Snails Gone Wild: How to Keep Them From Taking Over Your Tank

Experienced hobbyists will tell you that snails are an important part of your aquarium’s ecosystem. And they’re right.

They keep your tank walls clean by munching on algae; they also feast on leftover fish food and plant debris. 

Generally, they act as your tank’s clean-up crew.   

 

But snails have a wild side, too.

Some species can quickly multiply and overrun an aquarium if left unchecked.

When this happens, they become 'pest' snails.

Note, that we aren't talking about algae eaters like Nerites. These guys need a brackish water setup in order to complete their lifecycle, so they won't ever breed for you in your standard freshwater setup.

The "Wild" Side of Snails

For the purposes of this post, we will be talking about snails that can hitchike on plants from tank to tank, and rapidly multiply, seemingly without help from you and I.

These 'Pest' snails are Ramshorns, Bladder, Pond, and Malaysian Trumpet Snails.

 Here’s what can cause this issue:

• Overfeeding: When your fish is given more food than they can eat, excess food sinks to the bottom and becomes snail food.
• Uneaten Food: Leftover food decomposes, creating detritus that snails thrive on.
• Specific Snail Types: Some species, like bladder snails, Ramshorns and Malaysian Trumpet snails, reproduce rapidly.

A large snail population can have a few minor downsides:

• Competition for Food: Too many snails compete with your fish for resources.
• Aesthetic Issues: An excess of snails can make your tank look messy and crowded.
• Posibility of contamination: If you pass plant cuttings or decoration along to fellow hobbyists, snails and eggs are likely, and may be unwelcome.

Your once-pristine tank might start looking like a snail farm instead of a carefully curated underwater ecosystem.

Keeping Your Tank Balanced: Prevention Strategies

Keeping snails under control in your aquarium starts with proactive measures and regular maintenance.

Here’s how you can prevent a snail invasion:

Start with a Clean Slate

Begin with a clean tank to avoid unwanted snails. Inspect and thoroughly clean all new plants, bulbs, botanicals. and decorations like rocks and driftwood before adding them to your aquarium. This step helps ensure you don’t introduce hitchhiker snails.

Consider starting with Tissue Cultures

These are lab- grown and sterile plants that may be a bit more expensive than regular farm- grown plants.

Many hobbyists who are adamantly against pest snails find the extra cost to be worth the pain.

Quarantine New Additions

Quarantine any new additions, for example, new plants, to your tank.

Let any hidden snails take the time to hatch out, and go exploring so you can pick them off.

Most pest snails lay a translucent jelly clutch with eggs inside. You can scrape off this sac easily with a fingernail.

This extra step helps you catch any snails or snail eggs before they enter your main aquarium.

For reference: this is what a clutch of baby ramshorn snails looks like right before it hatches:

Maintain a Healthy Ecosystem

A balanced tank keeps snails in check naturally.

Here are some common-sense policies to keep your tank as inhospitable to snails as possible. Note that some of these ideas won't work for your particular set-up, and that's ok!

Control Feeding

• Feed fish only what they'll eat in 2-3 minutes, once or twice daily.
• Remove uneaten food after 5 minutes.
• Try feeding smaller amounts more frequently instead of large meals.
• Use a feeding ring to contain food and make cleanup easier.

Regular Tank Maintenance

• Do 20-30% water changes weekly.
• Vacuum the substrate during water changes.
• Rinse filter media monthly in old tank water.
• Wipe or scrape down tank walls to remove algae.
• Trim dead or decaying plant matter promptly.

Substrate Selection

• Consider fine sand or small, smooth gravel.
• Avoid large, chunky substrates with lots of gaps.
• If using planted substrates, cap with a fine layer of sand.
• Stir or rake the substrate gently during cleaning to prevent debris buildup.

Plant Management

Fast-growing plants are your allies in the battle against snails (and algae!). They absorb excess nutrients, keeping your tank balanced.

Here are some super basic, super easy species to consider:

• Hornwort (Ceratophyllum demersum
• Water Wisteria (Hygrophila difformis
• Amazon Sword (Echinodorus bleheri):
• Duckweed (Lemna minor):
• Java Moss (Taxiphyllum Barbieri
• Anacharis (Elodea densa)
• Water Sprite (Ceratopteris thalictroides)

Do the following when adding these plants:

• Start with a few from a trusted source, and clean them well before introducing them to your tank.
• Trim regularly to prevent overgrowth and maintain healthy plants.
• Provide appropriate lighting and fertilization for optimal growth.
• Remove any dying leaves promptly to maintain water quality.

Additional Control Methods

If you’re dealing with a snail infestation, these options serve as secondary measures:

Predatory Animals

Introduce peaceful predator fish like pea puffers or dwarf puffers, which are known for eating snails. For nano tanks, consider Sparkling Gouramis , or Assasin Snails. These tiny hunters can help keep snail numbers down.

Just make sure they play nice with your other tank residents.

For example, Assassin snails will go after your Nerites and Mystery snails as well.

Gouramis and Pea puffers may harm Dwarf shrimp.

Do your homework on compatibility before adding new fish. Always research compatibility to ensure they fit well with your tank's current inhabitants.

Chemical Control (Last Resort)

As a last resort, use commercially- available snail removal products.

However, you should use these products carefully. Follow the instructions to the letter.

You want to avoid harming your fish while tackling the snail problem. Remember, a healthy ecosystem is always the best long-term solution.

Takeaway

While snails play a valuable role in aquarium ecosystems, they can quickly become problematic if their population explodes. 

Maintaining a balanced tank through proper feeding, regular maintenance, and smart plant choices is key to keeping snails as helpful cleaners rather than unwanted pests.