To learn about the various tools we use to maintain your pond's vitality throughout the cold months, click here.
Do I need to turn off my waterfall in the winter?
If you have a waterfall on your pond, you may choose to keep it running during the winter and enjoy the stunning ice formations that develop, but you'll need watch it to make sure the ice doesn't divert the flow of water outside of the pond. (If that were to happen, you'd want to immediately turn off the waterfall pump to prevent further water loss, and switch to an in-pond aeration system to keep the water oxygenated for your fish.) If your winters get too cold for the water in the waterfalls to stay liquid, you'll want to turn it off and bring the pump in for the season, then add an aerator and/or heater to maintain a hole in the ice.
How to choose between a heater and an aerator
Both a heater (de-icer) and an aerator perform the essential (to your fish) function of keeping open a hole in the ice atop your pond. Knowing which is most appropriate for you depends on the specifics of your pond. The main variable is whether or not you have fish. Fish require both aeration and off-gassing of the water, whereas ponds without fish do not, and can be over-wintered without the need for a heater/aerator. Next, you must know approximately how low the temperature drops during winter in your area. If it never gets below 20-degrees Fahrenheit, you may be okay with just using the waterfall for aeration and keeping the surface open. If you're on the threshold of that limit, or if you have a heavy fish load requiring ample oxygenation, it would be a good idea to use additional aerators in your pond for the cold season. The air-stones should be placed on the shallowest shelf of your pond to minimize the introduction of freezing-cold air to the depths where your fish will be spending their winter. If it drops below 20-degrees, you'll need to supplement with a heater to keep the ice from overtaking your pond. At that temperature, just keeping the water moving with an aerator may not be sufficient to prevent it from freezing.
In cases where there are very low temperatures and a large fish presence, it makes sense to use both a heater and an aerator together. For the maximum efficiency, place the air stone beneath the heater; they will work in tandem and allow more gas to escape the water.
It's a good idea to keep a record as you monitor the water temperature during the fall months. This will help you recognize when to do your seasonal maintenance. As your water temperature drops below 65 degrees Fahrenheit, it will be time to make a change to your fish's diet to a cold-water food. The right cold-water food will have less protein, more fiber, and probiotics to help the fish adjust to a slower metabolism. As the water drops below 50 degrees, it will be time to stop feeding the fish altogether until the springtime.