What is the Optimal Betta Fish Water Temperature?

Betta fish are one of the most popular pets in America. They are easy to take care of, and they can even live in a small bowl! But how often do you think about their water temperature? It is important to have an ideal water temperature for your betta fish because it affects their health.

What is the Optimal Betta Fish Water Temperature?

The optimal betta fish water temperature is between 78-82 degrees Fahrenheit. To stop the water temperature from falling below this range, you will need to use a heater or get a thermometer so that you can adjust the temperature accordingly.

Temperatures below 78 degrees or above 82 degrees can be dangerous for your betta and can lead to health problems. The water must be kept in this range to keep your betta happy and healthy.

This fact highlights just how sensitive betta fish are to temperature and why you should only keep one as a pet if you are willing to take care of them properly.

Luckily, there are many advanced heaters that are designed to regulate the water temperature for your fish. They don’t have to be expensive, either. You can find a quality heater for around $30 at most pet stores or via an online retailer.

Why Do Betta Fish Need Warm Water?

Betta fish are native to the tropics of Asia, which means that they are used to warmer water temperatures than the average household aquarium provides. They need warm water to mimic their environment in shallow rice paddies.

If their water is cold, then it can affect your betta’s organs and cause them to shut down. In fact, if the water is too cold, then your betta fish could even die from shock. So it is important to make sure that you keep their water at a temperature that is comfortable for them!

Is 84° Too Hot for a Betta Fish?

Betta fish will survive in water temperatures of 84 degrees Fahrenheit. However, they will not be as healthy in these conditions. The ideal water temperature range is 78-82 degrees Fahrenheit because it’s not too hot or too cold.

Betta fish living in temperatures of 84 degrees Fahrenheit will show signs of being uncomfortable and stressed, like swimming erratically and gasping for air at the surface.

The number of oxygen molecules in hot water is lower than that in warm water. This means that your betta will start to suffocate in water that is too hot. As they start to panic, their metabolism will go into overdrive, which then leads to other health problems.

So while your betta will survive in water temperatures of 84 degrees Fahrenheit, it is not the best environment for them. Try to keep the water temperature within the ideal range of 78-82 degrees so that your fish can be happy and healthy!

Can the Temperature Fluctuate?

No, betta fish are from an environment where the water temperature does not fluctuate. As such, ensure your betta’s water is not affected by the seasons in your country.

Temperature shock can be fatal to your betta, so take care when adjusting the temperature of their water. A sudden change in water temperature can cause your fish to become ill or even die.

When changing the water temperature, make sure that you do it gradually over a period of 24 hours. This will help your betta get used to the new environment and prevent them from getting sick.

You would be surprised at the number of people who replace all of the tank water at once, thinking that it’s okay because the heater will keep the new water warm. This is not true, though! They are likely to get sick or even die from this type of shock because it’s too sudden and their bodies aren’t prepared for it.

A tank close to the window may become too cold in winter and too hot in summer. If you must keep your tank near a window, use blinds or drapes to protect your tank.

This also highlights the importance of using a thermometer that you can rely on. In fact, some fish owners even use two thermometers, which reduces any risk from a faulty product.

Should I Use a Heater for My Betta Tank?

Yes, it’s important to use a heater for your betta tank to stop the water temperature from falling below 78 degrees Fahrenheit. A good quality aquarium heater will keep the water at a comfortable temperature for your fish and help to extend their life.

Not using a heater is simply risking your betta’s health and could lead to death. Luckily, there are many affordable aquarium heaters on the market, so there is no excuse not to have one!

If you are having trouble keeping your betta fish’s water at the correct temperature, then please consult an expert or visit a pet store for more information. Maintaining the correct water temperature is essential to your betta’s health and well-being, so don’t take it lightly!

Recommended Tank Heaters for Betta Fish

Here are our recommended tank heaters to maintain constant temperature for your Betta fish. Fortunately, all are relatively inexpensive:

Best Budget / Starter Heater for Small Tanks (1-3 Gallon):

Aqueon Small Aquarium Fish Tank Submersible Mini Flat Heater Up to 2.5 to 5 Gallon Aquariums, 7.5 Watts
  • Fully submersible
  • Vertical or horizontal placement using suction cups that mount to the bottom or side wall of tank
  • Quick and easy installation
  • Shatterproof construction
  • Can be used with glass or acrylic enclosures

Best Preset Heater for Medium Tanks (up to 30 gallon):

