A: Yes, those pond heaters are expensive to run! But guess what? You don't need one in the first place! Heaters are more frequently used in aquariums, particularly those that house warm-water fish like tetras or angelfish.
In your pond, the fish will overwinter just fine without a heater—even if temperatures drop below freezing. Pond fishes like koi and goldfish naturally go into wintertime hibernation when temperatures fall. They'll stop eating, their metabolisms will slow way down and they'll snooze through the winter without worrying about how warm their water is.
However, if you live in areas that experience freezing temperatures that cause your pond to ice over, you do need to worry about keeping a hole in the ice. The hole allows toxic gases like ammonia to escape while allowing oxygen in, and your fish will need that fresh O2.
So how do you create that hole? Not with a pond heater! Check out these much cheaper alternatives:
- De-Icer: A de-icer floats on the water surface and melts a hole in the ice. Unlike a heater that actually warms the entire pond, a 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 (for smaller ponds) or Pond Aerator (for larger ponds) circulates the water below the ice sheet. In areas with mild winters, that subsurface water movement will keep a hole in the ice—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 de-icer and PondAir Aeration Kit, providing your water feature the one-two punch it needs to stay well-vented throughout the winter. Watch the video for benefits and installation.
If you live in an area with temperatures that hover around the freezing mark, consider picking up a
Thermo Cube. It's a thermostatically controlled outlet that turns on when air temperatures drop below 35°F and turns off when air temps rise above 45°F.
So put that pond heater on Craigslist and invest in a de-icer, aerator and thermostatically controlled outlet. It'll save you money in the long run!