Is 84 degrees too hot for a betta fish?

In this blog, we will discuss whether 84 degrees is too hot for a betta fish.


In this blog

  • Is 84 degrees too hot for a betta fish?
  • Why 84F is not suitable for bettas?
  • How to deal with such higher temperatures in a bettas tank?
  • What are the signs that higher water temperature is stressing your betta fish?
  • Summary 
  • Frequently asked questions
  • Reference

Is 84 degrees too hot for a betta fish?

Betta fish need a temperature between 76-80 degrees Fahrenheit to survive. They are happiest living in warm water in their natural environment and prefer the same temperature and environment in their artificial environment. Here an artificial environment means home aquariums. 

Being a hardy species, bettas can survive under severe conditions, but anything extreme can be harmful to their health overall. They can tolerate slight variations but extreme temperature variations can be stressful and life-threatening.

If the temperature in your aquarium goes beyond 80 F or below 76F, bettas can still manage. But if the temperature goes up to 84F or 70F, it can stress your fish. 

Stress is one of the main contributors to the death of an aquarium fish. And if your fish are under pressure, they’ll attract all kinds of infections, which may weaken their immune systems and eventually kill them.

Why 84F is not suitable for bettas?

Betta fish are one of the most aggressive aquarium fish and have the reputation of fighting with their kind and other species as well. Due to their fighting tendencies, they are kept in solitary tanks to avoid such confrontations.

Even if they are kept in solitary tanks, they are surrounded by a variety of organisms, especially the beneficial bacteria that are very important to them and the tank environment.

Bacteria have a temperature limit that allows them to live and work properly. If the temperature goes too high or drops too low, these bacteria can die.

Bacteria can help to suppress ammonia spikes in the tank, keeping your betta fish happy and healthy. If the temperature in the tank goes up to 84 degrees Fahrenheit, the beneficial bacteria will be killed and this will increase the levels of ammonia in the tank, which is known to be harmful to bettas’ health.

How to deal with such higher temperatures in a bettas tank?

Caring for a betta fish is not difficult, as long as you have a plan and the right solutions to common aquarium problems. If you are a responsible betta owner, you will make sure you are following the guidelines for tank care and taking care of your fish’s needs.

So, now we know the repercussions of a higher temperature like 84F to your betta’s health. But you should not panic if this happens once because there is a solution for every problem.

The very first thing to do if your tank temperature is beyond a certain limit is to use cold water or a few ice cubes in a water bag or some bag and float that on the surface of the water for some time until the temperature becomes suitable for your betta fish again.

When you are using cold water or ice cubes to cool down the temperature, be sure to not add the cold water or ice cubes directly into the betta’s water. Doing so can be stressful for your fish.

The second most important part of a betta tank is a heater and thermometer. Heaters are important for bettas’ health and keeping the tank at the proper temperature. If you don’t have a heater and a thermometer to keep and monitor Bettas’ temperature, Bettas will die from heat shocks.

If you want to reduce the higher temperature, turn off the heater in the betta’s tank for some time until the situation is suitable again for your fish.

The third thing which you can do is turn on the air conditioners in your room for some time to cool down the temperature. If you have specific fans for aquariums, you can use those to do the same.

The last thing you can do is change the water in the betta’s tank. Make sure you are doing this properly. Bettas sometimes die due to sudden water changes. So before performing this you plan everything to avoid shocks due to high temperature and water change shocks. This step is critical, so acclimate your betta fish properly before adding the fresh water to the tank. 

Directly adding them to fresh water can kill them after water changes due to water chemistry differences. Therefore, be very careful whenever you are doing this.

What are the signs that higher water temperature is stressing your betta fish?

If you’re keeping betta fish, be sure to keep an eye on their behavior in case any problems develop. Any minor or major inconvenience can be detected this way. Fish can communicate with you by displaying what is troubling them in their aquarium.

Signs that higher water temperature is stressing your betta fish are:

  • Bettas will be seen gasping rapidly on the surface of the water continually.
  • Bettas usually occupy the upper and middle levels of the tank and swim in those areas only. They have labyrinth organs, which help them to survive in oxygen-deficient environments. But extreme temperatures make them uncomfortable and they are always seen on the surface of the water.
  • Higher temperatures will lead to an increase in ammonia levels in the tank, which can cause gill burns in bettas. This may be alarming. If it is not monitored in time, bettas will die of burns. If the gills don’t work, your betta fish won’t be able to swim properly.
  • Betta fish will stop eating because of high temperatures. The bettas will lose interest in food. Bettas can live without food for 2-3 days, but beyond 3 days they may die.
  • The betta fish enjoy swimming around the tank by showing off their beautiful fins, but because of high temperatures, they succumb to various infections which make them weak and they lack the energy to swim the way they used to swim.
  • As the water temperature rises, your betta fish will start losing their coloration.
  • Extreme water temperatures are directly correlated to bettas age. If the water temperature exceeds the normal range, your betta fish has a shorter life span. A betta fish with an average lifespan of three years will only live for a year or so if they are kept in hotter temperatures.


It is now clear that 84°F is too hot for betta fish to thrive. Your beautiful betta fish need a temperature range of 76-80 degrees for survival. If you do not keep the ideal temperature in your fish’s artificial environment, they could die out of stress.

Installing a heater is essential to keep your betta fish healthy and happy. Monitoring tank temperature is equally important to know the fluctuations.

Make a habit of checking betta fish aquarium temperature every day to avoid health concerns. If you are too busy to monitor every day, you can connect heaters with a thermometer that can alert you when the temperature rises or drops.

If you want betta fish, make sure you’ve studied all about them before you get them. If you can’t give proper attention and care then kindly don’t get one.

Keep in mind:

  • Bettas are tropical fish.
  • They prefer warm water conditions in their tank.
  • Use a thermometer to maintain the temperature between 76-80F. 
  • Betta fish can die from temperature fluctuations, temperature shocks, and extreme temperatures.
  • Avoid ammonia pollution in bettas tanks.
  • Beneficial bacterias are essential to bettas.
  • Bettas can die after sudden large water changes.
  • Higher temperatures can affect bettas’ coloration.
  • Higher temperatures can affect bettas swimming patterns.
  • Higher temperatures can affect their lifespan.
  • Higher temperatures weaken bettas immune system.
  • Such extreme temperatures make it difficult for bettas to breathe.
  • Heaters are essential for bettas but you need to turn off the heaters when the temperature goes up beyond 80F.
  • Monitor your fish swimming patterns every day.
  • If your fish is not moving, staying at one place or on the surface for a long time, it is time to check water temperature and other water parameters too.
  • Give the best possible care to your betta fish to avoid such situations. If you can’t afford a betta fish then kindly don’t get one.

Frequently asked questions

What is the right water temperature for betta fish?

The right water temperature for betta fish is between 76-80F.Anything extreme can be stressful and fatal for your betta fish.

Are bettas hardy species?

Yes, bettas are hardy species and can survive in harsh conditions. 

Will the extreme temperatures affect the bettas immune system?

Yes, extreme temperatures weaken bettas immune system and make them more susceptible to various infections.

Are higher temperatures harmful to beneficial bacteria in bettas tanks?

Yes, higher temperatures can kill beneficial bacterias in bettas tanks.

Are higher temperatures responsible for ammonia spikes in bettas tanks?

Yes, higher temperatures can increase ammonia levels in bettas tanks by killing beneficial bacterias.