An iced-over pond is a beautiful sight to behold.
The frozen water creates a soft glaze over napping fish, icicles sparkle near the waterfalls and - if you're lucky - some light snow might blanket everything in a soft cloud of white.
Gazing out over the ice is one of the best parts of owning a pond in winter. But you need to keep a small opening so your fish can breathe.
That's where a pond de-icer comes in.
A pond de-icer is a small device that floats on the pond's surface, keeping a small hole open in the ice. When used in addition to an aerator, a pond de-icer is a perfect tool for keeping your fish happy and healthy until spring.
In this Guide: Pond De-icers 101
- How Do Pond De-icers Work?
- Pond De-icers vs. Pond Heaters
- Do I Need a Pond De-icer?
- What is the Best Pond De-icer?
- How to Install a Pond De-icer
- Troubleshooting Your Pond De-icer
How Do Pond De-icers Work?
De-icers float in your pond and keep a hole open in the ice, letting bad gases escape out of the pond. These gases - which come from exhaling fish and decomposing debris - would otherwise build up under the ice and suffocate your pond life.
A de-icer will heat up just enough to form a small opening in the ice; it will not cause a significant increase in your pond's overall temperature. That means your fish will still enter torpor as the temperatures drop, and parts of your pond that aren't close to the de-icer will still freeze over - which is OK!
Remember: always run an aerator in addition to a de-icer. While you can sometimes run an aerator without a de-icer, we don't recommend running a de-icer without an aerator.
Pond De-icers vs. Pond Heaters
A lot of new pond owners think they want a pond heater. Most actually want a de-icer.
A true heater raises the overall temperature of the pond, keeping it springlike year-round.
You probably don't want a pond heater. (Unless you're trying to keep tropical fish outdoors and really know what you're doing.)
Fish like koi, goldfish and catfish enter a state called torpor when the water temperature drops, just like their wild counterparts. This state of near-hibernation is natural. Your frogs, turtles and other pond life have similar ways of surviving the cold.
Do I Really Need a Pond De-icer?
Whether or not you need a pond de-icer depends on the climate and how closely you want to keep an eye on your pond.
Many pond owners can keep a hole open in the ice by simply running an aerator near the water's surface. The bubbles not only infuse your water with some much-needed oxygen but also prevent ice from forming in that area. A running waterfall can do the same if you choose not to winterize your pond.
A pond de-icer is nice to have as back up. It will give you peace of mind knowing your fish won't suffocate if the aerator fails. It also provides a safeguard during extreme cold, when the aerator or waterfall might not be enough to ward off ice.
What is the Best Pond De-icer?
We recommend this 300-Watt stainless steel pond de-icer.
The 300 watts of power are just enough to keep a hole open in the ice without wasting electricity, and the stainless-steel design makes it sturdy and weatherproof.
This de-icer also has a handy indicator light that turns red when it's warm or heating and blue when it's cool or not heating.
How to Install a Pond De-icer
These instructions are specific to our pond de-icers but could apply to other kinds too:
STEP 0: BE SAFE
You're going to be working around ice, water and electricity, so use common sense.
Make sure your de-icer's cord isn't damaged. Don't use extension cords. Unplug the de-icer before removing it from the pond. Be careful walking around ice.
STEP 1: PLACE DE-ICER IN POND
Float the pond de-icer in a deep part of the pond or directly over a running aerator.
The manufacturer recommends leaving the de-icer in the pond for about one hour before plugging it in. Doing so lets the unit calibrate to the water temperature.
If the ice is completely frozen, lay the de-icer on its side and let it slowly melt through the ice. You might need to turn the de-icer upright as it starts to melt through the ice.
Be patient when waiting for ice to thaw. It might take several hours for the de-icer to completely melt through. Never break the ice with force; the shock will stress fish and could seriously hurt them.
STEP 2: PLUG IT IN
Plug the electrical cord into a GFI-regulated power receptacle.
The indicator light on top of the de-icer will turn red when it's warm or heating and blue when it's cool or not heating.
STEP 3: STORE IN SPRING
When the pond is no longer at risk of freezing over, remove the de-icer from the pond and store it.
Unplug the de-icer and let sit in the pond for at least one hour before removing so it has a chance to cool down.
The manufacturer recommends cleaning the stainless-steel surface before storing. You can use a mild acid, like white vinegar, and then rinse thoroughly with clean tap water. This process will remove calcium deposits that might otherwise impede the thermostat from working correctly.
Troubleshooting Your Pond De-icer
Something not working right? Check these things first:
- Is the de-icer plugged in correctly?
- Is the GFI-rated receptacle or ground fault
interrupter operating properly?
Still not working? Check to see if the LED light on the top of the unit is red. If it's red, that means it's heating.
If the indicator LED light on top of the unit is blue, the heater is in off mode and not heating.
The LED indicator light and thermostat is a safety function to prevent accidental burns. If not functioning correctly, you might need to reset the thermostat by unplugging the heater for about an hour to let it completely cool.
When you plug in the heater, the LED indicator should turn red, indicating heating.