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4 Best Betta Fish Tank Heaters for 1, 5 & 10+ Gallon Tanks – 2024 Reviews & Top Picks

Brooke Billingsley

By Brooke Billingsley

betta fish swimming near the substrate in the aquarium

Betta fish are tropical fish that require tank heaters to maintain an appropriate and stable water temperature. Room temperature water is rarely warm enough or stable enough to meet their needs. Choosing the right heater for your Betta’s tank is important to ensure the temperature stays at a safe, comfortable level for your Betta fish.

Regardless of the size of the tank your Betta lives in, there’s a perfect heater to meet your needs. A heater that’s too powerful can result in the death of your fish, but a heater that’s too weak can result in illness, so choosing the right heater will help keep your Betta safe. Here are reviews of the best of the best heaters for your Betta’s tank, no matter the size.

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A Quick Look at Our Favorites in 2024

Rating Image Product Details
Best for 10-Gallon Tanks
Winner
Fluval Glass Aquarium Heater Fluval Glass Aquarium Heater
  • Shock-resistant casing
  • Heats tanks up to 15 gallons
  • Temperature range of 18˚
  • Best for 5-Gallon Tanks
    Second place
    Cobalt Aquatics Aquarium Heater Cobalt Aquatics Aquarium Heater
  • Shatterproof case
  • Built-in thermal protection circuit
  • Suction cup attachments included
  • Best for 1-Gallon Tanks
    Third place
    Marina Betta Submersible Aquarium Heater Marina Betta Submersible Aquarium Heater
  • Durable polymer case
  • Fully submersible
  • Automatically restarts
  • Best for Tanks Over 10 Gallons
    Eheim Jager Thermocontrol Aquarium Heater Eheim Jager Thermocontrol Aquarium Heater
  • Accurate within 0.9˚
  • Dry run shut-off mode
  • Can heat tanks up to 264 gallons
  • The 4 Best Betta Fish Tank Heaters Are:

    1. Fluval Submersible Glass Aquarium Heater 50-Watt – Best for 10-Gallon Tank

    6Fluval Submersible Glass Aquarium Heater

    Tank Size Up to 15 gallons
    Size of Heater 1”L x 1”W x 11”H
    Temperature Range 68–86˚F
    Adjustable Temperature 68–86˚F
    Check Price on Chewy

    The Fluval Submersible Glass Aquarium Heater is the top pick for a 10-gallon Betta tank. This heater can heat tanks up to 15 gallons and is accurate within 1 degree. It is encased in shock-resistant borosilicate glass, reducing the risk of cracking, even if bumped. It attaches to the inside of the tank via suction cups.

    You have an adjustable temperature range of 18 degrees, allowing you to set it to the perfect temperature for your Betta fish. It’s made with a unique reflective casing that helps camouflage the heater within your tank, making it barely noticeable.

    This heater is quite tall at 11 inches, which may be too tall for some 10-gallon tanks. There is a fill line mark on the heater itself and the water must at least hit this level to ensure the heater does not break.

    Pros
    • Heats tanks up to 15 gallons
    • Temperature range of 18 degrees
    • Accurate within 1 degree
    • Shock-resistant casing
    • Suction cup attachments included
    • Reflective casing helps camouflage the heater
    Cons
    • May be too tall for some 10-gallon tanks
    • Must fill water at least to fill the line to prevent breaking

    2. Cobalt Aquatics Electronic Neo-Therm Submersible Heater – Best for 5-Gallon Tank

    Cobalt Aquatics Electronic

    Tank Size Up to 6 gallons
    Size of Heater 2”L x1”W x6.5”H
    Temperature Range 66–96˚F
    Adjustable Temperature Yes

    The best heater for a 5-gallon Betta tank is the Cobalt Aquatics Electronic Neo-Therm Submersible Aquarium Heater. This compact heater can heat tanks up to 6 gallons and has an adjustable temperature range of 30 degrees. It includes a one-touch setup and has a shatterproof case, preventing breakage if bumped. It attaches to the inside of the tank via suction cups.

    This thermometer is accurate within 0.5 degrees, making it a great pick to keep your Betta fish safe. It also sets itself back to the previously set temperature after turning back on after a power outage. It features an LED display that shows you the set temperature and the current tank temperature. It also has a built-in thermal protection circuit that causes the heater to shut itself down if it senses itself beginning to overheat.

    Although slim, this heater is black and noticeable, especially in a small tank. The bottom of the heater should always be submerged to prevent the heater from breaking.

    Pros
    • Heats tanks up to 6 gallons
    • Temperature range of 30 degrees
    • Accurate within 1 degree
    • Shatterproof case
    • Suction cup attachments included
    • Resets itself to previous temperature after power outage
    • LED display shows set and current temperatures
    • Built-in thermal protection circuit
    Cons
    • Noticeable in a small tank
    • Bottom must be submerged at all times

    3. Marina Betta Submersible Aquarium Heater – Best for 1-Gallon Betta Tank

    Marina Betta Submersible Aquarium Heater

    Tank Size Up to 1.5 gallons
    Size of Heater 1”L x 5.3”W x 1.7”H
    Temperature Range 78˚
    Adjustable Temperature No

    The best heater for your 1-gallon Betta tank is the Marina Betta Submersible Aquarium Heater, which is intended to heat tanks between 0.5–1.5 gallons. It is preset to approximately 78 degrees F to maintain your Betta’s tank at the perfect temperature. It’s encased in durable polymer to prevent breaking and uses suction cups to attach to the tank.

