarium, some hobbyists may think they are unsightly in their tanks or they just simply don’t like them. 

There are several methods you can use to reduce the population of pest snails in your aquarium. 

1. One of the most impactful ways is to lower their available food sources.
Try to avoid overfeeding your aquarium, as the snails are likely to go after uneaten food; especially foods like pellets and wafers that sink to the bottom of the tank. You can also lessen the snails’ food sources during aquarium maintenance. Scraping the algae off the sides of the aquarium prevents them from snacking on it. Vacuuming your substrate helps remove any detritus that they may chow down on. Lastly, removing dying plants or leaves will also aid in this conquest. 

2. Another tactic to get rid of some of these aquatic mollusks is through manual removal.
You can try to remove the snails from the tank each time you see them. There are snail traps you can buy or create that lure the snails into them, allowing for easy removal of many at a single time. You can put out romaine lettuce traps to attract the snails as well, then simply lift the lettuce right out of the tank once they have gathered to start munching.

Pea puffers eating bloodworms.

3. Depending on the size of the tank and its inhabitants, you can try adding a critter into the aquarium that will feed on the snails.
Loaches and pufferfish are well-known for eating snails! For smaller tanks, pea puffers love going after snails. The snails help the puffers as well, dulling their ever-growing teeth when they bite on the snails’ hard shells. For larger tanks, loaches would be a good fit. Their long and skinny snouts allow them to dig through the shells of the snails. There’s also the assassin snail, a carnivorous snail that will feed on other snails. Before approaching this method, make sure to do research on whichever fish you’re thinking of adding into your aquarium! Some of these snail-eating species can be aggressive. 

Yoyo loach on the lookout for some food.


4. Keeping up with regular water changes is highly recommended!
Remember, snails thrive on algae and decaying plant matter. The cleaner your tank, the less snails you will have. Frequent water changes will remove detritus buildup. During your water changes, make sure to scrape any algae from the glass and vacuum any excess debris and waste. Check out the Qanvee Gravel Vacuum Siphon for easy vacuuming during water changes. Try and make it your goal to perform a water change at least once a week. This will always help the overall condition of your entire tank. Click here to learn more about the importance of water changes.

5. Finally, the best way to get snails out of the aquarium is to prevent them from even getting there in the first place. When buying live plants, ensure they are pest-free by quarantining them or performing a bleach dip. Click here for a safe and easy guide on how to bleach dip plants. When quarantining, make sure to go a minimum of 2 weeks to see if the plant has any eggs or snails. You can then manually remove any snails you see. Another way to get plants that are guaranteed to have no snails is to purchase tissue culture aquatic plants instead. Tissue culture plants are as clean as you can get and are guaranteed to have no snails, algae, or pesticides. 

So, if you happen to find snails in your aquarium, don’t worry! It’s not the end of the world (or your tank.) They are peaceful creatures that do more good than bad. As long as you keep up on maintenance and try not to overfeed, their population shouldn’t get out of control. If you want to avoid having snails in your tank, make sure to follow the prevention tips previously mentioned. Happy scaping!

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