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.
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.
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?