Frequently Asked Pond Winterizing Questions

Q. How do I get my pond ready for winter?

Here is summary of activities for the fall for winter preparation:
  1. Reduce the number of leaves falling into the pond or remove them with a net.
  2. Do a “Fall Big Clean” (See “When should I do a big clean out?”)
  3. Cut back dead or dying aquatic plant foliage during the fall.
  4. Purchase a wheat germ-based pond food such as TetraPond Spring & Fall Diet
  5. Disconnect the pump, filter and UV clarifier before water freezes.
  6. Store UV clarifier indoors for protection.
  7. Store filters indoors (if manufacturer’s directions suggest).

Q. What about falling leaves?

Falling leaves are hard on a pond. If left in the pond, they will decay and add to the ammonia load. They can also make the water too acidic. Put leaf netting over your pond for the weeks when most leaves fall into the pond. Pond netting or no pond netting, you will still need to scoop the leaves off the surface and the bottom with a long-handled net.
Netting is available at your local pond retailer. If you have a small pond, you can drape the netting over the pond and anchor it around the perimeter with rocks. It is advisable to have some type of support in the middle to keep the netting from dipping into your pond when leaves accumulate. For larger ponds, a strong plastic coated wire, such as a dog run cable, can be strung between two trees or from posts on either end of the pond, with the netting draped over it to form a tent.

Q. When should I do a big clean-out?

Doing a “big clean-out” should be done in both the fall and the spring.

Fall Big Clean

It is good to scoop out as much of the leaves and sludge as you can before winter. You may want to pump some of the water out of the pond to expose the planting shelves around the pond periphery. This will make it easier to hand-remove leaves that have adhered themselves to the pond edges and shelves. Using a hose nozzle, blast off the accumulated debris and sludge around the pond shelves and edges, and then remove remaining debris with a net or pond vacuum. When replacing the water, be sure to treat the chlorine and chloramines with a water treatment product such as TetraPond AquaSafe®.

Spring Big Clean

In the spring, you’ll need to clean out the leaves that have blown into your pond over the winter months. Follow the basic “Fall Big Clean” procedures.

Q. Should I keep my pump and waterfall running in the winter?

Keeping your pump running year-round depends on the severity of the winter.
If you are expecting a period of cold weather that will freeze your waterfall, you should not run your pump and waterfall. It is possible for the waterfall to freeze in such a way that the water will exit and eventually drain the pond.

If you decide to run your pump throughout the winter, it is advisable to raise the pump closer to the surface. This will minimize the mixing of colder water at the pond bottom with the warmer water closer to the surface, which could adversely affect your fish. (See "Will my fish be OK in the pond over winter?") If your pond is prone to freezing in the winter, use a pond de-icer. It probably won’t be necessary to run your pump.

Q. Will my fish be OK in the pond over winter?

In most parts of the U.S., it is fine to keep your fish in your pond, providing the depth of the pond is adequate. For most parts of the US, 18 inches depths are sufficient. Koi, Shubunkins and most goldfish survive winter by staying inactive at the bottom of the pond where the water remains a constant cold temperature. Circulating the water during the winter will cause fluctuations in the water temperature and may adversely affect fish in their state of hibernation.
Be sure your pond has areas that are deep enough so it does not freeze to the bottom. Generally 18 inches depth is sufficient, but ponds in extremely cold regions of the country should have areas 30 inches deep or deeper.

Use a pond de-icer to keep an area of the pond ice-free to allow toxic gases to escape.

Some fish, such as fancy goldfish, should be brought indoors during the winter. Check with your local fish dealer for advice on your specific fish.

Remember, do not feed your fish when water temperatures are below 39o F. (See Fish Care questions about changing the diet during colder months.)

Q. Do I need a pond de-icer?
A pond de-icer is essential for fish survival if you live in an area where your pond freezes over.
A pond de-icer will leave a small area of the pond ice-free, which will allow harmful gases that would otherwise be trapped beneath the surface, to escape the pond. Be aware that using pond heaters with high wattage (over 500 watts) can be very expensive to operate.

Q. Could I leave my UV clarifier out during the winter since it is plumbed into the system?

It is better to bring your UV clarifier indoors before freezing temperatures arrive. There is no need to run the UV during the winter. Water inside the UV clarifier can freeze, expand and damage the quartz sleeve, bulb, housing or electronics.

Q. Should I feed my fish during the winter?

Do not feed your fish when water temperatures are below 39o F.
Feed wheat-germ based foods such as TetraPond® Spring & Fall Diet when water temperatures are between 39o F and 50o F.

See the FAQ section on Fish Care for more detailed information.

Q. When do I stop feeding my fish?

Stop feeding when water temperatures fall below 39o F. Even if your fish are not moving around or seeking food, and the water temperature rises above 39o F during the winter months, do not feed them.