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How to Winterize a Pond: Fall Pond Care

It's important to know how to winterize a pond and prepare fish to withstand the harsh winter. Over the course of a year, your pond will accumulate debris and organics such as leaves, twigs, grass clippings, and fish waste. Left unchecked, decaying debris can release toxic gas and reduce oxygen levels. Removing this debris and replacing filtration systems with aeration kits and de-icers will help ensure oxygen levels stay as high as possible and provide aeration, ventilation, and circulation throughout the winter months.

In this guide, we'll walk through a step-by-step approach to winterize your pond and provide the best fall pond care.

Step 1: Prepare for Shutdown

Once all the leaves have fallen, begin your fall pond care by removing any netting. Pond netting should be stored indoors to keep it safe from wear and tear due to heavy snowfall and ice.

Next, access your pump and filter for cleaning and storage. For ponds with waterfalls and skimmers, disconnect your pump and check valve, and allow the water to drain from your plumbing and waterfall.

For ponds with in-pond filtration or filters containing UV or ion clarifiers, disconnect them from the plumbing and drain out the water.

Step 2: Lower the Pond's Water Level

Now that your filtration system and pump have been disconnected, use a submersible pump and drain hose to lower the pond level below the opening of the skimmer.

Next, winterize your pond waterfall or skimmer box by pumping out the water. While it is not necessary to remove them from the pond, water should be drained from them to prevent cracking as the water freezes and thaws throughout winter.

For ponds that do not contain skimmers, it is not necessary to lower the water level in your pond.

Step 3: Clean Filters, Media, and Pump

Filter Media

First, wash the filter media pads and bio balls located in your skimmer, waterfall box, pressurized filter, and/or in-pond filter. Filter media may be stored in the waterfall box or skimmer or kept inside for the winter.

If any of the media looks worn or torn, start a list for items to be replaced during spring start-up.

UV Clarifiers

For UV clarifiers, disassemble the unit and clean the quartz sleeve with a soft cloth and a descaler such as white vinegar or D-Scale.

A UV bulb's effectiveness degrades over time and should be replaced after each season. You may choose to replace the UV bulb in preparation, or you can add this task to your spring checklist.


Now it's time for your pump. Clean excess debris off your pump, then inspect for wear and tear or any damage like worn impellers.

When storing your pump and preparing your pond for the winter, we recommend placing it in a bucket of water to prevent the seals in the pump from drying and cracking during storage. Keep the pump, in-pond filters, and UV clarifiers in a location that will not freeze, like your basement.

Step 4 - Trim Back Aquatic Plants

As winter approaches, plants will naturally fall into a dormant state. To winterize hardy plants, use your pruning tools to trim off dead foliage just above the soil.

If your plants are in pots, move the pot to the pond's bottom to protect the roots from freezing temperatures. Tropical water lilies, floating plants, or other temperature sensitive varieties will either need to be discarded or brought indoors.

Step 5- Remove Excess Debris

Rotting leaves, twigs, or dead aquatic plants will put stress on your pond's oxygen levels throughout the winter, which puts your fish at risk. Remove leaves and debris from ponds and streams with the help of a hand net. If you have hard to reach small debris, use a vacuum like the ClearVac to make cleanup easier.

Step 6 - Install Aeration Kit & De-Icer

Aeration and de-icers help to keep a hole open in the ice during winter months. This prevents harmful gases from being trapped under the ice and allows oxygen levels to stay saturated in the pond.

If you don't have one, we recommend installing an aeration kit, such as The Pond Guy Pond Aerator, in the shallow area of your pond.

If you already have one installed, simply relocate air stones or diffusers to the shallower part of the pond. This will leave an undisturbed area at the bottom of your pond for your fish to gather for the winter. For added protection, consider installing a pond heater to ensure a hole stays open in the ice.

Step 7 - Switch to Wheatgerm Fish Food

If you haven't already, now is the time to switch your fish to a wheatgerm-based diet. Wheatgerm food, such as The Pond Guy Spring & Fall Fish Food, is easier to digest in cooler temperatures and will sustain your fish until they are dormant.

When water temperatures fall below 50°F, reduce feedings to three times per week and only feed your fish what they can consume in a five minute period. Once water temperatures drop below 40°F, stop feeding your fish entirely until spring.

Step 8 - Add Seasonal Defense

Bacteria is the final key to garden pond winter care. Even with a thorough cleaning, some debris will remain in your pond. Cold weather bacteria, such as Seasonal Defense Spring & Fall Prep, should be used until water temperatures fall below 40°F. Seasonal Defense will further break down any remaining debris through the cooler part of the season and will give you a head start on spring pond management.

Helpful Tools and Equipment for Fall and Winter Pond Care

Follow the steps above to take your backyard pond winter care to the next level. To help you as you go, here's a summary of all the tools and equipment we mentioned.

To Keep You Dry:

For Draining & Cleaning:

For Jumpstarting Biological Filters:

For Winter Preparation: