Winter Pond Maintenance
Pacific Northwest winters are generally mild enough to keep your pond running all year with no additional maintenance steps, however, when the cold snap does arrive, it's good to know how to take care of your pond and your koi.
Maintenance is usually the determining factor in whether or not a pond owner keeps their pump running in the winter. The primary maintenance responsibility at this time is to make sure there is enough water for the pump(s) to operate properly.
Pump size is also an important consideration when determining a waterfall's ability to operate during the winter. A pump that provides at least 2,000 gph can be operated throughout the winter without a problem, as long as it runs continuously. The moving water will usually keep a hole open in the ice around the waterfalls and in front of the skimmer.
There is nothing more breathtaking than a waterfall covered with ice formations and snow during the winter. You must, however, be careful with ponds that have long or slow-moving streams. In such cases, ice dams can form and divert water over the liner.
And then there are your fish friends. What will become of them over the winter months? Do they hibernate like a bear and wake up in the spring when you're there to greet them for a clean-out? Can they survive in only two feet of water? Won't they freeze solid into little precious fish-cicles?
The fact is that ornamental fish will do just fine in two feet of water, as long as some form of oxygenation is provided, and a hole is kept in the ice to allow the escape of harmful gases. It's recommended to place a waterfall pump in a basket, bucket, or pump sock and surround the intake of the pump with stones to prevent clogging. Place the pump on the second or third shelf of the pond so the surface water is broken by the aeration. The agitation from the pump will prevent freezing and provide oxygen.
Another option is to use a floating heater/de-icer in combination with a small submersible pump (at least 150 gph). You can place the small re-circulating pump on the first shelf of the pond, bubbling at least one inch above the surface. Floating heaters are the most common method of keeping a hole open in the ice. Unfortunately they won't provide oxygen for the fish, and some can be expensive to operate.
Do not confuse a floating pond de-icer with a water heater. A pond de-icer won't heat the water; it will simply keep a small hole open in the ice. Be sure to place it away from re-circulating water to avoid moving the heated water. Just remember that although they seem like they're sleeping down there, they still need oxygen in order to keep going and to meet you when the ice melts!
If you feel that you can tackle the responsibilities of keeping your pond running during the winter, then go for it, because there's nothing quite like the breathtaking view of the winter pond in all its glory!