A frozen over pond means the water below the ice is completely cut off from the air above. This means that the water can’t absorb any new oxygen.
And it also can’t release any toxic gases that build up due to plant decay or fish respiration. This makes a quality de-icer essential.
In this guide, I’ll teach you how to choose a pond de-icer and review 5 of the top choices to give you the number one best pond de-icer.
Overview: Top Choices
Best de-icer for small ponds is the Danner Manufacturing.
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
Best de-icer for medium size ponds (under 1000 gallons) is the Laguana Power Heat.
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
Best de-icer for large ponds is the Farm Innovators.
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
What Does a Pond De-Icer Do?
A pond de-icer heats up and prevents ice from forming in a circle around its immediate area.
A de-icer is not meant to keep the pond ice free.
However, the hole they create in the ice lets oxygen in and CO2 out, keeping your fish alive.
A de-icer is different from a heater in that it’s not meant to keep all of the water in the pond above freezing. It just keeps the water right around the unit from icing over.
Pond de-icers are not meant to melt through ice that’s already covering the pond. They’re meant to start off in water and keep a hole clear.
If your pond already has a thick layer of ice, boil a pot of water and slowly (and carefully!) pour it onto the ice until you clear a hole big enough to place the de-icer in so that it touches the water.
Don’t just place the de-icer on an already frozen pond and hope it melts through.
Pro Tip: If you want to maximize oxygen levels in your pond, place an aerator in your pond as well.
An aerator constantly blows fresh oxygen into the water and the water movement from the bubbles will also open up a hole in the ice.
Place the aerator well away from the de-icer so it doesn’t disperse the heat.
What to Look for When Choosing a Pond De-Icer
Safe for Plastic Liners
Some pond de-icers can melt plastic pond liners if they accidentally touch.
If the outer edge of the de-icer heats up enough, and it then touches the pond lining, it’s even possible for it to melt a hole completely through the liner causing a leak.
It’s important to verify that the unit you choose is safe for lined ponds in order to avoid ruining your pond.
Wattage and Pond Size
The biggest factor for choosing a pond de-icer is the wattage versus the size of your pond.
Bigger ponds need a higher wattage de-icer. It’s harder to overcome the higher volume of cold water in a bigger pond, so you need a more powerful de-icer.
Watts Per Gallon for Pond De-Icers
- Up to 150 gallons (567 liters): 100 watts
- Up to 250 gallons (946 liters): 250 watts
- Up to 500 gallons (1,892 liters): 300 watts
- Up to 1,000 gallons (3,785 liters): 750 watts
- Up to 1,500 gallons (5,680 liters): 1,250 watts
- Up to 2,000 gallons (7,570 liters): 1,500 watts
Keep in mind that all of these wattage to pond size estimates assume that you live in one of the colder agricultural zones. You may be able to get away with a smaller wattage if you live in a warmer zone.
Pro Tip: Running a de-icer can really increase your electric bill, especially a 1,250 or 1,500 watt model.
Thermo Cubes can really help with this. They’re power outlets with their own internal thermometers. The Thermo Cube will turn on power when the air temp hits 35°F (1.7°C) and will shut off again once the temp rises to 45°F (7°C).
This ensures the de-icer only draws power when it’s needed and can help cut the cost of running it all winter.
5 Best Pond De-Icers Reviewed
1. K&H Thermo-Pond Floating Pond De-Icer 3.0
Key Features:
- Pond liner safe
- 100 watts
- Thermostatically controlled to prevent overheating
- 12 foot (4 meter) cord
The K&H Thermo-Pond De-Icer is a great low wattage solution for small ponds that are 150 gallons or less. The unit is black and disc-shaped with a small dome on top, it kind of looks like a flying saucer.
The cord is 12 feet long and does not need to be plugged into a GFCI outlet.
This de-icer is pond liner safe and has an internal thermostat that shuts the unit off if it gets too hot. This is a great feature that will keep the de-icer from overheating if it is removed from the water.
But, you’d need to add a Thermo Cube to stop it from running constantly.
Pros:
- Thermostat prevents overheating
- Perfect for smaller ponds
Cons:
- Cord could be longer
- Internal thermostat only keeps unit from overheating, doesn’t switch on/off otherwise
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
2. Danner Manufacturing 2175 Pond De-icer (best For Small Ponds)
Key Features:
- Pond liner safe
- 120 watts
- Thermostatic control turns it on/off based on temperature
- 18 foot (6 meter) cord
- 1 year limited warranty
This Pondmaster de-icer is cylindrical with a lip around the top edge and a small dome on top.
It only comes in bright red and some users complain it’s a bit of an eyesore in the pond.
At 120 watts, it’s great for small ponds but really isn’t suitable for anything over 150 gallons.
