Preparing Your Pond for Winter in the Fall

Fall is the perfect season to spend time outdoors in the crisp cool air.  It also happens to be the ideal time to get your pond ready for winter.  There are a lot of steps to ensure that your pond survives the winter conditions so we’ve come up with some guidelines to help you prep for the cold weather to come. 

A good place to start is to perform a water test, including oxygen level, which will help to determine what current conditions exist and to help examine the factors that contribute to them. You will also be able to create a plan of attack to combat the poor conditions in your pond and figure out the next steps that are needed.  These can range from partial water changes, clearing debris, cleaning filters, using additives, or aeration, which all happen to be essential to the winterization of your pond.

Water temperature is an important aspect to gauge when it is best to make changes that will help the overall health of the pond.  Having a thermometer will help you determine at what point during fall to start different preparations.  Generally, doing partial water changes is always a good idea during fall to help rid your pond of murky water.  A good rule to follow is executing a 50% partial water change before the water temperature goes below 60°F.  Remember to use a water clarifier or barley pond clarifier to keep your water clean and clear and a chlorine remover if your tap water contains chlorine or chloramines.

Cleaning your pond is one of the most crucial steps in winterizing your water garden and should be done before the water temperature falls below 50°F.  This is suggested since the fish will still be active and less likely to suffer injuries during cleaning.  Ridding your pond of leaves and plant debris will help to avoid the break down of any remnants over the winter, which can cause a spike in harmful ammonia levels.  Clear debris by scooping up fall leaves from the surface with a fine net. During the partial water change, prune your marginal pond plants and remove floating plants to a safe place before they decay.  Deep-water plants, like lotus and lilies, can be placed in the deepest part of the pond.  Floating plants, like Water Hyacinths or tropical lilies, should be removed from the water and stored in warm, frost-free conditions, like inside the home, until the following year.  Once the plant shelves and bottom of the pond are clear you can remove the remaining leaves that are stuck by hand.  You can use a pond vacuum and hose to remove the remaining debris and sludge from the bottom of the pond.  To help avoid any more debris from entering your pond, we recommend covering your pond with netting and keeping the area around the pond raked.  If necessary, use an additive like pond cleaner tablets to help accelerate the decomposition of leaves, scum, sediment, and other pollutants to keep a healthy balanced ecosystem. This will also help to make sure your pond is healthy when you reopen your pond in spring. 

Cleaning your filters is important because a dirty filtration system is inefficient. It works harder, accomplishes less, and may clog and not work at all. Use this opportunity to clean everything, replace media if needed, and make sure it is in perfect working condition. The same goes for your pumps, UV clarifiers, and aerators.  Make sure they are drained, cleaned, and the features are working in top condition.  Fix or replace any non-functioning pieces.  Replace the water in your pond and use any additives mentioned above to ensure the water is healthy.  Retesting the water will ensure everything is in good balance and ready for the winter conditions. 

Once water temperatures drop below 40°F, it’s time to remove or make sure your equipment is in the right position for the cold weather.  If you have mild or moderate winter temperatures, you may continue to run the pumps and filters but it is recommended to shut down the pond to avoid freezing.  Cold water holds much more oxygen than warm water and the fish’s respiration and activity are slow so there is a lesser need for circulation and aeration.  Also, running the pump on the bottom of the pond can introduce cold water to the deeper levels making a temperature that is too low for fish to survive.  The bacteria in your biological filter does not work in cold water so the only reason to keep the water flowing through your biological filter is to keep the bacteria alive for the following spring reopening.  The benefit of keeping beneficial bacteria alive is to ensure good water quality early on in spring.  Be sure to shut down any above ground water sources such as fountains or waterfalls during winter so freezing does not occur.  It is recommended to store equipment indoors safe from the elements. We suggest placing the pump, if it is submersible, in a bucket of water to keep the moving parts and seals wet.  If you decide to store the equipment outside or in an unheated space make sure that there is no water left in the device that may ice up and cause the body or housing to break.

Purchasing a floating deicer is recommended to keep an area free of ice.  This opening is necessary during periods where ice is covering the surface to allow an exchange of gases.  If these gases build up and do not have a place to escape they can be toxic to fish.  A deicer creates this space for gas exchange, but as an alternative you can melt a small hole daily by putting a heated pan of warm water on the surface.  Both methods create an ice-free opening and will let pond dwellers breathe, maintaining their health and longevity.

Following these suggestions will help to maintain a healthy pond ecosystem through out winter and make your spring preparations easier.  This will ensure that you will have high quality water faster when the pond reopens so you can relax and enjoy your pond all season long.