8 Steps On How To Heat Your Pond In Winter

Colorful fish and aquatic flowering plants in a pond.

Heating your pond in the winter and providing a natural environment will help your fish throughout the entire season. The warm temperature ensures aquatic inhabitants have the best chance of survival until the cold climate passes.

In winter months, the water temperature drops to about 45 to 50 degrees Fahrenheit which is about 7 to 9 degrees Celsius. (Varies on where you are located)

Yet many small pond owners keep koi without heating their water. This is because fish like koi and goldfish are hardy. These naturally cold-blooded species can handle cooler temperatures.

But their metabolism and activity slows, and showing no interest in anything in winter means they are suffering from stress because of undesirable cold temperatures.


 8 Tips On How To Keep Your Pond Warm In Winter

When it comes to heating small ponds in winter, there are some factors you need to consider. You can use traditional techniques like keeping the pond free from the organic matter before the winter comes or use innovative heating equipment for ponds.

However, some pond owners can get confused about what might be necessary for their ponds.

Do koi and goldfish need different water temperatures to live in? Do these fish need a specific temperature to survive in winter? What fish pond heater should I use to keep my pond heated in winter?

Below, we’ll talk about some fish pond heating solutions and how they provide a constant temperature during the freezing winter.

1) Provide Pond Covering

Winter pond cover made of PVC and clear plastic cellophane in the greenhouse style.
Image by: pondexperts.ca

Providing your pond with a cover is an excellent way to maintain the surrounding air of your pond during the winter.

The winter pond cover acts like a greenhouse. It helps warm the water during the day and traps the heat inside at night. Besides, it eliminates chilly wind from sweeping across the pond, pulling the heat out from any open water.

Using a floating plastic cover on the pond’s entire surface is also another option to consider, particularly if you have no water heater available or when power fails.

2) Use Heating Equipment

An icy pond with a waterfall and hole in it surrounded by orange flowersImage by: fishtankadvisor.com       

A pond heating system can provide a convenient way to keep your pond warm in the colder months.

Some heating solutions will heat the water through a heat exchanger. And then the pond’s water will flow from the tank setup past the pipe which means the heat goes down to the pond’s cold water.

You’ll find different heating systems with capacities suitable for raising the pond’s heating potential – have it be of several gallon pond volumes above the surrounding temperature.

However, the downside is you need to consider the installation and the running pond cost besides the purchase price. 

  • Generate Hole with De-icers 

In winter, keeping a small hole in the ice surface is essential to allow gas exchange and prevent a buildup of toxic gases.

And a pond de-icer is the lowest costing heating solution you can have to heat your pond. But because it floats on the surface in an exact spot, it generates an uneven temperature across the pond.

However, if your primary goal is to generate a hole for gas exchange to take place, a de-icer electric heater is the best equipment for such a purpose.   

Using a de-icer will make the job easier. The electric heater in disk shape is excellent in creating a hole in the ice surface.

Other types of floating heaters feature an automatic switch and function well on the water surface. This hole generator electric heater offers convenience as it switches on automatically once the water freezes.

  • Warm Water with Inline Heaters or Boilers

Other pond heaters you can use to heat the pond during winter are an inline electric water heater or gas-powered boiler.

The inline electric water heater and the gas-powered boiler are excellent in passing the hot water from the heating chambers down to the whole pond.

Both pond systems pass warm water back into the pond to prevent it from freezing. But the boiler system costs more with poor selection than a de-icer.

But when the water flow is already colder than the desired temperature before the installation of the device, you’ll want to warm the water gradually about one degree each day to avoid the risk of shocking the fish and other aquatic inhabitants.

  • Add Aeration with Air Compressor
Adding a pond submersible air compressor is another simple way to improve the oxygen content in a pond and help increase water movement. As the water plunges purposefully over rocky streams and waterfalls, it generates natural contact with air.

Submersible pumps help maintain the water hole in winter ponds that are open to releasing toxic gases and ammonia. When these toxic gases are not released, it could mean harm to your fish. Besides, it adds a level of oxygen to the pond during the winter.

Fish do not need the same level of oxygen as they during the summer, but an aerator can be very beneficial when large koi about 12 inches or numerous goldfish are in the pond in cold winter months.

3) Consider Efficiency When Selecting A Pond Heater

Coldwater can hold dissolved oxygen more than warm water, but too cold of water can slow the metabolisms of most fish resulting in lethargic bodily functions.

Also, when water suddenly turns too cold in winter, it can cause shock to the fish. Such an occurrence will cause mass fish deaths, particularly in regions with harsh climates.

The primary reason for heating a pond is to reduce the stress for your koi. Therefore, considering the efficiency of a pond heater that provides optimal water and heating is essential. Because using unreliable heating elements may cause your fish more harm.

When an installed pond system stops heating in the frozen pond, and the water temperature drops, it can be too stressful for your fish. A sudden 20-degree drop of temperature over a few days is fatal to your fish.

