How to Keep Snails in Rimless Tanks: 4 Proven Methods

How to Keep Snails in Rimless Tanks

How to Keep Snails in Rimless Tanks: 4 Proven Methods

Rimless aquariums, with their sleek design and unobstructed views, have grown increasingly popular among aquarists. However, the open-top concept presents a unique challenge: How can we effectively keep snails in rimless tanks?

To keep snails in rimless tanks, consider using net tops or internal frames with acrylic tabs. Maintain optimal oxygen levels with proper aeration and choose substrates, such as sand or gravel, based on the snail species’ preference. Monitor water quality to discourage snails from trying to escape.

The rest of this article explores practical solutions to this conundrum, ensuring your snails remain comfortably within their aquatic realm.

Can Snails Crawl Out of Tanks?

For many, it might be baffling to think of a snail venturing beyond its aquatic confines. Yet, certain species, especially the adventurous nerites, often want to explore beyond the water line.

This behavior is not just about feeding but also expressing their natural instincts. The slimy trail they leave on the dry side of a tank bears testimony to their exploratory endeavors.

Why Snails May Leave the Water

Venturing beyond their watery domain isn’t just a whimsical journey for snails; specific reasons drive this behavior:

  • Oxygen Levels and Nitrates: While oxygen depletion or high nitrates might drive some species towards the surface, for rimless tanks with optimal aeration, this usually isn’t the primary factor.
  • Attraction to Algae: Algae, especially near the water’s surface, is an irresistible treat for snails. This green buffet lures them upwards, and once there, the outside world is just a small step away.
  • Natural Instinct: Nerites, being intertidal creatures, are hardwired to spend time both in and out of the water. This behavior is not merely a quest for food but also an instinctual drive, especially when it’s time to lay eggs.

Solutions Aquarists Recommend to Keep Snails in the Tank

Preventing these curious mollusks from making their great escape requires a mix of observation and ingenuity. Several strategies have emerged, thanks to seasoned aquarists:

Net Top

A top solution is the integration of a net top, seamlessly recessed into the tank’s top. This not only helps to prevent snails from escaping the aquarium but also deters fish from jumping. Its subtle design ensures it doesn’t detract from the tank’s aesthetics.

For those looking to implement a net top solution, the Shappy 6 x 7.2 ft Aquarium Screen Net is an excellent choice. This clear, durable nylon mesh net is customizable to fit various tank sizes. It features 0.31 x 0.31-inch mesh holes, ensuring adequate light penetration without compromising security. Not only does it keep snails and fish safely inside, but it’s also versatile enough for other applications.

Internal Frame With Acrylic Tabs

Here, a frame is set snugly inside the tank’s rim. This frame is firmly held in place using acrylic tabs, preventing accidental submersion. This is one of the most effective snail barriers for aquariums, especially rimless ones.

For aquarists searching for a secure solution to keep their internal frames in place, the Lasenersm Acrylic Aquarium Cover Clip is highly recommended. Crafted from high-quality, non-toxic acrylic plastic, these clear clips are designed for 7mm to 8mm thick glass. Not only do they offer a snug fit, ensuring your frame remains stable, but their easy installation and sleek design make them a go-to choice for rimless aquariums.

Regular Monitoring

A hands-on approach involves consistently observing your tank and placing any adventurous nerites back into the water, ensuring they stay safe.

Water Line Management

Creating a water level “safe zone” can deter nerites from venturing too far. By managing the water level, they can explore above the surface without crossing the tank’s boundary.

The Unique Behavior of Nerites and Other Snails

While nerites are often the main culprits when it comes to escape attempts, it’s essential to understand the behavior of other snail species to keep snails in rimless tanks effectively.

  • Nerites: As mentioned, these snails are naturally intertidal and will frequently attempt to wander beyond the water line. Their drive is primarily due to their inherent nature and sometimes due to the tank’s conditions.
  • Mystery Snails: Another snail often in question is the mystery snail. If you notice your mystery snail frequently attempting to leave the tank, it might indicate water quality issues or a search for a laying ground for their eggs.
  • Other Species: Most other snails, like Ceriths, trochuses, stomatellas, and collonistas, prefer staying within their aquatic environment, primarily feeding on algae and detritus. Their tendency to stay submerged makes them less of a concern about rimless designs.

