9 Best Heater For 3 Gallon Betta Tank 2021 Consumer Reviews

Best Heater For 3 Gallon Betta Tank

Looking for the best heater for your 3 Gallon Betta Tank? Then don’t worry as we’ve scoured the internet and found our 9 top items for you.

Among the most critical pieces of equipment for keeping your betta fish healthy is a tank warmer. Bettas are accustomed to tropical waters, which are often hotter than your home’s indoor temperature.

Because the temperature in your house varies depending on how warm or cold it is outside, it is not as stable as the temperature in betta’s natural surroundings. A tank heater can compensate for these variances by maintaining a warm, consistent temperature in your aquarium.

However, picking the correct heater for your betta fish can be difficult, particularly with so many inexpensive heaters on the market that don’t perform as well as they claim. Today, we’ll go through the qualities to look for in a betta fish heater, as well as a review of five of the finest heaters for your betta.

The lack of space in tiny tanks is one of the most common concerns. There isn’t much place for anything else after you’ve set up your decorations, such as gravel, plants, and pebbles – especially not a heater. And, before you ask, no, you will not be able to avoid purchasing a heater.

Rapidly increasing and decreasing temperatures, on the other hand, generate stress in your fish, which can quickly lead to death. In addition, temperatures in a small tank vary considerably more quickly than in a big one. Furthermore, tropical fish such as betta require warm water to live. Because of this, a heater is required in your little tank, no matter how crowded it is.


We totally value the time of each consumer who is looking to purchase a new heater so if you don’t want to go through the whole article and you are in hurry then don’t worry as we have provided these 3 top picks from the entire list which you can purchase blindly.

Small aquarium heaters come in a variety of shapes and sizes:

First, let’s go through the two sorts of heaters available to you.

Preset Aquarium Heaters:

Preset heaters are designed to attain a specified temperature, usually 78 degrees Fahrenheit (26 degrees Celsius). When this degree is achieved, the heater turns off automatically and does not switch on again until the temperature falls below it. The bulk of the preset heaters developed exclusively for tiny tanks, on the other hand, function in a unique way: they are “always on” and never turn off. Are there any fishes in your aquarium that prefer cooler or warmer water? Good luck! You can’t do anything about it; you’re stuck with your heater.

It’s not difficult to uncover horror stories about preset heaters harming fish. Heaters that are always on do not adjust the temperature. Using these heaters will raise the temperature of your tank if the temperature of your room rises, such as on a hot summer day. Using an aquarium temperature controller, however, you can get around this.

This ingenious gadget switches off your heater when the water becomes too hot, then switches it back on when the water cools down, keeping your fish safe. The size of preset heaters is the most significant benefit. Manufacturers have been able to produce some incredibly thin and compact aquarium heaters without the need of a thermostat.

Adjustable Aquariums Heaters:

These aquarium heaters allow you to set a temperature within a specific range, usually between 66 and 96 degrees Fahrenheit (19 and 36 degrees Celsius). When this temperature is achieved, the heater turns off and does not turn back on until the temperature falls below this threshold.

While adjustable heaters are often bigger than preset heaters, they offer the advantage of letting you to alter the water temperature based on marine life. To prevent your fish from cooking or freezing, set the thermostat to make the water hotter in the winter and colder in the summer.  

9 Best Heater For 3 Gallon Betta Tank (Comparison Table)






Marineland Precision Heater for Saltwater 


Eheim Jager Aquarium Thermostat Heater


Fluval E 50-Watt Electronic Heater


ViaAqua 200-Watt Quartz Glass Submersible Heater 


EHEIM Jager Aquarium Thermostat Heater 


Finnex Hang-On Electronic Controller Aquarium Heater


ViaAqua Quartz Glass Submersible Heater 


Fluval M50 Submersible Heater


Marineland Precision Heater for Saltwater 

9 Best Heater For 3 Gallon Betta Tank (Buying Guide)

1. Marineland Precision Heater for Saltwater

Category: Best inexpensive heater for 50 Watts for heater.

The Precision Submersible Heater allows you to precisely adjust the temperature of your aquarium. The heater features an adjustable temperature dial, a large temperature display, and a powerful water heater to keep your aquarium water at the perfect temperature for your freshwater or saltwater fish.