4) Clean the Pond Before the Winter Begins

Pond with crystal clear water surrounded with stone and ornamental plants.
Image by: swelluk.com

Before the winter begins, clean the bottom of the pond floor and remove any organic debris.

Organic debris such as dried leaves, fish waste, and dead vegetation present in the pond will probably use up dissolved oxygen as they decompose in the winter. And this will without a doubt cause harm to your fish.

Also, a water change of at least 50% of the water pond is necessary. The sediment stirs up upon cleaning the pond floor, and the turbid water will probably suffocate the pond’s plants, irritate fish gills, and smother fish eggs.

Some use water treatment and purification, using beneficial bacteria to keep the pond clean until the warm weather returns. However, the build-up of organic waste feeds pond algae causing green water come spring.

5) Feed Fish Sparingly

Handfeeding the goldfish in the pond.
Image by: thepondguy.com

When pond temperatures drop in winter months, feeding fish with excessive amounts will do more harm than good. During the winter, the metabolism of the fish will naturally slow which causes them not to eat as much.

Besides, food excess can diminish water quality and dissolved oxygen when it breaks down. It will dissipate as ammonia, which is toxic to the fish.

When the winter temperatures fall below 50 degrees Fahrenheit, it is better not to feed your fish until the minimum temperature returns. This way, they will make ends meet with algae, insects, or any pond plants.

6) Move Fish Indoors

Carp with a combination of white and orange colors in a blue plastic barrel.
Image by: quickcrop.co.uk

Moving fish that don’t do well with overwintering from outdoor ponds to an indoor pond or aquarium with temperature control is essential to help them survive.

Fish varieties such as pleco, oranda, and black moor need to be brought inside, particularly in colder climates. Doing so will lessen the risk of damaging their health. Obviously, this is a hard task depending on your given circumstances but if possible then it is beneficial to specific species of fish.

7) Ensure An Appropriate Pond Depth

Deep koi pond with egg-shaped stone edging.
Image by: angieslist.com

Pond depths vary, particularly outdoors, and shallow ponds can affect the health of your fish in winter months. Koi and goldfish are hardy and can withstand overwintering, but only if the pond water has over a 4-foot depth.

The deepest point, such as the pond floor, allows stratification to occur, preventing the entire pond from freezing. Yes, ponds with sufficient depth do not freeze completely.

Besides, it provides a refuge where fish can hang out to escape from the cold conditions as they enter a torpor state to conserve more energy. Moreover, protect themselves from predators while in a state of dormancy.

If you live in regions with freezing winters, make sure your pond is at least 4-feet deep to ensure fish have a warmer section to habitat in.

8) Keep Ice and Snow at the Top Surface of the Pond

Icy pond surface.
Image by: fullserviceaquatics.com

Leaving the ice and snow at the entire top surface of the pond may be contrary to what you think in helping your fish overwinter.

It actually acts as an insulating layer protecting your pond from harsh winds and constant fluctuations of a winter temperature.

You’ll need to maintain a hole for gas exchange, but if you live in a northern region with colder temperatures, you’ll want to keep the ice at the top surface to help protect your fish.

In warmer areas like Florida, you may not concern yourself with a pond pump when overwintering as long as the water temperature remains above 50 degrees Fahrenheit.


Final Thoughts On Heating Your Pond

The water quality and temperature in freezing months can influence the overall health of your fish in the pond, making it essential to prepare the pond – be it large or small before the temperatures drop in winter.

Of course, fish have different level of requirements for water temperature, oxygen, and pH range. Therefore, it is essential to have fish that will do their best in a healthy environment they can sustain.

Goldfish prefer temperatures around 50-55 degrees Fahrenheit, and like Koi, they enter a torpor state to reserve more energy which helps them survive the cold winters.

If you love and enjoy the enthusiasm of your fish, heating your pond is the right move for you. It doubles the time you’ll spend with your lovely fish with fewer worries by having control over your entire pond all season long.

And also, keeping your pond heated in the winter can also take a lot of stress off of you. You won’t have to worry about your fish dying on you and you can also feed them during the winter without having to worry about any issues that might occur come summer. 

If you have any questions, don’t hesitate to ask below!

About Benita Abucejo

Hi there! My name is Benita Abucejo. What can I say? I truly love spending my days in the outdoors, specifically in the garden. Gardening has always been a strong passion of mine since I was a little girl. It has brought me so much joy and happiness that it is definitely safe to say that I will be a gardener for life. For a period of time, I was able to work with people who are into home gardening and I found it to be quite beneficial to my physical health, as well as my mental well-being. Here at Seasonal Preferences, I am going to share with you my experience and ideas so that you can fulfill yourself with the same satisfaction and happiness. Of course, if you have ideas, I would love to hear those as well! Being creative in the garden can really be quite fascinating so let's share our experiences and be the best gardeners we can be. With that being said, thank you for dropping by and please leave me a comment on one of my posts if you would like to get in touch!

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