I get commissions for purchases made through links in this post. Learn more.

Do Betta Fish Need A Heater? Get The Answer Here!

So, you adopted a betta fish because its beauty attracted you. Now that it is in your home it has become a part of your family. You are concerned about its health and many questions keep running in your mind.

Am I taking good care of my betta? Is my little fish healthy and happy? And the most important one, do betta fish need a heater?

We will learn about this soon.

However, one thing is for sure that it will certainly prove beneficial to their health. It will keep their immune system strong and protect them from illnesses.

The seasons keep on changing. If there is a sudden alteration in temperature then it can affect the immune system of your little friend.

It will be best not to look for a straightforward answer to this important question. Instead, consider various factors and then decide if your betta fish really needs a heater.

Do Betta Fish Need A Heater?

Usually, Betta cannot survive in very cold environments. It preferably needs warm water. If the temperature goes below 68 degrees Fahrenheit, it is not favorable.

These fishes belong to the Southeast Asian farmlands and are thus used to warm water. The average temperature out there is approximately 70 to 80 degrees Fahrenheit. If you keep them in lower temperatures your betta will stay alive. However, it is likely to attract illnesses like:

  • Fin rot and mouth fungus
  • Dormant ich infestations
  • A bacterial infestation called “fur coat syndrome”. This can even prove to be fatal.

It might not be necessary to invest in a heater keeping in mind where you live. Nonetheless, it is beneficial. Yes, there are other options to keep your betta warm. But most fish owners are in support of a heater.

What Will Happen If Bettas Get Very Cold?

You perhaps know that fishes are not very comfortable with extreme changes. Most of them need a particular temperature range. When you take them out of their comfortable temperature range it throws them off slightly.

The same is the case with your little buddy. It is not possible for fishes to regulate body temperature the way we do. They depend on their surroundings to get the heat they need.

If there is an extreme change in temperature, anywhere below 74 degrees Fahrenheit, then it spells trouble. Your fish will experience great distress and will eventually die.

Symptoms Of Undercooled Betta

If the temperature in your tank goes below the ideal range, your betta will first become sluggish. It is because it is trying to conserve its energy as its metabolism is going down.

As the stress for your betta increases, it will then stop eating. This causes more stress on its body and as a result, its immune system keeps getting weaker.

The next change you will notice is the fading of color of its scales and skin.

It will try to stay close to the bottom of the aquarium or anywhere it gets some heat. This, however, will not help much. As its immune system has gotten weak, it will more easily attract fungal or bacterial infection.

Introducing A Heater

You can cure some of the diseases by introducing a heater and thus creating the ideal temperature in the tank. If, however, they attract a serious issue like dropsy then cure and survival will be difficult. It will be wise to introduce a heater from the beginning.

If you are concerned about your betta baby then you cannot let it stay in wrong temperature conditions. It will not be possible for you to keep a constant track of the changing temperature in the tank. It will thus be wise to invest in a tank heater.

What happens If The Temperature Is Too High?

You know what happens is bettas get too cold but what happens if they get too hot? If the temperature goes above 85 degrees Fahrenheit then your fish will begin getting overheated.

The first thing you will likely notice is that they will start swimming in a crazy way. As fishes are cold-blooded they need a temperature the same as their surroundings. The extra heat present will offer them more energy. This may sound good, but it can cause great stress and have an impact on their immune system.

However, the conditions of excessive heat are easier to handle. A good and cheap option will be to allow a fan to blow over your tank’s top. This will result in quicker evaporation and the tank will reach its ideal temperature.

A Constant Temperature Is Ideal

Not only do you need to make sure the temperature of the tank stays in the optimal range. It is equally important and helpful if you keep the temperature constant.

It is okay if there is a change by a few degrees throughout the day or throughout a particular season. It will not result in any kind of harm. But, if the temperature alters by eight degrees or more through a day, it is not good. It can be more harmful than the temperature going just slightly beyond the ideal rage.

It will thus be best to opt for a heater that keeps the temperature constant. Also, you can select a bigger aquarium for your betta fishes. As the volume of water in bigger tanks will be more the temperature fluctuations will be slow and less.

The ideal temperature for your betta pet will be 78 degrees Fahrenheit. You can easily maintain such constant temperature using a thermostatically controlled heater.

Betta Heater Buying Tips

So, if you’re still asking yourself the question do betta fish need a heater, then the answer is yes. Bettas will survive best if you use a heater and not just any but the best one. There are many heaters available but be careful while selecting one for your pet. You may consider the below-given tips and make your heater hunt easier.

Select One That Has A Thermostat

Though a heater is necessary, you cannot afford to overheat your tank. We already have discussed the cons of overheating your bettas. You can be more at risk if you own a small tank.