Substrate Considerations: Sand or Gravel for Snails?

The substrate type is one critical consideration when setting up an environment to prevent snails from escaping the aquarium. The choice between sand or gravel isn’t just aesthetic but also impacts the snails’ well-being.

Recommended Reading: Can Snails Be in a Tank With Sand?


Sand offers a smooth surface for snails, allowing them to glide effortlessly. It’s particularly favored by burrowing snails, offering them an ideal environment to dig and lay eggs. Additionally, sand reduces the chances of food particles getting trapped, which can help maintain better water quality.

For aquarists seeking pristine quality, the AquaNatural Sugar White Sand is an excellent choice. Triple-washed, kiln-dried, and 100% natural, this off-white sand brightens up your tank and stays put with its dense composition of 0.5 – 1mm grains. Ethically sourced from New Zealand, it’s perfect for aquariums and terrarium setups, ensuring a beautiful contrast with plants and décor.


While gravel can be aesthetically pleasing and aid in some filtration methods, it might pose challenges for snails. The gaps between the gravel pieces can trap food, leading to water quality issues. However, certain snail species don’t mind navigating the rugged terrain that gravel provides.

For those leaning towards a gravel substrate, the AquaNatural Gold Pearl Gravel Substrate stands out. It’s 100% natural and safe for aquariums. Its triple-washed, 2-4mm particles sourced uniquely from New Zealand ensure aesthetic charm and a safe environment for your aquatic friends. The golden hues will add a touch of luxury while providing a natural habitat for snails and other aquatic species.

When selecting the substrate, it’s essential to consider both the snails’ preference and the tank’s overall health. While sand might be a more natural environment for many snails, gravel can be managed with regular cleaning and monitoring.

Addressing Water Quality to Prevent Escapes

Ensuring high water quality is paramount to prevent snails from escaping the aquarium. As some aquarists noted, snails might attempt escapes when facing oxygen depletion or high nitrates. Thus, regular water testing is crucial.


Adequate aeration ensures that oxygen levels remain optimal. This not only benefits snails but also other aquatic life. Air stones or bubblers can be introduced to promote better oxygen circulation.

For those keen on enhancing aeration in their tanks, the Pawfly Aquarium 1-inch Air Stone Cylinder is a top pick. Despite its compact size, it’s designed for consistent, efficient bubbling. It boosts oxygen solubility with its dense medium bubbles, perfect even for small aquariums. This air stone promises durability and ensures the well-being of your aquatic life.

Regular Water Changes

Regular water changes help keep nitrate levels in check. This not only ensures the well-being of the snails but also deters them from trying to escape.

Monitoring for Algae

While snails feed on algae, excessive algae growth can indicate nutrient imbalances. By managing nutrients and lighting, one can control unwanted algae blooms.

Recommended Reading: Best Algae Killers for Your Snail Tank: Top 4 Reviewed

Incorporating Snail Barriers for Aquariums

The idea of snail barriers might sound complex, but they can be both efficient and unobtrusive. Egg crates, as mentioned by some aquarists, are an innovative approach. Placed subtly beneath the water line, they act as a gentle deterrent, guiding snails away from the edges.

For those with a penchant for technology, while the idea of an “electronic barrier” is cheeky, there are indeed advanced solutions in the market that deter snails using safe, low-voltage currents. Always ensure any solution is humane and doesn’t cause harm or stress to the snails.


Rimless tanks offer a sleek, modern appeal, merging the boundaries between aquatic and terrestrial worlds. However, the challenge of keeping snails in rimless tanks can be an adventure of its own.

Through understanding, observation, and ingenuity, aquarists can ensure their snails remain safely within the tank’s confines. Embracing the delicate balance of beauty and function, one can enjoy the tranquility of a rimless tank, snails, and all.



  • Paul Odoteh

    Paul Odoteh is an established writer and editor with nearly 10 years of experience in writing and editing. He holds a bachelor's degree in IT and has written for numerous publications and individuals. Currently, Odoteh is dedicated to expanding his blog,, which was inspired by his passion for owning an aquarium.

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