Top 5 Best Pond Heaters & De-Icers For Small Ponds

In this article, we’ll review five of the best pond heaters and deicers for small ponds that you can use through the winter to ensure your fish can breathe well and prevent the water from becoming toxic.

Pond keeping is very different than owning a fish tank. Ponds require water treatments, fountain pumps, waterfall kits, protein skimmers, weed control, predator control, and more.

To make things worse, most pond kits do not come with the tools your pond needs to withstand the seasons, mainly winter.

Some winters can last months on end, and if you can provide a little bit of warmth by using a pond winterizing kit or by using floating pond deicers and heaters, it will ensure they survive until the spring thaw.

Before we get into it, here are a few of my favorite options.

Pond Heaters & Deicers To Keep Your Small Pond Warm All Winter

How Do You Heat A Small Pond?

If you have Goldfish and Koi in your pond over winter or even more delicate tropical fish inhabiting your pond, it must be heated. The simplest way is to use an in-line electric water heater, also called in-line electric Koi Pond heaters. These heaters are mainly used for larger Koi ponds. They need to be set up with the pond pump, as they heat the water while it’s being fed back to the pond. While this is the most effective pond heating method, it’s also the most expensive option. Since it’s supposed to heat the entire body of water, it needs to pull a lot of electricity to get the job done. A general rule of thumb is that to get a 10-degree increase in temperature in a 1000 gallon pond, and the heater will need 1 watt per gallon. For smaller ponds, you may get away with less wattage per gallon to get the same 10-degree increase.

You can do a few things to mitigate the electricity consumption (and your electricity bill), like insulating your pond or partially covering it up. Make sure you don’t cover it up completely, as it will prevent the gas exchange from the pond’s surface to the atmosphere. The result will be low oxygen diffusion and the build-up of harmful gases in the pond. But partial surface coverage and insulating the pond from the inside can take some burden off your pond heater.

Another way to heat the water is to use submersible or immersed heaters, the kind you might use in an aquarium. But the catch is that no matter how powerful the heater is, it can’t raise the temperature of the whole pond beyond a few degrees. However, it can create a “hot pocket,” a small region where the temperature of the water is significantly higher near the heater. The farther your fish move away from this region, the colder the water would be. It’s usually preferable for ponds that are between 300 to 500 gallons in capacity. Still, a powerful submersible heater can be used to create hot pockets in ponds as large as 1000 gallons or more. Insulated pools benefit more from these heaters since they prevent them from seeping away into the cold ground.

But the most common way to heat a smaller pond is to use Deicers.

What Are Pond Heaters & De-Icers?

In most cases, you might not need to spend hundreds (or even thousands) of dollars on heating the entire pond. Many small ponds can be “heated” using a deicer, which is by far the more reasonable (and cost-effective) option. A pond deicer doesn’t heat your entire pond, and neither does it prevent your pond from freezing over in colder temperatures. Instead, it keeps a small area free of ice on the pond’s surface (basically a hole in the ice). This ensures that there isn’t a harmful build-up of gases inside the water of the pond, and enough oxygen diffusion takes place (through the exchange of gases) to keep your fish alive.

A Pond deicer or pond heaters are either floating or submersible. Floating deicers usually keep floating on the surface and maintain an adequate “hole in the ice” for gas exchange between the pond and atmosphere. A submersible pond deicer lies on the bottom of the pond, but they are just as effective in creating and maintaining a small area free of ice on the surface of the pond.

Deicers also maintain warmer water temperatures in their immediate vicinity. It might not be as extensive as a submersible heater is, but it’s still sufficient for many of the pond’s inhabitants during winters and significantly less power-consuming. Pond deicers are preferred for ponds under 300 gallons but can also be used for larger ponds.

What Is The Best Pond Heater?

We have discussed three different heater types:

  1. In-line pond heaters
  2. Submersible electrical heaters
  3. Floating or submersible deicers

Though deciding which one of the three is the best pond heater would depend on your particular pond and the fish it contains, in most cases, a pond deicer is the best option for a pond heater. It’s affordable, simple, and does a good enough job of keeping your pond fish alive, even through harsh winters. But it’s important to understand that a deicer might not be powerful enough for the tropical fish in your pond. But for the wide variety of pond fish, a powerful deicer is enough preparation for the winter.