    This heater is fully submersible, so you can put it just about anywhere in your small Betta tank. After a power outage, it will automatically turn itself back on and begin warming to the pre-set temperature.

    Since this heater has a pre-set temperature you cannot adjust, it’s a good idea to invest in a thermometer to ensure the water temperature is staying within a safe range. It’s encased in a black casing, making it noticeable, especially in a small tank.

    Pros
    • Heats tanks up to 1.5 gallons
    • Pre-set to 78 degrees for Betta fish
    • Durable polymer case
    • Includes suction cup to attach to tank
    • Fully submersible so can be put anywhere in the tank
    • Automatically restarts after power outage
    Cons
    • Temperature cannot be adjusted
    • Thermometer will need to be purchased separately
    • Noticeable in a small tank

    Related Read: Top 5 Best Fish For 1 Gallon Tank (With Pictures)


    4. Eheim Jager Thermocontrol Aquarium Heater – Best for Tanks Over 10 Gallons

    Eheim Jager Thermostat Aquarium Heater

    Tank Size 15–264 gallons depending on wattage
    Size of Heater 4”L x 1.4”W x 10.3”H (75-watt)
    Temperature Range 68–90˚F
    Adjustable Temperature Yes

    The Eheim Jager Thermocontrol Aquarium Heater is the best pick for tanks over 10 gallons. This heater is available in seven sizes up to 300 watts, which means this heater can heat tanks up to 264 gallons. For a large Betta tank, you’ll likely want the 75-watt model, which heats tanks from 15–26 gallons.

    It’s adjustable from 68–90 degrees F and is accurate within 0.9 degrees and uses double suction cups to attach to the tank. This heater is encased in special lab glass that helps keep the temperature levels in the tank stable. It includes a dry run shut-off, so if the water level gets too low, the heater will shut itself off before the glass breaks.

    The casing is not reflective, so the heater may be noticeable in your tank. It also may be too tall in shorter tanks, so you may have to install it at an angle, making it more noticeable.

    Pros
    • Can heat tanks up to 264 gallons
    • Temperature range of 22 degrees
    • Accurate within 0.9 degrees
    • Includes double suction cups
    • Case is made of special glass to help stabilize temperature
    • Dry run shut-off mode
    Cons
    • May be noticeable in your aquarium
    • May be too tall for smaller aquariums

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    Buyer’s Guide: Choosing the Best Betta Fish Tank Heaters

    Why Does a Heater Matter in Your Betta’s Tank?

    Betta fish are tropical fish that require warm water. They can live in temperatures from 72–82 degrees F but they truly thrive in temperatures from 78–80 degrees F. One of the most important aspects of the temperature in your Betta’s tank isn’t just the temperature itself, but it’s the stability of the temperature. If the temperature is always fluctuating within a 10˚ range, then your Betta will be stressed and become susceptible to illness. Rapid fluctuations in temperature can even lead to temperature shock, which can cause death. Choosing a functional and reliable heater will help you ensure your Betta fish tank stays at a stable and safe temperature.

    Choosing the Right Heater for Your Betta’s Tank

    Size

    Choose a heater that is appropriate for the size of your Betta’s tank. Choosing a heater that is too high wattage for the needs of the size of your tank can result in rapid temperature fluctuations and overheating, which can kill your Betta fish. If you choose a heater that is too low wattage, then you’ll end up with the opposite problem. Bettas that are kept in water that is too cool become susceptible to disease.

    aquarium-heater
    Image Credit: Flups, Shutterstock

    Tank Layout

    Keep the shape of your tank in mind when choosing a heater and determining where you should put it. If your Betta is in a tank that is 3 feet long, then putting a heater at one end of the tank may cause uneven heating of the water. You’ll want to ensure your heater is able to be in a somewhat central location of your tank to ensure the water is heated evenly throughout the tank.

    Features

    Some heaters come with features like LED displays and built-in thermometers, which can be beneficial to help you monitor your tank more closely. Some heaters are very plain and don’t include special features, with some not even allowing for temperature adjustments. Choosing what types of features you’re interested in can help guide you in selecting a heater.

    Conclusion

    Regardless of the size of your Betta’s tank, there’s a heater to keep your Betta fish safe and comfortable. For 1-gallon tanks, the best pick is the Marina Betta Submersible Aquarium Heater, since it is intended for tanks 1.5 gallons and smaller. For a 5-gallon tank, the Cobalt Aquatics Electronic Neo-Therm Submersible Aquarium Heater is the best option available, and for a 10-gallon tank, look no further than the Fluval Submersible Glass Aquarium Heater 50-Watt.

    Using these reviews, you can start your search for the perfect heater for your Betta’s tank. It doesn’t have to be an overly complicated task to find the right heater, but it is important to choose a heater with high functionality and safety features that will ensure proper water heating and safety for your Betta fish.

    See also:


    Featured Image Credit: Andrej Jakubik, Shutterstock

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