Do Betta Fish Need a Heater? Helpful Guide

In the aquarium world, the Betta fish is the most popular tropical ornamental fish. In Malaysia, Cambodia, and Thailand, betta fish are widely distributed in the Southeast Asian region. It is widely believed that Betta fish make excellent first pets, despite their popularity among freshwater fish. As a result, I’d like to ask: Does a heater benefit Betta fish, and does their environment and food need to be considered? For bettas, the ideal temperature range is 72 to 82 degrees Fahrenheit. Any temperature below or above this range can make your fish too inactive or slow.

As compared to other fish species, betta fish require smaller tanks. The fish are typically kept in bowls with filters by aquarists. Many people, however, do not realize how sensitive betta fish are to water quality. When it comes to betta fish, water temperature is important to consider so that negative impacts can be prevented.

Do Betta fish need heaters? The temperature of the aquarium water must be kept above certain levels in tropical climates to keep betta fish healthy. Moreover, I’ll tell you what the ideal water temperature is for betta fish.

What Do Bettas Fish Need in their Tank?

Bettas need a heater, that’s all. Warm water at a constant temperature is necessary for them to thrive. You can only do this by using a heater inside the tank.

Bettas require a filter, a heater, and an aquarium with at least 3 gallons (11 liters). Make sure their new house is ready at least one day before they arrive. A good aquarium position is a location with low traffic, close to a power supply, and out of the direct sun and wind. Per gallon, water weighs around 8 pounds.

Does A Betta Need A Heater To Survive?

Bettas can survive with or without a heater depending on a variety of factors. If the temperature in your room is above 78°F, your betta will likely live a long time. In cold weather or if your betta is already ill, he may become gravely ill within a few days. Temperature, betta’s age, health, how quickly the water temperature is lowering, and a multitude of other factors should be considered.

Betta Heater Buying Guide

There are many aquarium heater models available, and lots of “poor advice” is frequently given when choosing which heater to use for betta tanks. Buying a heater can be a challenging task, so I will give you some information that will help you:

1. Choose a Heater With a Thermostat

A heater without a thermostat makes it very easy to overheat your tanks. Particularly if you have a tiny tank, as many people do. Heaters are turned off when a preset temperature is reached. In this way, your betta won’t be effectively cooked if the room temperature is high and the heater is continuously on.

Fortunately, most models come with thermostats, but it is still a good idea to verify this before purchasing.

2. Get a fully Submersible Heater

Submersible heaters work better and are more efficient. It’s that simple. In addition, it could cause problems if a heater is mistakenly dropped totally into the tank.

3. Choose Glass Over Plastic

I prefer glass tubes over plastic and other materials. In my opinion, they look so much better than plastic, which stains and changes color very quickly. Additionally, heat transfer is more efficient.

Other Important Heater Facts

You should consider the following when choosing a heater for your Betta tank:

  1. 3-5 watts are recommended per gallon of water.
  2. In order to avoid contact with gravel, filter, or ornaments, it must fit firmly inside the tank.
  3. The filter should be able to circulate heat and water well if you position it in a corner.
  4. If you don’t use a fully submersible heater, make sure it has an upper screw to secure it to the tank, not just suction cups. As bettas swim, they often remove the suction cups and heaters in their path.
  5. As a result, the entire item will sink below the surface of the water. Most models have a shutdown switch, but I don’t recommend testing it.

What’s The Ideal Temperature For Bettas?

Betta fish require water that is between 76 and 81 degrees Fahrenheit. Although they can survive at temperatures as low as 72 degrees Fahrenheit.  They may even die if temperatures fall below 69 degrees for any duration.

  • Due to a low tank temperature and a weak immune system, they may suffer from:
  • Often, fur coat syndrome results in death due to a bacterial infection.
  • A dormant white spot infection can suddenly come back.
  • Infections of the mouth and fins

Furthermore, they can survive in water up to 82 degrees Fahrenheit. Long-term use is not advised due to the fact that you are slowly frying fish. Therefore, always maintain 74-78 degrees in your betta’s water.

What Happens When Bettas Get Too Cold?

Bettas are tropical fish, which means they cannot handle extreme cold like cold-water fish. However, betta can’t withstand much lower temperatures because of the internal controls they lack. All fish have the same body temperature as the water they live in.

Tropical fish regulate their body temperatures similarly to cold-blooded reptiles. Furthermore, you will find out why too much cold can cause bettas to die within minutes to hours.

You might have a cold betta if:

  • Taking it easy while swimming
  • Will sit close to the heater or any area with a warmer water current
  • A dull appearance and loss of color
  • A rise in illness and infection

What Will Happen If A Betta Gets Too Hot?

A betta will begin to overheat progressively over 85°F if it gets too hot.

