Ideal Water Temperature for Goldfish in Winter & Summer

Goldfish Tank

Goldfish are the most popular pet fish and be found at various pet stores around the country. Goldfish are one of the longest living fishes in the world with the oldest living goldfish reaching the age of 49 years.

On the average, goldfish kept in small bowls live up to 5 years, while those living indoors in aquariums can live up to 10 years. Goldfish in ponds can live up to 20 years, sometimes up to 30-40 years.

The maintenance of their habitat is very important as it plays a role in their life. In the wild, goldfish naturally prefer the slow-moving, calm freshwater. Goldfishes also prefer cooler waters and therefore should not be kept in tropical aquariums.

Let’s have a look at the water temperature that is suitable for Goldfishes. You really do not want to learn by the “Trial and error method”. Information is power and in this article, you will get the right information that you seek.

When you start keeping goldfish, there are some factors that you consider which include; water availability, area, location, soil, breed of the fish etc. But the most important of all is water.

Water Temperature for Goldfish

The temperature of your water can have a great effect on your fishes; the wrong water can make your goldfishes unhealthy making them susceptible to diseases. What water temperature is just perfect for Goldfishes?

The best water temperature for goldfish is between 23-24 degrees centigrade which is (73-75°F). Although goldfish can live in temperatures as high as 30 degrees centigrade, it is recommended that they are kept in within this range. Goldfish can become stressed in higher temperatures.

Do goldfish like warm water?

Goldfish are cold-water fishes and to some extent can withstand a wide range of different temperatures, both indoor (aquarium) and in outdoor ponds. However, this does not mean that close attention should not be paid to their environment.

If the tank water is too cool, the goldfish will swim more slowly than normal and will definitely show less interest in any activity including feeding. It reduces their level of performance in the water.

Also, if the tank water is too warm, it exposes your goldfish to diseases and other illnesses; an example is Swim Bladder disease. Goldfish are happy when they live in a normal temperature range.

Goldfish Water Temperature in Winter

The winter is the coldest season of the year. Goldfish can survive in an outdoor pond as long as the pond depth is deep enough so that the water would not freeze all the way from the top to the bottom.

If this happens, the goldfish will freeze along with the ice which you don’t want to happen. In a pond that is at least 4 feet deep, the fish will hibernate temporarily to make it through the winter.

Goldfishes are very hardy fishes; they can survive harsh water temperature to some extent, which means they can survive in the pond during winter as long as it is not solid freeze. They need adequate water and oxygen.

For the goldfish to survive during winter, the feed is important too. Once the water temperature falls below 15°C, you should start feeding them a cold water food. As the water temperature goes down, you should reduce the quantity of feed that you give them.

As soon as the temperature reaches 9°C, it is recommended for you to stop feeding them because their metabolism slows down at this stage that their digestive system does not process food.

Feeding them at this temperature will result in food lodging in their guts causing serious problems to their health. To be certain of the water temperature, you can make use of a pond thermometer. During the winter, you should aim to keep the water temperature within the range 60-75 Fahrenheit (16-24°C).

As winter approaches, you should remove trees and other plant materials from the pond. These materials if left in the pond will decompose in the winter months causing an elevation in the ammonia and nitrite level and low oxygen level in the pond. The only way to prevent this is by making use of pond nettings.

Adding cold water beneficial bacteria during winter have also proven to be effective. Cold water beneficial bacteria such as Microbe-Lift Autumn Prep contain enzymes that can break down any residual leaves or organic matter in the pond and can help to sustain the biological activities in the cold water.

Maintaining good water quality alongside the water temperature during winter is the key to keeping your goldfish alive and healthy until spring.

During winter, the water as the top of the pond tends to freeze, maintaining a hole in the ice is important for the goldfish’s survival. You can make an opening in the ice to allow oxygen to get inside the pond and to release unwanted gases out of the pond. A pond heater or aerator can be used for this purpose.

Goldfish

Goldfish water Temperature in summer

Goldfish perform very well in aquariums as long as you keep track of the tank water temperature during the summer. It is recommended for you also to change the cold-water frequently.

The water temperature should not go beyond 90°F. Maintaining the temperature down around 70°F is perfect for the goldfish’s health year-round.

In summer months, the cooler water will stay at the bottom of the pond (hypolimnion) with warmer water at the bottom (epilimnion).

The hypolimnion contains more dissolved oxygen than the epilimnion, and so during summer, do not be surprised when your goldfish spends more time at the bottom of the pond where oxygen is readily available.

This will not only affect your goldfish but any other organisms present, from plants to bacteria. This is simply because they would not be able to survive. Extremely high temperatures (over 30°c/86°F) can harm your goldfish.

Here are some tips to cool your Aquarium water:

  1. Turn off the aquarium water off
  2. Try to avoid direct sunlight
  3. Remove the lid from the tank
  4. Position a fan near the aquarium
  5. Float ice packs in the water to cool it.

Whatever method you use, always note that rapid water temperature change is harmful to your fish. In the summer, just try your best to keep your aquarium cool.

What temperature is too cold for goldfish?

Goldfish are cold water fish that live in cool lakes, streams, and river. However, this does not mean that they should be kept in cold water. When the water temperature is too cold, the goldfish will stop eating and might even hibernate or die.

When the water temperature falls below 50-55°F, it is classified as been too cold for the goldfish. Once this happens, the goldfish will prepare to go into hibernation. However, with the help of a pond heater and thermometer, you can effectively manage and regulate the water temperature.