Here Are The Top 5 Best Pond Heaters

We have prepared a list of five of the best pond heaters/deicers available in the market. Of course, you might find the perfect candidate for your pond on this list. But, even if you don’t, you may glean some insights on how to compare different ponds heaters and what to look for in a good deicer. This will allow you to make an informed choice for your pond and the fish inside, which is essential, as it’s a matter of life or death for them.

1. KH Thermopond Perfect Climate Deluxe Pond De-Icer

K&H Pet Products Thermo-Pond Perfect Climate Deluxe Pond Deicer Black 750W

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A powerful deicer, perfect for small ponds.

  • Dimensions: 7.5″ L x 7.5″ W x 4.5″ H
  • Power: 300 Watts
  • Type: Submersible
  • Materials: Plastic casing

kh pet products thermopond perfect climate submersible pond deicer are designed for small ponds (under 300 gallons, and 18″ or less deep). While it will work in a larger or deeper pond, the result may not be as effective. The depth will mainly be an issue as it’s a submersible deicer and will have a hard time maintaining a hole on the pond’s surface from deeper-recommended-position.

A fantastic feature of kh pet products is that it’s thermostatically controlled, making it even more energy efficient. The shape of the body and color helps it blend with almost any pond’s decor or substrate. It’s powerful enough to keep a small pond adequately heated and ensure the gas exchange even in sub-zero temperatures. In addition, its safety is tested and certified by MET Labs.

The deicer comes with a 15 feet power cord. A larger cord offers the flexibility of placement. In addition, the manufacturers claim that it can be used for larger ponds (up to 1500 gallons) if it’s attached to an external float.


  1. The unit itself and power cord are good quality and heavy-duty.
  2. It keeps electricity costs low.
  3. For a small pond, it can prevent the surface from freezing over. For larger ponds (200 gallons to 300 gallons), it keeps a sizeable pocket open.
  4. The company offers a two-year warranty (Amazon’s guarantee may be different).


  1. Many units are found to have faulty circuits that trip GFIs.
  2. The lack of temperature control on/off indicator on the unit makes it hard to check if it’s functional.
  3. A few units shorted inside the pond, electrocuting the fish.
  4. It only starts heating when water temperatures fall to near freezing, and there is no way to control it.

2. Tetra Pond De-Icer, Thermostatically Controlled Winter Survival Solution For Fish

TetraPond De-Icer, Thermostatically Controlled Winter Survival Solution For Fish, UL Listed

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A stone-shaped deicer to complement the aesthetics of your pond, in addition to keeping your fish alive in winter.

  • Dimensions: 11.3″ L x 6.4″ W x 6.9″ H
  • Power: 300 Watts
  • Type: Floating
  • Materials: Plastic body

TetraPond’s pond deicer can be another friend for your fish during the winter months. It’s shaped like a rock so that it would look beautiful in a beautifully decorated Koi pond. The deicer is powerful enough to keep a small pocket of ice open to release the trapped gases in temperatures as low as -20 degrees Fahrenheit. This floating deicer works even if the surface has already frozen and keeps a tiny area around it thawed. Though it doesn’t act as a pure heater, fish like to clog near it (under it) to stay in the heat pocket it creates to keep the water from freezing.

Like any other deicer, it needs to be installed with caution and properly grounded. Inadequate grounding or the absence of a GFI breaker can result in the electrocution of your fish. However, this particular deicer isn’t known to develop such electrical faults. Also, as a floating deicer, the capacity or depth of the tank is relatively inconsequential. Again, though, it’s recommended that you use this deicer for a pond with a surface area of less than 150 sq. Ft. Multiple heaters should be used for a larger pond.

The deicer is also energy efficient and uses relatively less electricity to keep your fish alive, especially compared to a conventional in-line heater would.


  1. It works well even with thick layers of ice (about 3″) over the pond’s surface.
  2. Not very bulky or unsightly.
  3. Great as a koi pond deicer
  4. Powerful heating element and works well in freezing temperatures.
  5. It comes with a three-year warranty from the manufacturer.
  6. It is reasonably priced.


  1. It doesn’t have an in-built thermostat to shut it off when temperatures start rising above freezing. This usually disturbs the hibernating fish.
  2. If not removed from the pond, this floating pond heater can raise the temperature to 90-degree Fahrenheit, which might not suit cold-water fish.
  3. Large ponds can diffuse the heat their element produces, but it has to be removed or shut off when the pond isn’t frozen for small ponds.
  4. They are known to cause ground fault circuit breakers to trip.