So, to be on the safer side, opt for a heater that comes with a thermostat. A thermostat will automatically turn the heater off as it reaches the pre-defined temperature. there will be no chance of overheating the tank and risking the health and lives of the fishes.

Many models come with a thermostat so the choice is large. However, many do not have one, so you need to be careful.

Glass Is Better Than Plastic

Glass tubes are the best, much more than plastic and the other choices you have.

Glass transfers heat in a better way. Also, they look better and can be cleaned without much effort. Plastic stains and discolors easily. So, you can decide which is ideal

A Completely Submersible Heater is Better

A fully submersible heater does a better job and thus makes a better choice.

If a heater does not have a completely submersible design, you pose risks. You may accidentally drop it into your tank and then invite serious problems.

Use Your Heater In A Safe Way

Video: “Aquarium heaters complete guide – all you need to know about fish tank heater”

Just investing in the right heater is not enough. You must also use it safely for the sake of your fish.


Use a thermometer. If the tank is huge you may need more than one thermometer installed. It will help you stay aware of the temperature ranges throughout your aquarium.


Keep checking the temperature once in a few hours. Also, check it right after you get up and before you go to bed. Heaters are but machines and can go faulty. You naturally will not want to run risks, so being aware is important.


Understand how the thermostat of your heater works. Some have a temperature setting option, others just let you select ‘less’ or ‘more’. In this case, you should not give the setting over a one-fourth turn at a time. If you make too high an adjustment and forget to keep track then you are inviting trouble. The heater may make the temperature reach fatal levels before going off.


Before plugging the heater, let it stay in the water for about an hour. The same procedure needs to be followed before you turn it off and take it out. This will help the glass set a balance with the temperature of the water and prevent cracking.

5If you have chosen a semi-submersible heater, keep track of the waterline level in comparison to the level of water in your tank. the water should never go below or above this marker. If the water goes too low it may overheat the heating tube. This can result in an explosion. If it goes too high it can cause an electric shock.

What To Do In Times Of An Emergency?

So, you need a heater for your betta fish and you need to find the right one. Even if you have a heater there can be an emergency. There may be a power cut or your heater may break. Your fish cannot wait for the power to be back or for you to invest in another heater. So, you need to keep the tank warm meanwhile, and we shall help you know how.

  • If your tank is near a window take it away and keep it somewhere at the center of your house. Heat is lost through your windows. So, areas close to the windows can be comparatively cooler. This is not what you want for your bettas.
  • If, however, it is sunny outside and pretty warm inside your home, then things will be different. You need to keep the tank close to the window in such a situation. the heat of the sun will heat up your tank. However, keep a watch and do not let the tank get too hot.
  • Turn up the heat in your home. You can follow this tip if you know you can heat up your tank quite soon. This tip also works if you have a small tank. If your house is heated, the high room temperature prevents the water temperature from going low.
  • Take some water and pout it in a bag. The water should not be boiling but just hot. And you need just 10 percent water of the capacity of your aquarium. Remove 10 percent water from your tank and put the bag in. Allow the bag to float on the surface of your aquarium.
  • If you have a tank with an open-top then placing a towel over it will help preserve heat. Even if you have a lid, this tip will still keep heat.
  • You may even place towels around your aquarium in order to preserve heat. Yes, the sudden alterations in light can cause some stress to your bettas. However, it will not be as stressful as sudden dips in water temperature.
  • If you have an electric blanket you can use that as well. Do not forget to keep track of the water temperature when following this tip.
  • Many other items present in your home can prove helpful. For instance, you can blow our hairdryer at the tank. Also, you can move your lamp closer to the aquarium and let it use the light and draw some heat. These can help you for just some time and you can look for a permanent solution meanwhile.


So, do betta fish need a heater? Yes, they do, if you are concerned about their health. Yes, they do, if you want them to live long. A single betta male fish can live for more than 5 years in a properly maintained, good-sized tank. If however, you are a negligent owner, its life can go as low as 1 to 2 years or less.

A good quality heater contributes in a big way to the health of your tank and the lives within. It will help make sure there are fewer temperature fluctuations. Frequent temperature changes can cause sluggish behavior, diseases, and other issues. You surely will never want your bettas to be prey to any such problems.

Thus, it will only be fair to conclude that a heater makes an indispensable part of a tank if you are an owner of betta fish and truly love them.

Aaron Boyd
Aaron Boyd

Hello, I’m Aaron Boyd, the proud owner and author behind Aqua Movement. I hope my article was able to answer your questions. If you want to learn more about me, click the home icon above.

Aqua Movement