  • Features:  This Marineland Precision Heater for Saltwater or Freshwater Aquariums has following features:
  • This 50-watt heater is suitable for aquariums with a capacity of up to 12 gallons. With each click of the temperature dial, you may raise or lower the temperature by one degree.
  • A mica core is encircled by a mesh heating element in this innovative heating element, resulting in greater heat transmission and increased durability. 
  • Direction: Suction cups (provided) are attached to the double suction mounting bracket. Slide the bracket over the heater to the required location. Place the heater in the aquarium by placing the suction ends on the tank’s wall. You can observe the situational factors from three different angles thanks to the three-position viewing window; simply crank the heater till it latches into the ideal view configuration.
  • Required temperature: Most tropical fish like water temperatures of 78°F to 81°F. Note: Using a tank cover to avoid water temperature fluctuations from causing heat loss is suggested. Both can degrade the heater’s function, putting the fish in danger.
  • Large temperature
  • Easy to install
  • Great materials
  • Less heat loss
  • Three viewing position
  • Switches off automatically

2. Eheim Jager Aquarium Thermostat Heater

Category: best thermostat heater submersible for betta fish tank.

The ability to recalibrate Jager heaters is one of the reasons they have a reputation for being the most precise heaters available. The factory setting should be quite similar, but you may need to recalibrate the heater if you changed either the red arrow or the blue dial before following instructions.

  • Features: This Eheim Jager TruTemp Submersible Heater has following features:
  • The ‘running-dry’ safeguard is enabled by this safety feature. When you withdraw the heater from the water, it will switch off and then turn back on.
  • This handy feature removes guesswork and allows the user to test the heater’s functionality without getting their hands wet.
  • TruTemp heaters are pollution-free, chemical and biologically resistant, and capable of withstanding high temperature changes. Their glass coats also increase the heating surface area and guarantee that heat is distributed evenly.
  • Direction: A mounting bracket and suction cups are included with each Jäger TruTemp Heater for secure and flexible placement inside your tank system. Finally, most applications may be accommodated with an extra long power cord. 
  • Required Temperature: The temperature may be changed exactly between 18° and 34° C (65° and 93° F). The user may recalibrate the heater for an accurate temperature measurement by using the TruTemp dial with readjustment ring. The temperature control precision is +/- 0.5° C.
  • Easy to install
  • Does not pollute
  • Adjustable temperature
  • Easy to operate
  • Expensive

3. Fluval E 50-Watt Electronic Heater

Category: Best portable heater can be used up to 100 gallons.

Best portable heater can be used up to 100 gallons

Fluval’s tank heater is intended to make heating your aquarium simple and hassle-free. The heater has a tiny LCD monitor that shows the current temperature of the water in your aquarium.  

  • Features: This has following amazing features such as:
  •  The dual-sensor VueTech microprocessor technology in the E-Series digital heaters shows precise water temperature and graphically warns the user of any changes.
  • In addition, based on what the water temperature is under, at, or above the temperature you specified, the screen changes color from blue to green to red.
  • The heater is totally shielded against your betta coming into touch with the heating elements, as well as shockproof to avoid harm from drops or larger fish impacting it.
  • Direction: The accompanying mounting bracket may be placed almost anywhere in your tank, and the heater may be removed without removing the mounting bracket. Even better, the heater can be mounted in any orientation on the mounting bracket, allowing you to conveniently view the temperature display.
  • Required Temperature: The heater has a temperature range of 68 to 93 degrees, giving you lots of flexibility in altering the temperature for hot and cold days. Furthermore, for even more control over your tank, the temperature may be adjusted in 0.5-degree levels.
  • Up to 100 gallons
  • Easy to install
  • Displaying screen
  • LED lights
  • Expensive

4. ViaAqua 200-Watt Quartz Glass Submersible Heater

Category: best submersible heater for 3 gallon tank.

best submersible heater for 3 gallon tank

Quartz heaters by ViaAqua are a newer and better version of glass heaters. Submersible heater with a visible temperature readout made of high-quality quartz glass.