3. Aquascape 39000 Pond Heater and De-icer

Aquascape 39000 Pond Heater and De-icer for Pond Water Feature Gardens, 300 Watt

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Little metallic beast to de-ice your pond.

  • Dimensions: 8″ L x 8″ W x 6.5″ H
  • Power: 300 Watts
  • Type: Floating
  • Materials: Stainless steel

Even though it looks like you dropped a pot in your pond, it does its job of maintaining a hole on the frozen pond surface well. Which, unlike creating a hole in the ozone, is a good thing. A metal body also allows it to disperse heat more effectively. But, on the flip side, it doesn’t blend in with the bond’s aesthetics. One fantastic feature of this floating pond heater is its LED indicator. The LED turns red when the deicer is heating, blue if it’s removed from the water while still powered, and it turns off when you cut the power off. This is very helpful since you don’t need to keep the deicer out of the pond to check whether it’s working or not.

The solid metallic body ensures long life and relatively less water intrusion in the body to damage the heating element. It doesn’t crack or convulse from the temperature changes and doesn’t corrode.


  1. LED indicator helps pond owners keep an eye out without taking it out of the water.
  2. It comes with a three-year warranty.
  3. The thermostat ensures that it turns off before overheating the water (once water around it reaches 70-degree Fahrenheit).
  4. It works perfectly for small ponds with less surface area.


  1. It doesn’t last very long, according to many customers.
  2. Not very useful if the ice on the surface gets thicker than 1 inch.
  3. Typical of most deicers, it trips the ground safety breaker.
  4. It doesn’t clear a large area around it, like other similarly powered deicers do.
  5. It’s expensive.

4. Farm Innovators Model P-418 Premium Cast Aluminum Floating Pond De-Icer, 1,250-Watt

Farm Innovators Model P-418 Premium Cast Aluminum Floating Pond De-Icer, 1,250-Watt

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It’s a powerful deicer for up to 600-gallon ponds.

  • Dimensions: 7.5″ L x 7.5″ W x 4.5″ H
  • Power: 1,250 Watt
  • Type: Floating
  • Materials: Cast aluminum

This little deicer from farm innovators is powerful enough. The 1,250 Wattage may even seem over-powered for many a fish pond, just to keep a hole open in the ice and keep oxygen levels steady. It works best for ponds between the sizes of 50 and 600 pounds. A cast-iron aluminum body means that it’s reasonably corrosion resistant, as well as lighter. In addition, aluminum’s heat dispersion is significantly better and uniform compared to stainless steel is.

It comes in a subdued green body, which might be mistaken for a lily-pad if you are standing too far away. But if you disregard the aesthetics for the sake of the fish living in your pond water, it’s an amazingly powerful product. Since it also comes with a thermostat, it won’t overheat and discomfort the fish when the temperatures warm up a bit. In addition, it comes with a ten-foot cord, which many may not find long enough, especially considering it’s intended for relatively larger ponds.


  1. It creates a decent-sized hole in the ice, usually two feet across.
  2. It works perfectly for small and large-sized ponds alike. Many people even found it useful for 1,000-gallon ponds.
  3. The thermostat helps keep the electricity bill relatively low, especially considering the 1,250-watt heating element.
  4. Works for almost all pond types.


  1. Many people found it inadequately sealed. This allowed water into the unit.
  2. It doesn’t seem to last long for many customers.
  3. The quality of the constructions seems poor.
  4. Not as energy-efficient as 300-watt deicers.

5. API Floating De-Icer / Heater – 1500 Watts

API Floating Water Tank Deicer Floating De-Icer with Guard, 1500 Watt (Item No. 521G)

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It’s a reasonably priced, powerful heater for ponds and tanks alike.

  • Dimensions: 14.6″ L x 15″ W x 5.4″ H
  • Power: 1500 Watts
  • Type: Floating
  • Materials: Plastic housing and steel element

Miller Manufacturing Company manufactures the API Floating deicer. They are experts in farm-related equipment. The floating deicer act both as a tank, pool, or pond deicer. The recommended pond size for this deicer is 100-300 gallons. It also comes with a metal guard, which prevents the heating element from coming into contact with fish in the pond or the walls of a tank.

