How to Prepare a Pond for a Freeze: Pump, Fish, and Cover FAQs
Freezing weather is a yearly concern in much of the country. Here are answers to the most common questions about getting your pond through a freeze.
Closing your pond for the season? Follow our step-by-step closing guide. Expecting just a quick cold snap? See what to do during a short freeze.
Quick Answers
- Pump: If your pond freezes solid, shut it down and bring it indoors. Otherwise, keep it running and turn off waterfalls and nozzles.
- Fish: They can usually stay if your pond is deep enough and you keep an opening in the ice.
- Feeding: Stop when the water reaches 50°F.
- UV clarifier: Bring it indoors before the cold hits.
- Covering: Skip the tarp.
Should I Shut Off My Pump?
It depends on how hard your pond will freeze.
- If your pond will freeze solid: Close it down. Unplug your equipment and bring pumps and filters indoors. Store the pump in a bucket of water in a spot that won't freeze. See the full closing steps.
- If your pond will freeze only at the surface: Keep it running for your fish and plants, but stop powering any waterfalls and nozzles.
- If you expect only a brief drop in temperature: Keep your pump running and turn off waterfalls and nozzles. It takes a lot to freeze an entire pond, and moving water can help keep it from freezing in many situations. See what to do during a short freeze.
Have a UV clarifier? Bring it indoors before temperatures drop. The water inside can freeze and damage the system.
Can I Leave My Fish in the Pond?
Most of the time, yes. Even if your pond looks frozen on top, a deep enough pond likely isn't frozen at the bottom. Most pond fish, like goldfish and koi, can still thrive in a frozen pond. They stay at the bottom, relatively inactive, and go into hibernation. This may not apply to every fish, so ask your local fish dealer if yours need to come inside below a certain temperature.
- Depth matters: Fish are only safe if your pond is deep enough. The average is 18 inches, but colder parts of the country may need as much as 30 inches. See how pond depth affects a short freeze.
- Keep an opening: Keep part of the surface from freezing so toxic gases can escape. Use an aerator or de-icer. If the pond freezes over, pour boiling water on one spot to melt an opening. Learn more about preventing toxic gases in your pond.
- Never break the ice: The noise can shock your fish and seriously harm them.
- Stop feeding at 50°F: Fish slow down in cold water and are preparing to hibernate.
Should I Cover My Pond?
Skip the tarp. Sunlight needs to reach your plants and fish, and a cover can keep toxic gases from escaping. Light and air are important for a healthy pond, and covering it can do more harm than good.
Still Have Questions?
The pond boss® team is happy to help. Contact us or browse our FAQ.
