The winter season can be harsh for fish. Water temperature falls below freezing point and the cold winter months and the lack of food make it difficult for them to survive. So, in order to ensure that your fish can enjoy a safe and healthy winter season you should winterize your pond.

You will need to create an ice-free area in your pond, so that the crucial gas exchange is still possible. And you will need to know how deep your pond is and what its surface area is.

Then, you will need to identify which plants and wildlife need protection from the cold weather during this time of year.

So, how do fish survive winter in ponds? Read on to learn the different steps you have to take to ensure the well-being of your friendly pond inhabitants.

Location of the Pond

The first step to winterizing a fish pond is to look at the location of your pond. Obviously that has to be done before even building the pond. The pond should be situated in a spot where it will not freeze over for more than 10 days. If this is not possible then relocating the fishpond near or under sheltering trees should be considered.

You also need to watch the pond depth. There should a space where it is at least 45 in (120 centimeters) deep. The deeper water will ensure that the pond doesn’t freeze solid and your fish have an area of unfrozen water where they can survive.

Another precaution is adding a thick layer of insulation to the bottom of the pond. This will prevent water from freezing from below and allow it to stay liquid.

Prepare your Pond for the Winter

The second step is to clean your pond. Before the first frost, be sure to remove leaves and other organic debris in order to make sure they do not decompose in the water. Garden pond owners should use a mud vacuum to remove parts of the bottom mud. Doing this prevents toxic gases from being released and impurities to accumulate. This will help to keep your pond fish healthy.

How do Fish survive Winter in Ponds? By being well-fed!

Pond fish are cold blooded and need extra energy reserves for the colder months. Therefore, as the third step they should be given special winter food from early October on. As soon as the water temperatures drop below 50 degrees F (10 degrees C), their metabolic rate slows down and the fish stop feeding. In the spring, with warmer water temperatures above 50 degrees F (10 degrees C), you can begin feeding your fish again.

How do fish survive winter in ponds? By being well-fed!
How do fish survive winter in ponds? By being well-fed! – Image by Peter Timmerhues from Pixabay

Remove sensitive Fish during the Winter

As the fourth step you have to decide which fish to keep in the pond and which ones to relocate. When you live in an area with cold winters, native fish species are a good choice. For most native fish, staying in cold water during the winter is not a problem. The only important thing is that the fish get enough oxygen.

But even some exotic species are capable to adopt to different conditions. Goldfish, for example, will survive well during wintertime in the garden pond due to their ability to tolerate low temperatures.

However, more sensitive species have to be brought indoors. They require an aquarium where they can be provided with proper housing for the winter. If the animals come indoors, the location of the aquarium should be frost-proof, but not too warm. The temperature should not drop below 50 degrees F (10 degrees C). In addition, the aquarium should be spacious enough. The length of the aquarium should be at least six times the size of the largest fish.

Ensure sufficient Oxygen in the Pond

To ensure that the pond inhabitants get enough oxygen, there shouldn’t be too much water in the pond. If necessary, you have to drain some water from your fishpond when the ice forms. Don’t drain too much water though, as there should be a spot at least 45 in (120 centimeters) deep. The spot should ideally be somewhere where the fish can still move around a bit.

Additionally, the pond should not completely freeze over and must always have at least one section of ice-free water – this is essential to ensure that the animals survive. When it comes to keeping ice-covered ponds afloat, there are ice-free holders with and without aeration. This not only prevents the pond from freezing, but it also helps carbon dioxide escape.

Do not chop up the ice cover!

If an ice cover has already formed, you should not chop it up so that the fish are not disturbed in their winter rest. The easiest way to make a hole in the ice is to use warm water. However, do not walk around on the ice while doing this! Not only do the steps on the ice surface cause severe stress for the fish and endanger the health of the animals, you could also break in.

Check Water Quality also in Winter

You also have to check the water quality. In the still water, it’s easier to see how much algae and other debris is floating in the pond water. It’s important to remove this, as it can build up and clog filters and provide a breeding ground for bacteria, parasites, and disease.

Conclusion – How do Fish survive Winter in Ponds

As you can see there are only a few simple steps to make sure your pond fish survive the colder temperatures in winter. When you adhere to this advice, you will be rewarded in spring with healthy fish and the good feeling you helped your little fellows overwinter.