If you keep it in a tank below 300 gallons, the manufacturers claim it will provide enough heat to keep it completely ice-free. Unfortunately, the same might not be applicable for a large pond because of its poor heat insulation. It comes with a 15-feet cord and a thermostat for efficient energy consumption.


  1. Its power acts more like a heater than a simple deicer, but only in recommended pond sizes.
  2. This deicer has a long life.
  3. It is reasonably priced.
  4. Construction is sturdy.


  1. Prone to shorting.
  2. Usable only for smaller ponds, despite a powerful heating element.
  3. Unsightly and bulky, especially with the metal guard.
  4. Better suited for tanks than for ponds.

6. Oase Pond Heaters

The fish pond heater from Oase is great.

Features To Consider

Some essential features to consider in a deicer/ pond heater to maintain are:


The first thing you will need to choose is whether to use a floating deicer or a submersible one. Floating deicers are better at creating and maintaining a hole on the surface of a frozen pond. But they are also a bit obtrusive and offset the aesthetics of a pool.

Submersible deicers are unobtrusive. They are out of sight and may work well as pond heaters, up to a certain extent. But they aren’t as efficient in maintaining a pocket of water in the icy surface of the pond, especially if the pond is too deep.

In terms of functionality and effectiveness, floating deicers might be better.


Understanding the capacity, and in some cases, the surface area of your pond and buying an adequate deicer is essential. Some deicers are rated based on the gallon capacity of the pond. At the same time, others may only be used for ponds that have a specific surface area.

The capacity is vital if you are using an in-line or a submersible heater instead of a deicer. The wattage of your heater should be directly proportional to the capacity of your pond. But that’s only necessary if you have temperature-sensitive fish (tropical fish) in your tank. Otherwise, a deicer works just fine to ensure proper gas exchange in frozen ponds and raising the water temperature nearby high enough for fish to feel comfortable.


The deicer needs to have adequate wattage to maintain a hole in the ice, facilitate the exchange of gases, and provide a little hot pocket of water in its immediate vicinity. But it’s also linked to the cost of running a deicer 24/7 during the winter. So the higher the wattage, the higher your electricity bill may be.

The wattage calculation of a pond deicer is different from a pond heater’s calculation. Since the primary job of a deicer isn’t to heat the water, an excellent low-powered (300 watts) deicer is usually enough to create and maintain a hole in the icy surface of larger ponds (500 gallons to 1000 gallons) during winter.

But for an electric submersible heater or an in-line heater, the wattage should be directly proportional to the tank’s capacity and the temperature you need to maintain. So while one watt per gallon is enough to raise the temperature of a pond ten degrees higher (for about a 1000 gallon pond), the same won’t be enough if you want to keep your pond at 70 degrees Fahrenheit during ice-cold winter. And a powerful heater would consume significant amounts of energy to maintain high temperatures.


Excellent materials and durable construction ensure that your deicer can survive sub-zero water temperature and won’t rust despite being consistently in water. Many people only use their deicers in winter and keep them on the shelf for the rest of the years. It’s a good idea to clean them up before storing them. A strong, sturdy wire is also an important part of durable construction.

Safety and Efficiency

The efficiency of a deicer is dependent mainly on the presence, quality, and parameters of the thermostat. A pond deicer that doesn’t have a thermostat might end up increasing the temperature too much when the ice is gone. This increase can sicken, and in some cases, kills the fish that have prepared their metabolism for hibernation. On the other hand, a thermostat ensures that the heating element is fired up when needed and closes off when the water is warm enough. This saves your fish and your electricity. Pond deicers usually come with preset thermostat parameters, so if your fish have unique temperature requirements, you should read through them as well.

The safety of a pond deicer mainly pertains to its grounding. If a pond deicer is not adequately grounded and develops an electrical short, it can electrocute the fish and shock you. Some deicers aren’t suitable to be used with pond liners.

Do I Need A Pond Heater or Deicer:

Yes. You do need a deicer if you have fishes or frogs in your pond, and the pond tends to freeze solid over in the winter months. And no, you don’t need a pond heater unless you have tropical fish with specific temperature requirements. Even then, it might be less costly to set up an indoor tank and remove your tropical friends to that and wait for the winter to pass to reintroduce them to the pond.

