How to Winterize a Pond and Protect Your Fish During the Cold Season

Prepare your pond to withstand cold weather with a simple winterization process

Backyard pond with stones.
Photo: Ian Tuttle / Angi
Backyard pond with stones.
Photo: Ian Tuttle / Angi
Breyden Kellam
Written by Breyden Kellam
Contributing Writer
Updated May 12, 2025
SKILL LEVEL
Simple
COMPLETION TIME
3 hours
COST
$0-$25
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What you'll need:
TOOLS
  • Pond gloves
  • Waders
  • Pruning tools
  • Aerator
  • De-icer
SUPPLIES
  • Cold water bacteria
  • Garbage bags

If you want to enjoy a vibrant pond in the spring, it’s essential to prepare it to stay healthy during the winter season. Unsure of how to winterize a pond? We’ve got you covered with this helpful how-to guide on winterizing a pond for best results.  

Prepping to Winterize Your Pond

Before it’s time to winterize your pond, there are steps you can take to make the process easier. For example, putting a pond net over your pond before autumn leaves start to fall will make for a much lighter cleaning later on. You could also fill your pond with types of plants and fish that can easily survive in the winter. This step will save you even more time during winterization.

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  1. Clean the Pond

    A young man cleaning the house pond
    Photo: suravikin / iStock / Getty Images Plus / Getty Images

    First, you’ll want to remove any fallen leaves and debris from your backyard pond. Otherwise, they could decay and release harmful gases that can kill fish and other wildlife. Use a pond net to remove any floating leaves from the surface, and then remove any debris from the bottom of the pond.

    If you installed netting, this should be a fairly quick process. Simply remove and discard leaves or debris from the netting, and store the net away in a dry place. Make sure to check the pond for any leaves or debris that the net didn’t catch.

  2. Clean Pump and Filter

    If you plan to shut down your pond for the winter, the next step is to turn off your pump. Detach the pump from any plumbing or water source and allow the water to drain out. Then, take a cloth and clean any debris off your pump. Do the same for other equipment, such as the filter media and UV clarifiers. It’s best to store your pump in a bucket of water to prevent drying and cracking. Lastly, store your equipment away in a dry place that will not freeze.

  3. Trim Dead and Dying Plants

    A woman trimming plants off the pond
    Photo: suravikin / iStock / Getty Images Plus / Getty Images

    Like decaying leaves, dying plants can harm your pond’s health. Use pruning tools to remove any dead or dying foliage down to the base of your pond plants. You’ll need to discard plants that cannot withstand winter temperatures or bring them indoors.

  4. Install Aerator and De-Icer

    Keeping an aerator in your pond over the winter will ensure proper oxygen levels and prevent harmful gases from being trapped underneath the ice. A de-icer keeps a hole open in the ice, making sure that fish can survive.

  5. Add Cold Water Bacteria

    Bacteria isn’t always a bad thing. In fact, adding cold water bacteria to your pond can ensure that it stays clean and healthy during the winter months. Designed for low temperatures, cold water bacteria will keep debris at bay and minimize the maintenance you’ll have to do on your pond when spring rolls back around.

  6. Prepare Your Fish

    A man observing the fish in the pond
    Photo: Peter Carruthers / iStock / Getty Images Plus / Getty Images

    Before your pond fish go into hibernation, you’ll want to ensure they’re healthy. As water temperature drops, so does the metabolism and digestion of your fish. Before temperatures fall below 50 degrees Fahrenheit, switch your fish to a cold-weather food and gradually reduce the times per week and amount you feed your fish. Then, stop feeding your fish entirely once the temperature is below 50 degrees.

DIY vs. Hiring a Pro

Generally speaking, winterizing a pond is a simple and inexpensive process that most homeowners should be able to do themselves, but it will take a few hours of your time. If you have a busy schedule, you can always hire a pond cleaning pro to get the job done. Pond cleaning professionals may charge anywhere from $100 to $500 to winterize your pond. Your final cost will depend on location, materials needed, and the scope of the work.

Frequently Asked Questions

Even if you empty your pond before the winter, there’s a good chance it will refill naturally. It’s ideal in most cases, then, to leave water in your pond and winterize it instead. This method will prevent ice damage and protect wildlife. Plus, it’ll lessen the steps required to reopen your pond in the spring.

When deciding whether or not to turn off your pump, you should consider your area’s climate and the aquatic life in your pond. If you live in an area with freezing winter temperatures and don’t have any wildlife, keeping your pump on could damage it. If you have aquatic life but live in a colder climate, you might consider keeping your pump running and adding a pond heater.

Yes, your fish should stay alive in a frozen pond if you winterize it properly. By ensuring your pond has enough oxygen, good water quality, and a hole to release harmful gases, your pond and fish have the best chance of staying alive and healthy. However, if you have tropical fish, they should be overwintered indoors.

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Learn more about our contributor
Breyden Kellam
Written by Breyden Kellam
Contributing Writer
Breyden is passionate about writing for the cost-conscious homeowner who wants to update their space for maximum enjoyment. When she isn’t reading up on the latest home design trends, she can be found looking for creative ways to spruce up her own space.

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