How To Winterize Your Pond

How to winterize your pond. As the days grow shorter and the temperature falls, there are a few things you should do to get your pond ready for the winter and help ensure a healthy pond next spring.

You might also look at How To build a Winter Pond Cover

Fish Care in Winter

Goldfish and koi are very hardy fishes; they can survive water temperatures as low as 0°C, which means they can survive in the pond over the winter as long as it doesn’t freeze solid. To help ensure healthy fish in the spring, follow these steps:

1. Feed a Fall Food such as Hikari, Legacy, Tetra or Profishent once the water temperature falls below 18 °C and gradually reduce the amount that you feed as the temperature drops. Stop feeding once the water temperature consistently remains below 10 °C.
2. Keep tree and plant leaves out of the pond. Leaves and other organic matter will continue to break down through the winter months causing poor water quality and low oxygen levels in the pond. The easiest way to do this is to use a net to cover the pond and waterfall.
3. Remove sludge and debris from the bottom of the pond. Use a fine mesh net or a pond vacuum to keep the bottom clean. We have daily pond vacuum rentals for customers who want to periodically give their pond a thorough cleaning.
4. Add Microbe Lift Autumn Prep. It contains beneficial bacteria and enzymes to break down any residual sludge and organic matter and sustains biological activity in the cold water through the winter to help maintain good water quality and keep your fish healthy until spring.
5. Maintain a hole in the ice to allow oxygen into the pond and noxious gasses out of the pond. A heater is generally the best choice for keeping the pond open. The most reliable heaters are either Thermo-Pond (100 W), PondMaster (120 W) or Tetra (300 W). Aerators can also be used to keep a hole open in the ice. The water current produced by the rising bubbles prevents water from freezing and also provides circulation. We also carry larger aerators by PondMaster for larger pond. For best results heater and aerators are best used together.
6. Adding Pond Salt is also beneficial to fish. A concentration between 0.1 and 0.3% is ideal (approximately 1 lb to 3 lb of salt per 100 gallons of pond water). The salt concentration can be easily measured using a PondCare Salt Level Test Kit. See our ‘Salt in the Pond’ page for more information .

Plant Care in Winter

Hardy Water Lilies are easily wintered, just cut back the yellowing leaves and submerge the lilies to a depth where they will not freeze, usually 2 feet is sufficient.

Lotus can be wintered in the same manner as water lilies. Lotus will survive the winter as long as the tubers do not freeze solid.

 Marginal Plants

Hardy plants can survive even if they freeze solid, as long as they stay in the pond. These plants include irises, sweet flag, rushes, reeds and horsetails. They can be submerged to deeper depths, but they will also do well if left near the surface.

Marginally Hardy plants can survive the winter cold, but will die if their crown becomes frozen. These plants include: pickerel plant, hardy water canna, parrot feather, water clover, water parsley and cardinal flower. To winter these plants submerge them below the ice line.

Tropical Plants will not survive the winter outdoors. But many of these plants will grow easily in the house if brought inside before the first frost, placed in a container of water and given plenty of light. Plants such as Umbrella palm, papyrus, cannas, taro, bog lily, etc. can be brought inside and make great house plants

Winter Pump Care

In most cases it is best to remove your pumps from the pond, clean it thoroughly and store it for winter. If you have a direct drive style pump (not a magnetic drive or asynchronous pump) then it should be stored in water and protected from freezing. This helps to keep the seals moist. If you have a magnetic drive or asynchronous pump they can be stored anywhere dry.

Filters & Ultraviolet Lights

Waterfall style filters can be left in place but should be drained. It is best to remove the filter pads and bio-media, clean them thoroughly and store somewhere dry.

Pressurized filters should be drained and stored inside somewhere dry. It is best to remove the filter pads and bio-media, clean them thoroughly let them dry and store them back inside the filter.

UV lights should be disconnected, cleaned and stored somewhere safe where there is no chance of them falling and breaking the quartz sleeve and bulb.

Waterfall Care

We often get asked by customers if they should leave their waterfall running all winter. Here in central Ontario, I recommend that you shut down your waterfall and remove the pump from the pond. Temperatures here can get quite cold and ice ‘dams’ can form diverting water out of the pond, draining your pond before you know it. Another reason to shut down your waterfall is that you can chill your pond even more than normal by exposing the pond water passing over the waterfall weir to the very cold air. We will often leave our waterfalls running into early December so that we can get some nice ice formations like in the photos above.

Insulating the pond, is another way to prevent a thick ice formation. If your pond is not too large, you can insulate it by laying boards across the pond, cover them with plastic, and insulate it with styrofoam, a thick layer of leaves or anything else that would provide insulation.