Bettas (Siamese Fighting Fish) have evolved in a tropical habitat with warm water year-round. As a responsible fish owner, you should know everything about fish tank temperatures to ensure your fish live in a healthy environment.
Let’s dive into the topic of betta fish and their ideal temperature range, the absolute minimum and maximum temperatures for betta fish, and what you should do if the temperature changes.
Ideal water temperature for betta fish tank
The ideal water temperature range the betta fish needs to live a happy life is 76-82°F (24-28°C), or 75-80°F is easier to remember.
Experts disagree about the exact temperature. Some say room temperature; some say 78 to 80 or 76 to 82; others 77 to 81. The fish are not sensitive to changes of a degree or two in their natural habitat, so don’t worry about it. But an ideal temperature that is easy to remember would be a range of 75-80 degrees Fahrenheit. Bettas can develop a tolerance for slightly colder temperatures but need a long time to acclimate.
Also, consider the depth of the water. In a deep tank, warm water rises to the top, and the bottom water is colder. Siamese Fighting Fish prefer relatively shallow and stagnant water. The ideal water depth is about 12 inches or 30 centimeters, which makes it easy for them to swim from the bottom of the tank to the surface. If you have a large and deep tank, consider adding levels or platforms where one part of the tank is shallower to allow for a suitable betta habitat.
Betta Fish Minimum and Maximum Water Temperature
Minimum water temperature
The minimum water temperature that a betta can tolerate is 72 degrees Fahrenheit or 22 degrees Celcius, but it is not ideal.
The absolute minimum water temperature that a betta fish can survive is 65 degrees Fahrenheit or 18 degrees Celcius, but this is dangerous for the health and well-being of your beloved pet fish and can have fatal consequences.
Maximum water temperature
The maximum water temperature for a betta fish is 82 degrees Fahrenheit or 27-28 degrees Celcius.
A betta’s absolute maximum water temperature that it can survive is around 86 degrees Fahrenheit or 30 degrees Celcius, a dangerous water temperature for betta fish that can cause them to boil to death slowly.
The risk of exposing bettas to extreme temperature
Maintaining stable temperatures in the betta tank is crucial for their health. Bettas are tropical fish, and extreme temperatures can be dangerous or lethal.
Colder water can lead to symptoms such as not eating, depression, and death from hypothermia. Cold water can worsen the fish’s immune system and increase their risk of diseases. How cold is too cold? 70°F is too low. Any lower than this can kill your betta.
On the other hand, too hot water can cause distress, heat shock, and death by organ failure. Also, sudden temperature changes can cause pain, and you want to keep fish calm and relaxed. How warm is too warm? 84°F is too warm.
Symptoms that the water is too cold or warm
If you don’t have a thermometer, you should get one. If you break your meter and wonder if your fish are OK, you can look for a few symptoms and signs.
Symptoms of low temperature are that your betta is sluggish, lethargic, lazy, depressed, and not eating much.
Symptoms of high temperature are similar: the betta seems to be suffering, inactive, with clamped fins, and a loss of appetite.
How to properly acclimate betta fish to a new temperature
When you acclimate a betta fish to new temperatures and water conditions, it’s crucial to do it slowly and carefully.
The number 1 crucial step is to use old water from the tank where the betta currently lives, mix it with a small amount of new water (aquarium water from the betta’s new home), and gradually increase the amount of new water to allow for a smooth adjustment.
For example, if you introduce a betta to your tank from a water bag, don’t be careless and release it into the tank without doing the necessary acclimation process. Let the water bag containing the betta float on the tank for at least 15 minutes so that the temperature in the waterbag slowly changes and lets the fish adjust to the temperature. Then add small amounts of aquarium water into the bag every five minutes. After about 30-45 minutes, the bag’s water contents and temperature are almost identical to the new tank, and you can safely release your betta to the new tank. This process dramatically reduces stress and allows for gentle adjustment without any shock.
Tips for maintaining a suitable water temperature for your betta
Maintain an ideal betta temperature range between 75-80°F by following these tips
- Use a thermometer to monitor the water temperature. Water holds on to heat longer than air and releases heat more slowly than air, so there can be a difference between room temperature and water temperature. Using a thermometer in the water is the best way to get a proper reading so you can adjust the temperature when needed. Prevent the water from getting too cold or too warm.
- Use a heater to adjust the temperature. If your room has a heat pump, you can set it to a fixed temperature like 76°F or 24°C. If you don’t have a heat pump, you can use a heater or a water heater or install an aquarium heater.
Frequently Asked Questions about Bettas Aquarium Temperature
What Is Temperature Shock?
Temperature shock is when a fish experiences sudden changes in water temperature, which causes significant distress to the fish and can cause pain, suffering, or death.
How to Prevent and Avoid Temperature Shock?
You can prevent temperature shock by monitoring and adjusting the aquarium water temperature. Always follow a careful acclimation process when changing water or moving the betta from one place to another. If you are a responsible fish owner and act patiently by gradually allowing your fish to acclimate, you can avoid shock, stress, and suffering.
What Causes Rapid Temperature Changes in a Fish Tank?
Rapid water temperature change is often caused by significant fluctuations in room temperature, changing aquarium water, or moving the fish from one water tank to another.
Is Temperature Shock Fatal for Bettas?
Sudden temperature falls or jumps can cause distress and suffering and can be very dangerous to the point of killing a fish in extreme cases.
I lost power, and my heater is not working. Will my betta be OK?
If you lose power and the heater is not working, you should monitor the water temperature of your betta tank. Even if room temperatures drop by a few degrees, it usually takes longer for the water temperature to drop since water holds on to heat and releases it more slowly. If the power outage is temporary, and the water temperature doesn’t drop below 76°F or 24°C, your betta should be OK. Suppose it drops below 75°F and the water heater does not work. In that case, you may want to move your betta into a smaller container of warmer water (by slowly acclimating it to the warmer water over 30 minutes) and keep it there until you get the heater fixed or the power comes back on.
I lost power. How do I keep my betta fish warm without a heater in an emergency?
Check the water temperature. If it is within the range of 76-82, you can insulate the water tank to hold onto heat for longer until the water comes back on. You can use an aquarium blanket or wrap your fish tank with a duvet, blankets, or towels.
If your power is off for a long time, and you don’t see any chance of it coming back on for a few hours, and the water temperature drops below 70, you may be facing an emergency scenario.
In an emergency where you don’t have any other heat source, you can fill a smaller plastic bag with water from the tank and put your fish in the bag together with a thermostat. Then gently hold the water bag close to your body with an insulated jacket or thick blanket over you to keep the water warm. You use your body heat until the power returns or find another heat source. Monitor the thermometer and check on your fish often.
How hot can betta fish water be?
The hottest water temperature a betta fish can live in is 82 degrees Fahrenheit or 27-28 degrees Celcius. The absolute maximum temperature a betta fish may survive is around 86 degrees Fahrenheit or 30 degrees Celcius which can cause suffering and death.
How cold can betta fish water be?
The coldest water temperature a betta fish can live in is 72 degrees Fahrenheit or 22 degrees Celcius. The absolute minimum temperature a betta fish may survive is around 65 degrees Fahrenheit or 18 degrees Celcius which can cause health problems or a fatality.