Goldfish Water Temperature: Ideal Set-Up For Your Tank And Pond

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Goldfish are some of the most common and well-known fish kept as pets. They are famous for their wide variety of colors and sizes, and they are relatively easy to care for. One important aspect of goldfish care is maintaining the proper water temperature.

This article will discuss the ideal water temperature for goldfish, how to set up your tank or pond to maintain that temperature, and what to do if the temperature gets too high or low.

Goldfish Are Cold Water Fish

Before delving into the ideal water temperature for goldfish, it is important to note that goldfish are cold-water fish. Biologically speaking, goldfish are more tolerant of cooler water temperatures than tropical fish. In fact, goldfish can withstand temperatures as low as 50˚F before they start hibernating or experiencing health problems.

However, this does not mean that you should keep these hardy fish in water that is too cold. Goldfish that are kept in outdoor ponds may experience a wide range of temperatures depending on the season, but it’s important to ensure that the pond does not freeze over in the winter months.

On the other hand, goldfish living in warm climates need to be adequately protected from the heat. Things like building a shade for your pond, or using a pond chiller can help keep the water temperature down in the summer months.

What Is The Optimal Temperature For Goldfish?

So, what is the ideal water temperature for goldfish? The answer may surprise you, but goldfish do best in water on the cooler side. In general, the ideal water temperature for goldfish lies between 65 and 72 degrees F or between 18 to 22 degrees centigrade.

This optimal range is important for several reasons:

  1. Goldfish are less active in cooler water, so they don’t need to consume as much oxygen.
  2. Cooler water is also less likely to support the growth of harmful bacteria and parasites.
  3. Cooler water helps prevent goldfish from becoming over-heated, which can lead to health problems. 

Factors Affecting A Goldfish’s Ideal Water Temperature

Although the ideal water temperature for goldfish is fairly consistent, a few factors can affect what is best for your fish. Let’s take a look at a few of these factors.

Type Of Goldfish

One factor that can affect the ideal water temperature for your goldfish is the type of goldfish you have. As we mentioned before, goldfish come in various colors and sizes, but they generally fall under fancy and slim-bodied goldfish varieties.

Slim-bodied goldfish include species such as the common goldfish and comet goldfish. They can tolerate warmer water and cool temperatures better than fancy goldfish, though this doesn’t mean you should go ahead and submerge them in hot water. If you have a goldfish of the slim-bodied variety, you will likely find that they do best in water on the cooler side, between 55 and 75 degrees F.

On the other hand, Fancy goldfish are not as tolerant of temperature changes. This type of goldfish includes breeds such as the oranda and the bubble eye. If you have a fancy goldfish, you want to keep things as close to goldfish water’s ideal temperature possible. This means maintaining a water temperature between 68 and 72 degrees F.

Regardless of what temperature you choose, it is important to make sure that the temperature is consistent, and that you maintain a constant temperature as much as possible. Sudden changes in water temperature can stress out your fish and lead to health problems.


Couple goldfish

Did you know that the ideal water temperature for goldfish can also change depending on whether or not they are breeding? If you are trying to breed goldfish, you will want to slightly raise the tank water temperature. Consider warmer temperatures typically found in the springtime between 68-74 degrees Fahrenheit, but make sure that you don’t go any higher than this.

The reason for this is that warmer water speeds up the metabolism of goldfish, and this can cause them to produce more eggs. If you are looking to breed goldfish, then you want as many eggs as possible, so raising the water temperature can be helpful. Of course, you still want to make sure that the aquarium water temperature doesn’t get too high, as this can be harmful to your fish.

In many cases, hobbyists use an aquarium heater to raise the temperature of their goldfish tank during breeding season. This is a good idea, as it allows you to maintain a consistent water temperature, which is important for your fish’s health and the success of your breeding efforts. 


bright sun in the sky and orange umbrella

While we cannot control the climate, it is important to consider when setting up your goldfish tank or pond. The goal here is to maintain fish health year-round, and in some cases, this means making adjustments to the water temperature based on the season.

For example, in areas with warm summers, you may need to use an aquarium chiller to cool down the water in your goldfish tank. On the other hand, if you live in a cooler environment, you will need to invest in a water heater for the cold winters. Goldfish don’t necessarily prefer warm water, but it is necessary to prevent them from going into shock due to the sudden temperature change.

In short, the ideal water temperature for goldfish will vary depending on the type of fish you have, whether or not you are breeding, and the climate you live in. As a general rule of thumb, you want to keep the water temperature between 68 and 72 degrees Fahrenheit, though some fish tolerate wider ranges. 

What Happens If You Don’t Maintain A Comfortable Temperature?

If the water in your goldfish tank or pond is too cold, your fish can become sluggish and stop eating. You risk exposing your goldfish to diseases and parasites, as cold water makes them more susceptible. In extreme cases, goldfish may even die from exposure to cold water.

Temperature in front of an aquarium

Common goldfish diseases include Ichthyophthirius multifiliis (ich), white spot disease, goldfish fungus, and swim bladder disease. These diseases can be deadly, so you must provide your fish with the correct environment to live a healthy life. The average life expectancy of a goldfish is 10-15 years, but with the proper care, they can live much longer.

On the other hand, if the water in your goldfish tank or pond is too warm, your fish can also become sick. High water temperatures are one of the leading causes of death in goldfish. High water temperatures can cause your fish to overheat, leading to organ damage, problems with the nervous system, and even death.

As you can see, it is vitally important that you maintain a comfortable water temperature for your goldfish. The good news is that this is relatively easy to do, and as long as you have a quality aquarium heater and/or chiller, you should be able to keep your goldfish happy and healthy.

Final Tip: Invest In A Good Water Thermometer!

We’ve established that the water temperature is important for goldfish health, but how do you know your tank or pond’s temperature? The answer is simple – invest in a good water thermometer!

There are many different types of water thermometers on the market, and you can choose one that best suits your needs. For example, if you have a large goldfish tank, you may want to invest in a floating thermometer. These devices are placed in the water and float on the surface, making it easy to get accurate readings.

On the other hand, if you have a small goldfish tank or pond, you may want to invest in an aquarium stick-on thermometer. These devices can be found in your neighborhood pet shop, and they are very easy to use. All you have to do is stick them on the inside of your tank or pond, and they will give you an accurate reading of the water temperature.

No matter what type of thermometer you choose, it is important to check the water temperature regularly. Maintaining the right tank temperature for goldfish is a crucial aspect of keeping your fish healthy, and you want to make sure that you are providing them with the best possible environment.

The Takeaway

To summarize, the ideal water temperature for goldfish will vary depending on the type of fish you have, whether or not you are breeding, and your climate. As a general rule of thumb, you want to keep the water temperature between 68 and 72 degrees Fahrenheit, though some fish tolerate wider ranges.

We hope you found this article helpful. If you have any questions or comments, please feel free to leave them below. And if you want to learn more about goldfish care, be sure to check out our other articles! Thanks for reading, and good luck with your goldfish!

Wanda is a second-generation aquarist from the sunny tropics of Malaysia. She has been helping her father with his freshwater tanks since she was a toddler, and has fallen in love with the hobby ever since. A perpetual nomad, Wanda does her best to integrate fish-keeping with her lifestyle, and has taken care of fish in three different continents. She loves how it provides a nice break from the hustle and bustle of life.

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