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The Ideal Betta Fish Temperature Range and Why It Matters

Are you keeping your betta at the right temperature? Depending on their species, various betta fish require different water temperatures. And if your betta is living in an aquarium with the incorrect temperature, it can be detrimental to their health—or even cause death.

In this article, you’ll learn what happens to your better fish when the water temperature isn’t right, how to maintain the right temperature, and what to do if things go wrong.

Betta Fish Temperature Sensitivity

Being cold-blooded, bettas rely on a specific water temperature to survive. In the wild, bettas live in tropical waters with a stable water temperature of 75-80 degrees Fahrenheit (24-27 degrees Celsius), so it’s important to duplicate this temperature for optimal care.

What Is the Ideal Temperature Range for Betta Fish?

The ideal betta fish temperature is 75-80 degrees Fahrenheit (24-27 degrees Celsius).  This is the temperature range of the tropical and subtropical waters of their natural habitat.

Having said this, there are 73 species of betta fish. And while this temperature range works fine for all species, each species has its sweet spot. The following are the most common betta species kept and their temperature preference:

Betta Splendens

Betta splendens is the most common betta species kept. It’s the domesticated version of its wild counterpart. Because they are captive-bred, we don’t have a natural temperature range for them. I recommend keeping them at a water temperature between 75-82 degrees Fahrenheit (24-28 Celsius).

Betta Imbellis

Also known as the crescent betta or peaceful beta, betta imbellis hasn’t been domesticated. It is a wild species. It is found in the marshes of Sumatra, Malaysia, and Thailand. It does best at a temperature between 72-80 degrees Fahrenheit (22-27 Celsius).

Betta Macrostoma

Betta macrostoma, also known as the Brunei beauty or spotfin betta, is domesticated, but less commonly kept. It’s found in parts of Borneo and prefers cooler temperatures, 74-76 degrees Fahrenheit (23-24 Celsius).

Betta Hendra

Betta hendra is also found in parts of Borneo, in the peat swamp forest of the region. This species prefers cooler waters, with ideal temperatures around 74-76 degrees Fahrenheit (23-24 Celsius).

🐠Discover where betta fish come from and how their roots impact their behavior and temperature needs.

What Temperature Do Betta Fish Need in Celsius?

The general temperature range for bettas is 24-27 degrees Celsius.

What Happens When the Temperature Is Out of This Range?

Water temperatures outside the range of 75-80 Fahrenheit (24-27 degrees Celsius) can lead to health issues like a slowed-down metabolism, lack of oxygen, or death. Let’s look at what happens to bettas when the water temperature fluctuates:

When the Water Is Too Hot…

If the water is too hot, your betta’s metabolism will increase.

Also because high water temperatures hold less oxygen, your betta will breathe more rapidly but consume less oxygen. This will lead to your betta spending most of its time at the surface of the water, where oxygen is more available. It also may swim erratically. All of this can create stress for them and take a negative toll on their overall health and well-being.

When the Water is Too Cold…

Your betta’s metabolism will slow down if the water temperature is below the ideal range. Your fish will become lethargic, which can lead to stress. The betta may spend most of its time at the bottom of your tank and have trouble breathing. Because the betta lacks energy, it will be more vulnerable to disease or infections.

Is 82 Degrees Too Hot for a Betta Fish?

Yes, 82 degrees is too hot for a betta fish. The ideal betta fish temperature ranges from 75-80 degrees Fahrenheit (24-27 degrees Celsius). It could lead to breathing problems, increased metabolism, hyperactivity, and burnout.

Is 75 Degrees Too Cold for a Betta?

75 degrees is a good temperature for betta fish care. The ideal temperature range for bettas is 75-80 degrees Fahrenheit (24-27 degrees Celsius).

Can Betta Fish Live In 70-Degree Water?

70 degrees is too cool for bettas. Even the colder water betta species would have a hard time adjusting. Cool water can cause your fish’s metabolism to slow, causing trouble breathing and low body function.

Temperature Shock

Temperature shock is a condition that occurs when there is a sudden change in water temperature. If the temperature fluctuation is too extreme, the betta’s body can’t function, which can lead to coma or death.

Temperature shock most frequently occurs when you introduce new fish to the tank. The water in the bag containing your betta may be at a different temperature than the tank water, which may create temperature shock.

You can avoid this by acclimating the fish before releasing it into the tank.

Temperature shock can also occur during water changes. To avoid this, ensure that the new water being introduced to the tank is the same temperature as the old water.

Signs of Temperature Stress in Betta Fish

Your betta may experience temperature stress if the water temperature is not in its ideal range. The following are signs of temperature stress to look out for:

Lethargy and No Appetite

Water temperatures that are too low will slow your betta’s metabolism. As a result, your betta may be sluggish and not eat.


Water temperatures that are too high will increase your fish’s metabolism. This can lead to hyperactivity, which can lead to stress and burnout.

Staying at the Surface

Water temperature changes can affect the oxygen levels of the tank. The drop in oxygen levels will cause your betta to hang around the surface in an attempt to get oxygen from the air.

Your Betta Appears Sick

Water temperature changes will affect your betta’s immune system. Because of this, your fish will become more vulnerable to parasites and diseases. For this reason, it will often appear to be sick.

🐠 Discover the key to a thriving betta fish! Visit our complete betta fish care guide for expert tips on creating the ideal conditions for your pet.

How to Keep the Ideal Betta Fish Temperature

We have seen how important temperature is when keeping bettas. Let’s look at how you can maintain the proper betta fish temperature.

Get a Quality Thermometer

Don’t try to save money by purchasing a cheap thermometer. The thermometer you get may be one of the most important items for your tank. Invest in a quality external thermometer so that you can monitor the tank and not rely solely on a room thermostat.

Choose the Correct Heater

Purchase a quality aquarium heater. Cheap heaters run the risk of overheating the water. When choosing a heater, you will need 5 watts per gallon. I recommend the INKBIRD Titanium Aquarium Heater.

🐠View our full guide to the best aquarium heater (tried and tested!)

Watch the Water Changes

Partial water changes should be done weekly. Only replace 5-10% of the water to avoid abrupt changes to the temperature. Make sure the new water has a similar temperature and don’t forget to use a water conditioner to remove any chlorine or chloramine the new water may contain.

🐠 Learn all about the right fish tank chemicals to use for a thriving aquarium.

Store in a Safe Place

Avoid placing your aquarium near windows, as windows that receive direct sunlight can cause temperature fluctuations. For the same reason, avoid sliding glass or frequently left open doors.

In Case of Emergencies…

I encourage you to plan for an aquarium heater malfunction or an electrical outage. If this happens, do the following: 

  • Have hot water bottles and towels handy. You can wrap the hot water bottles in the towels and place them against the tank.
  • Use tealight candles to help warm the tank.

Don’t Overlook Water Temperature

Keeping betta fish at the right temperature is often overlooked by beginner aquarists and even pet stores. But without the proper temperature, bettas are vulnerable to health issues that often end in death. I encourage you to identify the species of betta that you have and provide it with the water temperature that’s best for it.

Be sure to share your comments and experiences below and share this article with any friend who keeps betta fish.

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