What Temperature Do Goldfish Like? {Temperature Shock Symptoms}

Goldfish have specific preferences when it comes to water temperature. Let’s explore what temperature do goldfish like.

In this article, we will discover the ideal temperature range that goldfish prefer for their well-being.

By understanding their temperature needs, we can provide them with a comfortable environment to thrive in.

What Temperature Do Goldfish Like?

Goldfish generally prefer a water temperature between 65°F and 75°F (18°C and 24°C). This temperature range is suitable for most common goldfish varieties, including:

  • comet goldfish
  • fantail goldfish
  • oranda goldfish

Maintaining a stable water temperature within this range is crucial for the health and well-being of goldfish.

Sudden temperature fluctuations or extremes can cause stress and negatively impact their overall health. Regular monitoring of the water temperature is recommended to ensure it remains within the preferred range for goldfish.

How Can I Measure the Water Temperature for My Goldfish?

To measure the water temperature for your goldfish, you can use a reliable aquarium thermometer.

These thermometers are specifically designed to be submerged in water and provide accurate temperature readings. There are various types available, such as:

  • adhesive strip thermometers that can be attached to the outside of the aquarium
  • digital thermometers with probes that can be placed directly in the water

Ensure that the thermometer is placed away from direct sunlight or any heat sources, as this can affect the accuracy of the readings. Regularly check the thermometer to ensure the water temperature remains within the ideal range for goldfish.

What Should I Do if the Water Temperature Is Too High for My Goldfish?

If the water temperature in your goldfish tank is too high, there are several steps you can take to lower it. First, turn off any heating devices or lights that may be contributing to the increased temperature.

You can also partially cover the aquarium to reduce the amount of direct sunlight reaching the water.

  • Add cool water to the tank gradually.
  • Make drastic temperature changes, as this can stress your goldfish.
  • Monitor the temperature closely and make gradual adjustments until it falls within the preferred range.

If you live in a region with consistently high temperatures, consider using a chiller or fan to maintain a suitable temperature for your goldfish.

What Should I Do if the Water Temperature Is Too Low for My Goldfish?

If the water temperature in your goldfish tank is too low, it’s crucial to take steps to increase it gradually.

Check if there are any drafts near the aquarium and ensure it’s not placed in a cold room.

  • You can use a reliable aquarium heater to warm up the water slowly.
  • Choose a heater appropriate for the size of your tank and follow the manufacturer’s instructions for installation.
  • Increase the temperature gradually by a few degrees each day until it reaches the desired range for goldfish.

It’s important to avoid sudden temperature changes, as they can be stressful for your goldfish and negatively impact their health.

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What Are the Signs of Stress in Goldfish Related to Water Temperature?

Goldfish may exhibit signs of stress if the water temperature is not suitable for them. Some common indicators of temperature-related stress include:

  • lethargy
  • loss of appetite
  • rapid breathing
  • clamped fins
  • unusual swimming behavior

If you notice any of these signs, it’s essential to check the water temperature and ensure it falls within the preferred range for goldfish.

Other factors like water quality and compatibility with tankmates should also be considered.

Providing a stable and appropriate environment, including the right water temperature, can help alleviate stress and promote the well-being of your goldfish.

Can I Use Ice Cubes to Cool Down the Water Temperature in My Goldfish Tank?

Using ice cubes to cool down the water temperature in your goldfish tank is not recommended. While it may seem like a quick and easy solution, it can lead to sudden and drastic temperature changes, which can be harmful to goldfish.

  1. Rapid temperature fluctuations can cause stress and compromise their health.
  2. It is better to address the underlying issue causing high water temperature, such as:
  • adjusting the room temperature
  • reducing direct sunlight
  • using a reliable aquarium chiller

If you find the water temperature consistently exceeds the recommended range for goldfish, investing in an aquarium chiller specifically designed to cool the water gradually and maintain a stable temperature is a safer and more effective option.

What Are the Risks of High Water Temperature for Goldfish?

High water temperatures can pose risks to the health and well-being of goldfish. When the water temperature exceeds the suitable range, typically above 75°F (24°C), it can lead to various issues.

  1. Elevated temperatures reduce the amount of dissolved oxygen in the water, affecting the goldfish’s ability to breathe properly.
  2. It can also increase the metabolic rate, causing the fish to become more active and stressed.
  3. Higher temperatures can promote the growth of harmful bacteria and increase the risk of diseases.

Goldfish may also experience:

  • loss of appetite
  • lethargy
  • increased susceptibility to infections

To prevent these risks, it’s important to monitor and regulate the water temperature within the recommended range, ensuring a stable and comfortable environment for the goldfish.

Goldfish Temperature Shock Symptoms

Goldfish temperature shock symptoms can vary depending on the severity and duration of the temperature change. Here are some common signs to look out for if your goldfish has experienced temperature shock:

  1. Lethargy: Goldfish may appear sluggish and less active than usual. They may spend more time at the bottom of the tank and exhibit reduced interest in their surroundings.
  2. Loss of appetite: Temperature shock can affect a goldfish’s appetite, leading to a decrease or complete loss of interest in food. They may refuse to eat or show disinterest in their usual feeding routine.
  3. Erratic swimming behavior: Goldfish may display abnormal swimming patterns, such as darting around the tank or struggling to maintain balance. They may also exhibit difficulty in maintaining a normal upright position.
  4. Gasping for air: In cases where the water temperature is too high, goldfish may gasp for air at the water surface due to decreased oxygen levels. This is a sign of distress and indicates that the fish is struggling to breathe properly.
  5. Fins clamped close to the body: When experiencing temperature shock, goldfish may clamp their fins tightly against their body. This is a defensive posture and can indicate stress or discomfort.

If you observe any of these symptoms in your goldfish after a temperature change, it’s important to take immediate action.

Goldfish Water Temperature in Winter

Maintaining the right water temperature for goldfish during winter is crucial to their well-being. Here are some important considerations:

  1. Insulate the tank: Place the goldfish tank away from drafty areas or windows to prevent exposure to cold air. Insulating the tank with a tank cover or wrapping it with a towel or insulating material can help retain heat.
  2. Monitor room temperature: Ensure the room where the goldfish tank is located stays at a comfortable temperature. Avoid extreme temperature fluctuations, as they can impact the water temperature.
  3. Use a heater: In colder climates or if room temperatures drop significantly, consider using an aquarium heater. Select a heater appropriate for the size of your tank and set it to maintain the recommended water temperature range for goldfish (typically between 65°F and 75°F or 18°C and 24°C).
  4. Check water temperature regularly: Use a reliable aquarium thermometer to monitor the water temperature frequently, especially during winter. Make adjustments to the heater if needed to ensure the temperature remains within the suitable range for goldfish.
  5. Be mindful of power outages: During winter storms or power outages, it’s essential to have a backup plan in place. Consider investing in a battery-powered air pump and an emergency heat source, such as hand warmers or a generator, to maintain adequate water circulation and temperature.

By implementing these measures, you can help ensure that your goldfish remain comfortable and healthy throughout the winter season.


Goldfish thrive best in water temperatures between 65°F and 75°F (18°C and 24°C). This temperature range is suitable for most common goldfish varieties, including comet goldfish, fantail goldfish, and oranda goldfish.

Maintain a stable water temperature within this range to ensure their health and happiness.

Regular monitoring of the water temperature and making necessary adjustments will help create an ideal environment for goldfish, promoting their overall well-being in the aquarium.

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Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.