Do betta fish like warm or cold water?

In this blog we will discuss bettas water temperature preferences.This blog will help new bettas owners to maintain right aquarium water temperatures in bettas tank.


In this blog

  • Do betta fish like warm or cold water?
  • Water parameters for betta fish
  • How to keep bettas aquarium water warm?
  • What happens if bettas are kept in cold water?
  • What are the symptoms of cold temperature shock in bettas?
  • What happens if the water is too hot in bettas tank?
  • How to keep a betta fish aquarium water warm without a heater?
  • Is it possible for bettas to live without an aquarium heater?
  • Thermometer for bettas tank
  • Best heaters for bettas tank 
  • Summary
  • Frequently asked questions
  • Reference 

Do betta fish like warm or cold water?

Betta is a tropical climate fish, so a heater is absolutely necessary to keep it warm.Betta is much more cold-resistant than most tropical fish, as the shallow canals and ponds in which they live can change in temperature rapidly.

Many betta fish owners don’t realize that a betta fish requires warm water, not just room temperature water of 68-72 degrees Fahrenheit. Ideally, the water temperature should be between 75-80 degrees Fahrenheit for a betta fish.

To keep the ideal water temperature constant, it is recommended to include a heater in the bettas tank.When people keep betta fish in bowls/small aquariums, they usually don’t consider heaters.But mind it, bettas don’t belong to bowls and heaters are important to bettas.

Betta fish generally need a constant temperature of 80 degrees to remain happy and healthy and the only real way to achieve this is by adding a heater.

Betta fish are sensitive to their environment and water that is too cold or too hot can cause health problems.Maintain the correct temperature in the aquarium to help keep your betta fish healthy.

Water parameters for betta fish

The ideal water parameters for betta fish are:

  • Temperature: 75°-81°F (23.8°-27.2°C)
  • Ammonia and Nitrite: 0 ppm.
  • Nitrate: <20 ppm.
  • GH: 3-4 dGH (50-66.7 ppm)
  • KH: 3-5 dKH (53.6- 89.4 ppm)
  • pH: 6.5-7.5.

How to keep bettas aquarium water warm?

The ways to keep bettas aquarium water warm are:

  • One of the easiest ways to keep bettas water warm is to use a hood or canopy for the tank.
  • In order to keep the water warm for the bettas, you need to install a heater in her aquarium.
  • If your betta tank is less than 2.5 gallons, you can use a 7.5 watt heater pad underwater.
  • For tanks larger than 2.5 gallons, use a 25-50 watt submersible aquarium heater.

What happens if bettas are kept in cold water?

Betta is a tropical fish that prefers warm water.Putting them in cold water is like trying to freeze it.Putting them in cold water can make the bettas much slower or even stand still.

If a betta is placed in cold water conditions, it will not die immediately. However,since you have deprived them of their ideal living ecosystem, they will not be able to stay healthy or survive for more than six months.As tropical fish, they are susceptible to various life-threatening diseases in cold water.

The best treatment for temperature shock is to adjust the temperature to a safe range. Do this slowly. If your betta just got hit with cold water so you pour hot water into the tank to equalize the temperature, your betta may get worse.

Betta fish are cold-blooded, they can only absorb warmth from water, unlike mammals that generate their own heat. If the water is too cold to do this, they often stop moving. The cold generally makes it difficult for them to swim and move, so they avoid it as much as possible.

What are the symptoms of cold temperature shock in bettas?

Temperature shock occurs when the temperature of the water changes abruptly.If the fish cannot adapt, or if conditions do not improve, their body stops functioning properly and starts to shut down. 

Thermal shock can occur when temperatures deviate too quickly or deviate too much from ideal conditions.This can happen when temperatures get too cold or too hot,although cooler temperatures are more likely to cause bettas.

One of the best ways to tell if a betta fish is under temperature shock is to check the temperature of the tank with a proper thermometer.If the water temperature is significantly out of the ideal range, you may be dealing with an ill betta fish.