  • Features: The Quartz heaters by ViaAqua  has following features:
  • It has water proof double insulation which means it will not be affected by water. 
  •  When the heater is heating the red light is on. When the heater is not heating the red light is off.
  • Direction: The suction cups make it simple to fix your heater in the correct location. Suction cups to keep your tank in place.
  • Required Temperature: Temperature setting that can be seen for precise reading. Freshwater and saltwater are both compatible. Temperatures range from 68 to 92 degrees Fahrenheit.
  • Inexpensive
  • Visible temperature
  • Double insulated
  • Fully submersible
  • Easy installation
  • Plastic

Also Read : Best Algae Eaters For 10 Gallon Tank

5. EHEIM Jager Aquarium Thermostat Heater

Category: Best mid-ranged heater for betta fish tank.  

Best mid-ranged heater for betta fish tank

With a few significant modifications, the Jager Aquarium Thermostat Heater from EHEIM offers almost the same adaptability as the Fluval E heater. When the tank water level falls too low, the heater shuts off automatically, and a safety feature keeps the heater from drying up.

  • Features: First of all, this iJager Aquarium Thermostat Heater from EHEIM. It has following features:
  •  Because the heat dial is located on the top of the heater, it is easy to see and turn. For precision temperature control, the temperature may be altered in 0.5 degree increments at a time.
  • Bear in mind that this heater is 20 inches in length, therefore your tank will need to be curved to allow the warmer to be fully immersed. Miniature ones of this tank heater, rated at 25 watts, are available from EHEIM and are appropriate for small 5-gallon tanks.
  • Direction: Furthermore, the heater is built to be shockproof and shatter resistant. This heater may be mounted anywhere in your aquarium thanks to the accompanying mounting bracket and suction cups.
  • Required Temperature: This heater can reach temperatures as low as 65 degrees, which is great if you live in a hotter climate and the heater’s primary objective is to maintain a stable water temperature. 
  • Easy to install
  • Can be used for up to 100 gallons
  • Auto shut off
  • Expensive

6. Finnex Hang-On Electronic Controller Aquarium Heater

Category: Best hang on heater for 3 gallon tank.

Best hang on heater for 3 gallon tank

The Finnex Compact Electronic Titanium Heaters keep water temperature within +/-2oF of the chosen value, ensuring that your tank is kept at a safe, healthy, and consistent temperature. 

  • Amount of usage: This Finnex Compact Electronic Titanium Heaters should be used as directed below:
  • Because the titanium tubes resist corrosion, they are essentially indestructible in both saltwater and freshwater aquariums.
  • A LED heating indication is also included to let consumers know when the heater is on.
  • Fast heating titanium tube that is corrosion-resistant and almost indestructible. Providing aquarium life with a consistent temperature environment.
  • Installation: Due to their small size, these extremely quick heating tubes are simple to conceal. They also have a precise electronic control with a hang on hook. 
  • Required Temperature: The super heating titanium also maintains a consistent temperature for your aquarium’s inhabitants and minimises temperature swings that stress the aquarium’s inhabitants. 
  • Easy to install
  • Titanium material
  • LED heating
  • For both salt water and fresh water
  • Expensive

7. ViaAqua Quartz Glass Submersible Heater

Category: best heater for 3 gallon betta tank.

best submersible heater for three gallon tank made from high quality material

The ViaAqua aquarium heater is a rod-shaped device that keeps the contents in a moderate tank up to 80 gallons at a reasonable temperature. The heater is composed of shatter-resistant quartz glass, which can withstand pressure and a reasonably high temperature without shattering or tearing.

  • Features: This has following features:
  •  Except for the temperature knob, which should stay above the water at all times, the heater is entirely submersible in both fresh and saline water.
  • The gadget has an easy-to-read temperature scale incorporated into the main body of the heater that is visible even when submerged in water. It also contains an LED indication light that illuminates while the tank is being heated or when the water temperature has reached the desired level.
  • Direction: As there is no way to install it diagonally and keep the knob securely out of the water, this is a drawback for folks with shallow tanks. Apart from the 300 watt heater, ViaAqua offers heaters for aquarium tanks of various sizes, including 50 watts, 100 watts, and 200 watts.
  • Temperature required: The ViaAqua aquarium heater has a temperature control knob with great precision that you may use to set your favorite temperature settings. Furthermore, this heater may be readily mounted to the aquarium walls using the included suction cups, which keep it in place for the duration.
  • High-quality quartz glass
  • Fully submersible
  • Easy to read temperature scale
  • Fresh and salty water
  • Best for bigger tank.