Aqueon Aquarium Fish Tank Preset Heater For Up To 40 Gallons, 100 Watts
  • Preset to 78 degree, accurate to plus/- 1 degree
  • No adjustment required
  • Shatter resistant
  • Fully submersible, auto shut-off when overheats, resets when cools down
  • LED light turns on when aquarium water is being heated

Best Adjustable Heaters for Medium and Large Tanks (up to 75 gallon):

Hitop 25W/50W/100W/300W Adjustable Aquarium Heater, Submersible Glass Water Heater for 5 – 70 Gallon Fish Tank (300W)
  • Wide Application: 300W aquarium heater, length: 11*1*1 in (27*2.5*2.5 cm), suitable for 35-70 gallon aquariums, also suitable for seawater and freshwater, can be used in fish tanks and turtle tanks.
  • Safe: Explosion-proof glass heater, this fish tank heater is made of 2mm thickened quartz glass, 33% thicker than ordinary glass, not easy to crack, which is very safe for people and aquatic animals.
  • Adjustable Temperature: This fish heater adopts 8-slot multi-branch heating wire ceramic frame, better heat dissipation, long service life. The adjustable temperature range of the water heater for fish tank is 68°F - 93°F (20°C - 34°C), and we also included a thermometer sticker, which is more convenient to check the water temperature.
  • Complete Accessories and Warranty: This aquarium submersible heater comes with all the accessories you need, except for a stick-on thermometer, it also comes with 3 suction cups, one for replacement. We provide a 12-month warranty service for this heater, so you can buy with confidence, if you have any questions, please feel free to contact us, we will reply within 24 hours.
  • Note: This fish tank heater must be fully submerged in water for use. If you need to change the water or clean the fish tank, please cut off the power first, cool the heater for more than 15 minutes, and then take it out after the heater is completely cooled.
Orlushy Submersible Aquarium Heater,500W Fish Tahk Heater with Adjust Knob Thermostat 2 Suction Cups and Free Thermometer Suitable for Marine Saltwater and Freshwater (500W)
  • ★Adjustable Aquarium Fish Tank Water Heater Sensitive and reliable thermostat maintains uniform temperature. Automatic shut off when the temperature is reached
  • ★500W aquarium heater is suitable for 40 to 75 gallons aquariums,voltage 110-120V, power cord is 6ft, please choose the right wattage aquarium heater according to our size chart.
  • ★Explosion Proof: 2mm thickened quartz glass,can be used in fresh water and salt water aquariums,easy to hide in the tank.
  • ★Precise temperature dial from 68 to 89°F allows for complete control of aquatic climate within a 1-degree difference.

Is My Betta Too Hot?

If you have a heater in your tank and the water temperature is above 82 degrees Fahrenheit, then you need to turn it down. Bettas can’t tolerate water temperatures much higher than 82 degrees Fahrenheit.

Betta fish living in these conditions will be uncomfortable and may even die from heatstroke. You should also use a thermometer to make sure that the water temperature is not getting too high.

You’ll know if your betta is too hot if he is lying at the bottom of the tank, floating near the surface, or swimming around erratically. If you see these signs, then take action immediately.

Is My Betta Too Cold?

If the water temperature is below 78 degrees Fahrenheit, then you need to turn up your heater. Unlike humans and other animals, betta fish cannot tell when they are too cold; it affects them slowly over time.

Betta’s living in these conditions will begin to show signs of stress as their bodies start shutting down. They may even experience seizures.

You should also use a thermometer to make sure that the water temperature is not getting too low. If you notice your betta fish shivering, hiding in plants or under rocks, then they are feeling the effects of being too cold.

Water that is too cold will cause your betta to become lethargic, stop eating, and be vulnerable to infection and disease from a weakened immune system. You can learn more about cold water and bettas here.

How to Keep Betta’s Water at the Correct Temperature?

Keep your betta’s water temperature between 78-82 degrees Fahrenheit by using a heater or thermometer.

Using a heater is best for keeping the tank at an even temperature because it will automatically adjust as needed. In reality, a heater is a MUST if you want to keep a betta fish healthy.

A premium thermometer is also important for keeping the water at the right temperature. You should get one that attaches to your tank, so you can easily read it when needed.


In conclusion, there are many important factors to consider when caring for betta fish. One of the most critical aspects is maintaining their water temperature in a range between 78-82 degrees Fahrenheit.

If you want your betta fish to be healthy, then it’s essential that they live in warm enough conditions! Not using a heater or thermometer can risk your betta’s life, so be sure to take the necessary precautions.

So what are you waiting for? Get a heater and thermometer today and start providing your betta with the best possible care! Then, get to decorating your betta fish’s home to make it fun and festive.