A pond cover can also be used to help keep the elements out and the heat in. Lastly, an aeration kit can help keep the water moving to prevent freezing and push the warm water around the pond.

Why Are Pond De-Icers & Heaters Important?

Deicers are crucial because even if some fishes can survive at very low water temperatures, they can’t survive trapped with dangerous gases. That’s what happens when a pond completely freezes in winter. Decaying food and waste releases gases that contaminate the water. Usually, these gases escape the water and into the atmosphere through the surface of the pond. But if it’s frozen, these gases can’t escape, and they can sicken and kill your fish. Also, oxygen can’t enter the water through a layer of ice. So there needs to be a way for this imperative exchange of gases to happen: Oxygen coming in, dangerous gases going out. A deicer facilitates that. It creates one decent-sized hole in the ice to let poisonous gases escape and oxygen to be absorbed.

Related: We review some of the best pond aerators and explain why they are essential pieces of equipment for your pond.

What Size Is Right: How Many Watts Do I Need For My Pond?

That depends if you are using a deicer or a heater. For a heater capacity of the pond and the temperature requirement of your fish are both essential.

For deicer, your pond size to wattage guide is as follows:

  • Up to 250 gallons: 100 – 250 watts
  • Between 250 and 500 gallons: 300 watts
  • Between 500 and 1,000 gallons: 750 watts
  • Between 1,000 to 1,500 gallons: 1,250 watts
  • Between 1,500 and 2,000 gallons: 1,500 watts

But it’s better to follow the size guidelines of the particular deicer you are using. Some low-powered ones may work for larger ponds as well.

How Do Deicers Work?

Deicers have a heating element that keeps the water warm around its immediate surroundings. It thaws the ice around itself and maintains a pocket of air on the surface of the pond.

How To Install A Pond Heater

Most deicers are very easy to install. If they are floating, you just have to place them on the surface of the pond, plug them in, and they start working. If the pond is already frozen, it’s better to create a hole first, ideally by thawing the ice over the pond water with hot water. Similarly, you can place the submersible deicers in the pond. Make sure you follow the instructions of the manufacturers. You must run your pond heaters through outlets that are connected to the GFI breaker. Some deicers may work in conjunction with pumps or bubblers.

Can I Heat My Pond Cheaply: What Does It Cost To Run A Pond Heater All Winter?

A 1,000 Watt in-line heater for a 1,000-gallon tank may only keep the temperatures ten degrees above the atmospheric temperatures. So it can add about $100 to your electricity bill. If you need an even higher temperature increase, say you need to maintain your pond at 50-degree Fahrenheit while it’s about ten degrees outside. So your in-line heater can cost you up to $500 a month just in electricity.

A deicer uses significantly less energy, especially if it has a thermostat built-in. But there are even cheaper ways to heat your pond. One method is to remove and replace some of your pond water with hot water from the supply line. You can replace the water using buckets or a pump and feed the pond hot water from a tap or another source. It will raise the temperature of the pond up to a certain extent, but only temporarily.

If you just need to thaw some ice from the frozen surface, you can pour hot water from a bucket or another source. But it will freeze over eventually, and you may have to repeat the process to let your fish breathe.

Related: Should I Leave My Pond Pump Running in the Winter? What You Need To Know!

Final Thoughts

We are a bit torn between TetraPond De-Icer and Aquascape 39000 Pond Heater and De-icer for our top pick. While most of its users prefer and beloved the former, the faulty thermostat is a bit problematic. Though as far as its heating capabilities are concerned, it’s fantastic.

The Aquascape Pond 39000 lacks a bit in heating power. But it more than makes up for it with its LED indication feature. But even if they aren’t the best pond deicers available in the market, they might be two of the best pond deicers out there.

So if you are preparing your pond for winter and want to see the inhabitants of your pond water happy and alive after winter, you may need to make the right choice regarding the pond-heater/deicer.

Remember, a water garden pond is not only an investment but a considerable commitment. The pond maintenance alone can take up an entire weekend if you don’t have the right equipment like an external pump, pressurized filters, pond vacuum, algae control, test kits, and pond filters

Lastly, after all the maintenance is done, you want your pond to look the best it can, so you’ll need to invest in water features, pond lighting, pond plants, or maybe a pondless waterfall.

Learn More About Keeping An Outdoor Ponds In Your Backyard:

Pond Heaters & De-Icers For Small Ponds


Jack Dempsey