When the temperatures in New Jersey start dipping below freezing, your backyard pond needs a seasonal shift. One of the most common questions we get as fish pond builders in Union County is: “What pond equipment do I leave running, and what should I shut off for winter?” Getting this balance right keeps your fish safe, your equipment protected, and your pond healthy until spring.

Let’s break it down.

Equipment You Should Shut Down for Winter

Here’s what you’ll want to shut down to avoid costly damage and water loss:

Waterfall Pumps

Your waterfall might be the showpiece of your pond in summer, but in winter it can actually cause problems. Running water over rocks in freezing conditions creates ice dams. These dams can divert water out of the pond and drain it dangerously low.

Best Practice:

Shut off your main waterfall pump.
Drain and store it somewhere frost-free.
If you have plumbing that can’t be drained, use compressed air to blow out excess water.

External Filtration Systems

Large pressure filters or bead filters aren’t designed to handle freezing. Ice inside the canister or pipes can crack housings, leading to costly springtime repairs.

Best Practice:

Disconnect and drain filters completely.
Store filter media in water inside a garage or basement so beneficial bacteria survive until spring.

UV Clarifiers

These are unnecessary in winter. Cold water naturally suppresses algae growth, and the UV bulbs are better off stored safely until you restart your system.

Equipment You Should Keep Running in Winter

While some gear should be packed away, other equipment is vital to keep your pond’s ecosystem stable and your fish safe.

Air Pumps / Aerators

Aeration is one of the most important tools for winter survival. As ice forms across the pond, it can trap harmful gases below. An air stone bubbling near the surface creates a hole in the ice and keeps oxygen levels safe for your fish.

Pro Tip: Don’t place the air stone at the deepest point. Instead, position it halfway down the water column so you don’t chill the warm refuge where your koi and goldfish rest.

Pond Heaters (De-Icers)

A floating pond de-icer doesn’t heat the whole pond, it just maintains an opening in the ice. This small opening allows toxic gases to escape and fresh oxygen to enter. Even if you’re running an aerator, a backup de-icer gives peace of mind during heavy freezes.

Low-Flow Circulation Pumps

In some setups, keeping a small pump running near the surface helps circulate water and prevent complete freeze-over. This is optional, but if you choose to use one, keep it shallow so it doesn’t disturb the deeper warm zone where fish overwinter.

Why Proper Shutdown Matters

Shutting down the wrong equipment, or failing to shut down anything at all, can cause serious issues, like:

Cracked pipes and ruined pumps
Dangerous water loss from ice dams
Stress or suffocation for your fish

At Atlantis Water Gardens, we’ve helped countless homeowners avoid these headaches. With more than 20 years of building and maintaining world-class ponds across New Jersey, we know firsthand how a little winter prep protects your investment long-term.

Let’s Get Your Pond Prepared for Winter!

If you’re unsure about your setup, reach out Atlantis Water Gardens. We’ve winterized thousands of ponds, and we can make sure yours weathers the cold without a hitch.

What Winter Pond Equipment Should Be Shut Down?