How to achieve the desired water temperature and how to check it?

Water temperature plays an important role in the health of the ecosystem; therefore managing the water to get the desired temperature is an important aspect of pond keeping.

The seasons (winter and summer) have the highest impact on water temperature, with pond water freezing in winter and warming in the summer.

To keep track of the temperature, you can install a water thermometer. To get accurate readings, it can be done in two ways; one is using a floating water thermometer to measure the temperature at the surface and using a submersible thermometer to measure temperatures at deeper areas. To foster great accuracy, check the water temperature both in the morning, midday and at night, then calculate the average.

Water temperature for Goldfish

In the summer months, a water quality test kit can be used to keep the PH level in check.

Thermometers for Goldfish Tank

Let’s have a look at some of the thermometers that we recommend for monitoring water temperature. They are all available on Amazon.

1. Laguna Pond Celsius and Fahrenheit Scale thermometer.

The Laguna thermometer is a floating device which takes readings at the surface alone. This particular thermometer can take readings in both Celsius and Fahrenheit. It is quite easy to use.

The readings can be viewed through the transparent window with the help of an indicator. The Laguna floating thermometer takes temperature readings between 30 to 120 degree Fahrenheit and it is light; the materials are made of plastic which makes it light and fish friendly and at the same time non-corrosive.

2. Adealink Mini Digital Thermometer

This is a digital type which allows for deeper temperature readings in comparison to a floating thermometer. When measuring, for accuracy, it is advisable to take measurements at different positions in the pond. You also need to hold the probe in place until the thermometer gets a stable reading.

3. Dual Laser Digital Infrared Thermometer

This thermometer provides temperature readings without needing to come in direct contact with the water. All you need to do is to simply point the thermometer at the desired surface, press the measurement trigger, and instantly receive the temperature readings. The equipment also has a convenient unit conversion operation which allows you to convert between Celsius and Fahrenheit units with ease.

Heater for Goldfish Tank

Lets us also have a look at these aquarium heaters that you can make use of to maintain the water temperature for your goldfish. They are also available on Amazon.

1. Titanium Aquarium Heater

This metal aquarium heater tube is made of titanium, which is light weighted, durable and corrosion resistance. It is suitable for use in small and medium size tanks. The heater stops heating when the water temperature reaches the “set temperature” and restart heating when the water temperature is 1°F less than the “set temp”. All you need to do is to set your desired temperature and leave it to work.

2. Uniclife Submersible Aquarium Heater

This heater must be fully immersed and should be placed diagonally vertically in the aquarium, rather than horizontally. The installation is quite easy; you just need to attach the suckers to the glass of the tank. The thermometer will help you to monitor and maintain a suitable water temperature that directly affects the fish’s health by indicating the current temperature with a blue line on the reader.

Changing the Tank Water

It is important for you to maintain a constant temperature within the optimal range in order to keep the fish healthy. A good rule of thumb is to adjust the water temperature by 10 per hour until you get the desired temperature. When doing a water change, it is usually recommended to make use of a water conditioner.

It is also important to note that sudden/drastic change in water temperature can cause temperature shock on goldfish. It might even kill the fish if it is extreme. That is why it is recommended that the new water should be within 2degrees of the initial water in the tank when performing a water change.

Symptoms of temperature shock include: Rapid breathing, floating aimlessly, Sitting at the bottom, Excess slime production and surface gulping.

After experiencing some sequence of temperature fluctuations, it is a good idea to make use of a good quality filter bacteria supplement to help re-establish your culture as fast as possible.

Related Questions?

How to tell if your goldfish is getting enough oxygen?

Answer; Goldfish, like any other fish requires enough oxygenated water to survive. You need to be observant to watch the behavior of the fish. Anytime the oxygen level in the water is low, the goldfish will swim to the surface of the water periodically to gulp for air.

You can agitate the water in the tank and allow it to settle and watch the goldfish again. If the fish continues gulping, you may need to change the water or get a bigger tank. Sometimes, increasing the water flow will solve the problem.

What is the required PH Level for Goldfish?

Answer; A goldfish can tolerate a huge PH range. However, the goldfish do not adapt quite well to extreme or sudden changes in the PH level. According to research, the recommended PH range for goldfish is 6.0 – 8.0. This means that the goldfish can survive in water that is slightly acidic or slightly alkaline. A ph meter can be used to measure the acidity or alkalinity level. More: Lower pH in Aquarium NaturallyOpens in a new tab.

What is the right feed for Goldfish?

Answer; The food quantity and quality is a key to proper goldfish care. It has a direct effect on your fish. Analysing the Goldfish food, it was found to contain more carbohydrate than others and it also contains less protein than other fish foods.

There are already made goldfish foods available in local pet shops, so you should not just pick up any food. They are available in flakes, pellets or mixture of both.

There are some factors to consider before deciding the type of food to go for. You need to consider their size, pollution, and the nutritional value. In their natural habitat, they eat plants, insects and crustaceans. You can also try to feed your goldfish food that is similar to what they would eat in their natural niche.

What do you Think?

Having gone through this article, we hope you have been able to get some new insights about the best water temperature for your goldfish.

Have you tried anyone out and you want to share it with us?

Let us know what you think, leave your comment in the section below!

Saurabh Kumar

I am a passionate fish keeper, with years of experience. You will find some really useful tips and information on this blog about Freshwater Aquariums.

Recent Content