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Do I need to provide indoor shelter for my pond snails? | Decorative Ponds & Water Gardens Q & A

Q: Do I need to provide indoor shelter for my pond snails?

Q: Do I need to provide indoor shelter for my pond snails?

Jerry – Kernersville, NC

A: Scientists have identified an estimated 4,000 species of freshwater snails, but one that you might find inhabiting your backyard pond or water garden is the Japanese Trapdoor Pond Snail, also known by its scientific name Viviparis malleatus.

These algae-eating gastropods have extra-special shells with a hinged fingernail-like plate that allows them to seal the shell’s opening, providing protection from drought and predation—hence their “Trapdoor Snail” nickname.

Though these hearty snails overwinter well in harsher northern climates, they do require some attention when temperatures dip. Here’s what you need to know:

  • Cool with Cold-Temperatures: These snails really do well in colder temperatures—in fact, some experts say they’ll do fine in sub-freezing weather, even down to 0 degrees Fahrenheit. When it gets really frigid, they’ll dive to the bottom of the pond, where the water is warmer.
  • Adequate Pond Depth Required: In order for them to be happy and healthy through those chilly winter spells, the snails need the water in your pond’s depth to ideally be 20 to 30 inches. Down there, they’ll happily groom the bottom of your pond, gobbling all the decaying matter like leaves, excess fish food and fish waste.
  • No Habitat Required: Because these little guys carry their homes on their back, you don’t need to provide shelter or food for them. If they feel endangered, they’ll disappear into their shells; if they’re hungry, they’ll nibble on algae that’s on your plants, underwater pots, rocks and walls.
  • Aeration Appreciated: Like any aquatic critter, Trapdoor Snails appreciate oxygen-rich water, and that’s where a subsurface aeration system, like the Airmax® PondAir™ & Thermo-Pond De-Icer Combo, will help. An unit like this will infuse your pond with oxygen while releasing harmful gases.

If you have other types of snails in your pond or water garden, these rules may not apply—so be sure to learn their care requirements as they may need more attention than these hearty Trapdoor Snails.

Pond Talk: Do you have other types of snails in your pond? If so, what kind of care do they require?

Vent Harmful Gases All Winter - Airmax® PondAir™ & Thermo-Pond De-Icer Combo

 

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Will the snails I added last year still be in my pond? | Decorative Ponds & Water Gardens Q & A

Q: Will the snails I added last year still be in my pond?

Q: Will the snails I added last year still be in my pond?

Phoebe – Amherst, NH

A: Snails are a pond keeper’s best friend – especially when it comes to gobbling through algae.

The type that you probably have in your backyard water garden is the Japanese Trapdoor Snail. They get their name from their fancy shells, which have a hinged fingernail-like plate that allows them to seal the shell’s opening, providing protection from drought and predators.

Cold-Weather Friendly
These little guys are hardy enough to weather cold temperatures, like the ones we had all winter. Unlike other aquatic snails, Japanese Trapdoor Snails lack a lung, which means they don’t need to surface to suck in frigid (and potentially deadly) oxygen in the winter. They’re ideal for harsher northern climates.

Hiding Places
When the spring and summer sunshine warms the water, you might not see your snails. They like to hang out on the bottom of ponds, and they blend in incredibly well with rocks, gravel and plants. But they’re hard at work doing what they do best – eating algae and the detritus that feeds it. They also do a great job grooming plants and keeping your rocks and plant pots algae-free.

Strength in Numbers
For maximum algae-eating benefit, we recommend housing a minimum of 10 snails per 50 square feet of pond. If you have a farm pond or larger water feature, you’ll need at least 200 snails to have any effect at all. Remember that they will reproduce a few times a year, and tiny newborn snails are hungry!

Aerated Water, Happy Snails: Keep those helpful gastropods happy all year-long by providing plenty of oxygen-rich water. The best way to do that is by aerating your pond with a subsurface aeration system, like the PondAir™ Aeration Kit. Featuring two air stones and flexible black vinyl air tubing, an adjustable unit like this will infuse your pond with oxygen while remaining whisper quiet.

Pond Talk: Have you had success controlling algae in your water feature with snails?

Breathe Life Into Your Pond - Airmax® PondAir™ Aeration Kits

Do Snails Need To Be Acclimated When Being Added To My Pond? | Decorative Ponds & Water Gardens Q & A

Do Snails Need To Be Acclimated When Being Added To My Pond? Do Snails Need To Be Acclimated When Being Added To My Pond?

Bonnie – Fallston, MD

Like fish, snails also need to be acclimated to a pond. It may seem strange since the anatomy of a fish and snail are so different, but snails like the Japanese Trapdoor are also susceptible to shock from early-season chilly waters if they are not acclimated. However, these snails are best for pond life because they are live bearing and don’t reproduce as quickly.

Acclimating snails is the same process as acclimating fish to new pond water. Upon arrival, leave the snails in the bag and float it in the pond for 10 to 15 minutes. Once you have floated the bag you will want to remove the snails from the most newspaper and place them in the pond. By then they should be acclimated to the temperature and be fine.

Black Japanese Trapdoor Snails

Will snails survive the winter in my pond? | Decorative Ponds & Water Gardens Q & A

When should I remove the fountain from my pond?

Will snails survive the winter in my pond?
Cody – Falling Spring, VA

While your fish and some of your aquatic plants remain safe and sound during their winter dormancy you may wonder if your snails will be as successful. Your pond snails are amazingly resilient in cold weather and will do just fine given their habitat is suitable.

Your pond depth will play a major role in the success of all of the living creatures in your pond. Your plants, fish and snails can survive in cold water but they won’t fair too well if frozen into a solid block of ice. The ice that forms on the top of your pond varies in thickness depending on where you live but the general rule of thumb is to build your pond to be around 20”-30” in depth. This ensures there is an ample layer of water at the bottom of the pond that is left unexposed to the elements which will provide a safe haven for all of your pets and plants.

You won’t have to worry too much about your snails finding a safe place to hide over the winter as they come equipped with a strong shell which provides adequate shelter. They can hide amongst the rocks and plant remains in the pond as well during the winter but as your fish are in dormancy there is not an overwhelming need for additional habitat. As water temperatures drop and bacteria begin to dwindle a lot of pond owners tend to rely on algaecides to keep their ponds free from algae. If you are using an algaecide in your water garden review the product label thoroughly to ensure it is safe to use with your snails. When your pond comes back to life in the spring your snails will flourish amongst the new plant growth.

Pond Talk: Do you do anything special to provide safety for your snails in the winter?