It has a built in thermostat that turns the de-icer on when temps get near freezing and then turns the unit back off when temperatures warm up. This makes it more energy efficient without having to add a Thermo Cube.
There’s no need to try and adjust settings, just place the unit in the water and plug it in.
Pros:
- Internal thermostat controls makes unit more energy efficient
- Long 18 foot cord
Cons:
- Red color really stands out
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
3. Aquascape 39000 Pond Heater and De-icer
Key Features:
- Pond liner safe
- 300 watts
- Stainless steel construction
- 22 foot (7 meter) cord
- LED light indicates when unit is running
The Aquascape 39000 is a 300 watt heater suitable for ponds up to 500 gallons.
The outer shell is constructed from stainless steel that helps prevent cracking and corrosion.
The top of the unit looks a bit like a hat with a flat top and brim around the edge.
An LED light on the top indicates when the unit is plugged in. It glows red when the heating element is running. If the unit is taken out of the water and starts to overheat, the element will turn off and the LED will switch to blue.
The thermostat will only switch off when the unit gets up to 70°F. To make it more energy efficient, you’d need to add a Thermo Cube so that it would turn on at 35°F and back off at 45°F.
One awkward thing is that the power cord comes out of the bottom of the de-icer. This can lead to the unit sitting at an angle in the water. The placement of the cord can make it more difficult to position the de-icer in your pond.
Also, the manufacturer recommends that this de-icer be plugged into a GFIC outlet, so you may need to get one installed by an electrician.
Pros:
- Stainless steel construction is durable
- LED indicator tells you element is working
- Thermostat keeps it from overheating
- Great for ponds up to 500 gallons
Cons:
- Cord is in a weird position
- Needs a Thermo Cube to be energy efficient
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
4. LagunaPower Heat 500 Watts (Best For Medium Sized Ponds)
Key Features:
- Pond liner safe
- 500 watts
- Thermostatic control turns it on/off based on temperature
- LED indicator tells you heating element is on
- Stainless steel construction
- 18 foot (3 meter)
The Laguna Power Heat is another stainless steel de-icer that looks like a flying saucer from War of the Worlds.
It’s thermostatically controlled so it only heats when you need it to. An LED indicator on top will let you know when the element is running.
This is a 500 watt unit that’s good for ponds between 500 to 750 gallons.
For safety, you should use a GFCI outlet with this de-icer.
This model is another example where the cord comes straight out of the bottom. This can lead to it tilting in the water unless you weigh the cord down.
Pros:
- Tough stainless steel construction
- Internal thermostat controls makes unit more energy efficient
- LED lets you know it’s running
Cons:
- Requires GFCI outlet
- Awkward cord placement
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
5. Farm Innovators Model H-418C (Best For Large Ponds)
Key Features:
- Pond liner safe
- 1,250 watts
- Cast aluminum construction
- Thermostatically controlled, only runs when needed
This de-icer from Farm Innovators is much more powerful than the other models I’ve covered so far. It’s 1,250 watts, so it has enough juice to work for ponds up to 1,500 gallons.
The base of the unit is a large ring made from cast aluminum which is very sturdy.
The power cord comes directly out of the bottom of the base, which can make it sort of awkward to place. The cord is covered with an “anti-chew” protector since this de-icer is also used in water troughs for livestock.
The top of the de-icer is made up of a tough plastic dome that works as a float to keep the unit at the surface.
It has an internal thermometer that controls the heating element so it only runs when needed. Even so, running the higher wattage means you can see a noticeable increase in your electric bill.
Pros:
- Powerful enough for ponds up to 1,500 gallons
- Thermostat runs de-icer only when it’s needed
Cons:
- Even with thermostatic controls, 1,250 watts can really add up on the electric bill
- Awkward cord placement
- Definitely need a GFCI outlet for this big boy
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
Which is Best?
Deciding on which de-icer is best for your pond should be based mostly on what size pond you have and the features you want.
The larger your pond is, the more juice it takes to fight the cold and keep a hole open in the ice.
For smaller ponds, the Danner Manufacturing de-icer has the right wattage and also some nice features like the internal thermometer that shuts it on/off when the weather gets warmer and colder.
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
For medium sized ponds under 1,000 gallons, the Laguna Power Heat is a good choice. It’s got the tough stainless steel construction, thermostatic control and the LED indicator light.
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
The Farm Innovators de-icer is the best choice for large ponds. I’m not crazy about the fact that it doesn’t have an LED indicator, but the cast aluminum base should be good and tough.
Last update on 2024-04-26 / Commissions Earned / Images from Amazon Product Advertising API
Keeping an airhole open in the ice is so important for your fish’s survival. No matter what model of de-icer you go with, remember to check periodically to make sure it’s working.
