Q: Do I need a heater to overwinter my fish in the pond?
Pat – Far Hills, NJ
A: Unless you house warm-water fish like Plecostomus in your water feature, you won’t need a heater to heat things up. Most pond fishes, including koi and goldfish, will overwinter just fine in their outdoor digs because they go into a pseudo-hibernation state when water temperatures fall. Their metabolisms slow and they’re able to tolerate cooler water—even water that’s frigid enough to freeze.
If you live in a climate that experience those freezing temperatures, what we recommend is a de-icer or aerator (rather than a heater) to keep a hole in the ice. This hole allows for gas exchange, through which necessary gases like oxygen enter and harmful gases like ammonia escape.
Which option is right for you?
- De-Icer: A de-icer’s purpose is to float on the surface and melt a hole in ice that has formed on a container of water, whether a koi pond or water garden. Unlike a heater that actually warms the entire body of water, a de-icer like the K&H™ Thermo-Pond 3.0 Pond De-Icer simply melts an opening in the ice sheet, thereby allowing for gas exchange.
- Aerator: Rather than create a hole in the ice from above, an aerator, like the PondAir™ Aeration Kit, circulates the water below the ice sheet. In areas with relatively mild winters, that subsurface water movement will keep a hole in the ice that allows for gas exchange—but when temps really dip, an aerator may not be enough to maintain a vent hole.
- De-Icer, Aerator Combo: An excellent and convenient option to consider is the PondAir™ & Thermo-Pond Combo. It combines both the Thermo-Pond and PondAir™ Aeration Kit, providing your water feature the one-two punch it needs to stay well-vented throughout the winter.
If temperatures in your area vary between above- and below-freezing, consider installing a ThermoCube®. The thermostatically controlled outlet turns on when air temperatures drop below 35° Fahrenheit and turns off when air temps rise above 45°F. This handy-dandy device will save you money, which is something we can all appreciate!
Pond Talk: What do you do to keep your finned pals comfortable in the winter?
Filed under: Aeration - WG, Deicer, Seasonal Care, Water Gardens & Features, WG-Winterizing Tagged: | de-icer, de-icers, Deicer, how do i get my pond ready for winter, pond winterization, Thermo Pond, thermocube, water garden aeration, winter aerator