The symptoms of cold water temperature shock in bettas are:

  • Bettas rest at the bottom of the aquarium. 
  • Bettas fall into a coma.
  • Bettas get sick more often. 
  • Bettas breathe rapidly. 
  • Bettas stay on the surface of the water. 
  • Irregular swimming patterns.

What happens if the water is too hot in bettas tank?

The ideal temperature for bettas is 75-80F. However, it can withstand high temperatures of 85 F and low temperatures of 76F. Below 74F, temperature shocks begin to notice a rapid effect on bettas, and above 86 F, they slowly roast in water and die.

Hot water can cause your fish to swim too fast.Your betta will naturally float to the surface of the tank to breathe,but if the water is too hot, your betta may surface more frequently to breathe.Warm water doesn’t have as much oxygen, so your betta won’t get enough oxygen without overbreathing.

How to keep a betta fish aquarium water warm without a heater? 

  • By using a smaller aquarium-Smaller betta tanks get warmer more quickly than bigger betta tanks. 
  • By turning on the heater in your home- If you have a heater at your home, you can turn that on and make the temperature stable for bettas.
  • Using warm water for water changes-Whenever you’re performing water changes in bettas tank,change using warm water only.
  • By heating the water before a water change, you reduce the chance of excessive temperature changes and pockets of different temperatures forming inside the tank. 
  • While the current in your tank will quickly mix the two, one of the pockets may be enough to affect your fish.
  • Insulating the glass walls of your aquarium.
  • By gradually heating the aquarium water. 
  • Covering the aquarium with a screen top- Use a hood or lid and cover the tank to keep it at ideal temperature.

Is it possible for bettas to live without an aquarium heater?

Bettas are tropical fish, which means they live in warmer water in the wild. They require temperatures from the mid-70s to 80 degrees. If the temperature in your room is constantly kept at 70 degrees, they can manage without an aquarium heater.

One very easy way to increase the water temperature in a Betta without using a heater is to simply move the aquarium to a warmer area.Even if he gets only 5 or 6 hours of sunlight a day, this should be more than enough to raise the temperature of the water in a betta tank significantly.

Thermometer for bettas tank

For the most active bettas, it is important that their tank environment is as close as possible to their natural habitat.Since bettas are accustomed to constant tropical temperatures, it is important to have an effective betta thermometer to ensure that your pet fish are at the ideal temperature.

  • Put the thermometer in a place where you can easily read it. 
  • Side-mounted thermometers are often not accurate enough to be used.

Best heaters for bettas tank

Bettas are tropical fish that benefit from heaters that maintain a consistent water temperature in their environment


  • Fluval E Electronic Heater.
  • EHEIM Jager Aquarium Thermostat Heater.
  • Hygger Submersible Fish Tank Heater.
  • Fluval M Submersible Heater.
  • Aqueon Pro Heaters


  • Bettas need a hot, warm or room temperature tank to survive better. The temperature should be stable and the space should be ample.Therefore,it is recommended to use a heater to maintain the water temperature.
  • Aquarium water temperature should be maintained at 75-80 degrees Fahrenheit.
  • Colder water can kill bettas because their immune systems slow down and make them susceptible to illness.
  • Hotter water can make them uncomfortable and age quickly as their metabolism increases.
  • An aquarium heater should be used to maintain the temperature in bettas tank.
  • The most common symptom of temperature shock in bettas is rapid gill movement or panting. They can also quickly become lethargic or stop moving altogether, except for the movement of the gills.
  • If your betta suddenly gets into very cold water, you will most likely notice lethargy and loss of color.
  • Larger bodies of water take longer to heat than smaller bodies of water.Therefore, if the betta tank is small, the heating will be faster.

Frequently asked questions

How many heaters are needed in bettas bigger tanks?

Large bettas tanks may require a heater on either end.

How much watt of aquarium heater is needed for each gallon?

Choose a five watt aquarium heater for every gallon of aquarium water.

What do betta prefer, hard or soft water?

Bettas prefer hard water, but they tolerate a wide GH range between 5-20 DH or 70-300 ppm. Too hard water can be harmful to them.

Can we use lamps to heat bettas tanks?

Lamps are not the best choice for heating, as fighting fish do not like bright lights.