The first symptom you’ll notice is that your fish is swimming wildly. The only way for fish to maintain a constant temperature is to be in contact with it. The increased heat will give them extra energy. Your fish will suffer greatly from stress if you do this, which will damage their immune system.

A Regulated Temperature is the Best

It is essential to keep temperatures steady and within the ideal range for Bettas.

Temperature fluctuations during the day or season are normal and will not harm you. It may be more harmful to have a steady temperature just outside the ideal range than to have a temperature change of 8 degrees. I also recommend larger betta tanks for this reason. As water volume increases, the temperature will change less and less.

To maintain 78 degrees Fahrenheit in my betta tanks, I have to use a thermostatic heater.

Water Temperature Stability and Tank Size

Unheated water fluctuates a few degrees with volume regardless of ambient temperature. For instance, if the air temperature suddenly drops from 75 degrees to 70, the water temperature in your aquarium won’t change as quickly. It might take a while.

Additionally, greater temperature differences require longer times to reach room temperature. The larger the aquarium, the more stable the water temperature is, as well as less waste accumulation.

Bettas cannot survive in a small bowl because the temperature changes constantly with the surrounding room.

Bettas are quite sensitive to frequent variations of +/- 5 degrees, even if a change of one or two degrees does not bother you or them. A minimum of three gallons is recommended for betta aquariums, as I have mentioned before. Better water quality and more consistent temperatures benefit them.

In a one-gallon bowl, it may take 15 minutes for the water to reach room temperature, but in a three-gallon aquarium, it may take 45 minutes to an hour. Slower changes are far better for bettas if they have to deal with them.

How To Heat A Betta Fish Tank In An Emergency

The loss of steady filtration, as well as the failure of the tank heater, cools down the water and makes your Bettas miserable.

You can maintain a safe temperature by following these last-minute tips. The use of these techniques may not completely maintain stability, but they can keep your fish alive and reduce illness risk until proper heating can be restored.

  1. Make your home warmer. This might be useful if you have a small tank or know it won’t be long until your tank can be heated again. If you heat your home, the room temperature won’t reduce the water temperature.
  2. Move your tank away from any windows and closer to the middle of your home. Your home is often cooler near windows because windows let heat escape.
  3. If the weather is pleasant and sunny outside, you might consider doing the opposite. If you leave your tank in the sun, the water will warm up. Be careful not to overheat it.
  4. Take some hot water and put it in a bag. It should be enough to fill 10% of the tank’s volume. It should be warm, but not boiling. After removing 10% of the water from your aquarium, place the bag in it. After that, let the bag float on top of your tank.
  5. You can cover the open top of your tank with a cloth to help retain heat. In addition, a cover can trap heat inside. You can keep your tank warm by covering it with a towel since the heat rises.
  6. If you want to keep the heat in, you can wrap towels around your tank. Changing lights might frighten your betta a little, but a drop in water temperature will be more threatening.
  7. Make use of any additional heating appliances you may have. For example, you could place a bulb near your aquarium and direct its light there, or you might use a hairdryer to dry it. You may be able to find something more permanent if you use these temporary fixes.
  8. A great alternative to a broken heater is to wrap your tank in an electric blanket. Watch your tank’s temperature closely.
  9. You should place candles all around your aquarium. Tea lights are the most effective candles. You can keep your tank’s water warm by burning enough fuel around the flames.

How to Operate your Heater Safely

Keep aquarium heaters safe for you and the fish in your tank by following these guidelines:

  • Ensure very large tanks have a thermometer, or even several, to monitor temperature variations.
  • Especially before bed and early in the morning, check the temperature several times a day. There are times when heaters malfunction, so you should identify them immediately.
  • After you turn it off, let the heater sit in the water for an hour before you plug it in, so that the glass is able to reach equilibrium with the water temperature.
  • Understand how your heater’s thermostat works. You can set some by temperature, others by simply “more” or “less”. Whenever possible, do not adjust the setting to more than 1.4 turns at a time. A heater may generate a killer temperature if an adjustment is too high and you forget to monitor it until stable.
  • Always pay attention to the waterline indication when using a semi-submersible heater. A high water level can cause an electric shock, while a low water level can cause an overheated heating tube.


A heater is typically required for Bettas to survive. A reliable heater will keep your betta tank’s water temperature consistent, preventing big, abrupt temperature fluctuations that stress your fish. Your betta can be protected from harm with heaters that have thermal fuses and automatic shut-offs. If you live in a warm climate or heat your home all year round, you might not need a heater.

Your betta’s tank’s water temperature still needs to be carefully monitored, as rapid temperature swings are still possible. It is essential to have a reliable thermometer in this situation.

Your choice to use a heater in your betta aquarium is ultimately up to you. In case of doubt, take it on the side of caution and use a heater.

You should also consult your local pet store if you have any doubts about whether your betta requires a heater. They’ll be happy to help you determine what’s best for your betta fish. I appreciate you taking the time to read this.

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