8. Fluval M50 Submersible Heater

Category: Best portable temperature for small betta tanks.

Best portable temperature for small betta tanks

Although it lacks several of the sophisticated features of the E heater, such as the LCD temperature monitor, this totally submersible heater from Fluval is a less cost alternative to the E heater. The M-Series submersible heaters deliver outstanding performance, unrivalled dependability, and proprietary mirror technology to blend in with their environment.

  • Features: It has following features:
  • Better still, Fluval built the heater to be completely shockproof, so your betta will not come into direct touch with the heating components, even if there is some shielding from the hot core.
  • Bear in mind that, despite its little size, this heater is still 11 inches in length. That implies it can’t even fit in many of Fluval’s existing 15-gallon tanks, including the EVO Reef 13.5 or the Flex 9.5-gallon tank.
  • Installation: The heater is really simple to set up. The heater comes with a small mounting bracket that allows you to set it anywhere and remove it from the tank without having to remove the bracket.
  • Required temperature: The heater has a restricted temperature range of 66 to 86 degrees, so if your home is usually cold, you may need to upgrade to a more powerful heater. Using the lever at the top of the heater, you can simply adjust the temperature in 1-degree intervals.
  • Portable
  • Shatter resistant
  • Protected from betta
  • Inexpensive
  • Small
  • Restricted temperature

9. Marineland Precision Heater for Saltwater

Category: Best 200 watts heater for salt water and fresh water aquariums.

Best 200 watts heater for salt water and fresh water aquariums.

The Marineland brand is the world’s premier provider of cutting-edge equipment and surroundings for anyone looking to create the perfect aquatic display. For almost 40 years, the brand has been dedicated to fishkeeping success, and it is the professional option for commercial display systems and scientific research. Make your tank whatever your hobby is: freshwater or saltwater, large or little, aesthetic or science.

  • Features: This Marineland Precision Heater for Saltwater or Freshwater Aquariums comes with all the amazing features such as:
  • Temperature Turn: Turns off when the temperature goes above a pre-set level and immediately turns on before the temperature drops.
  • ADVANCED HEATING ELEMENT: A mica core is encased in a mesh heating element for improved heat transmission and durability.
  • EASY TO SEE: The temperature setting is shown by a sliding scale. The setting from a different position may be seen in the top dial view.
  • Installation: MOUNTING BRACKET: Attaches securely to glass and allows for three window locations to see the temperature display.
  • Temperature range: Choose your preferred temperature. Turn the temp choice dial on the “Click Set” thermometer until the red light on the thermometer scale reaches the proper setting. Most equatorial fish like water temperatures of 78°F to 81°F. 
  • Temperature dial.
  • Can be used up to 100 gallons
  • Protective layering
  • Easy to install
  • Expensive
  • Preset temperature

What is the ideal temperature for a Betta’s tank?

A betta fish’s optimal temperature is between 74 and 82 degrees Fahrenheit. While they may survive in colder or warmer temperatures for short durations, temperatures outside of this range can stress your betta and may reduce its longevity. In most houses, the room temperature is between 66 and 72 degrees, which is too chilly for betta fish.

That is why investing in an aquarium heater is critical. Another thing to remember is that the temperature of your water should be fairly steady. Changing the temperature between 74 and 82 degrees on a regular basis might be just as stressful for your betta as having a tank that is too hot or too cold.

How to Select a Heater?

When it comes to selecting a heater for your betta tank, there are a few factors to keep in mind:

  • Watts to Tank Size: Your heater must have enough power to heat all of the water in your tank completely and consistently. For every gallon of water, your heater should give 3 to 5 watts. If you have a 10-gallon tank, you’ll need a heater with a power output of 30 to 50 watts. Alternatively, instead of one large heater, two small heaters might be used. This is often better since you may place them on opposing sides of the tank and distribute the heat more evenly. Two 20-watt tank warmers might be used for the same 10-gallon tank.
  • Adjustability: Not all betta tank heaters are adjustable, which may come as a surprise. Many low-cost heaters, on the other hand, merely heat the water to a predetermined temperature and then turn off. Having an adjustable heater allows you a lot more freedom in terms of maintaining a constant temperature in your tank. That’s because an adjustable heater allows you to turn it up on severely chilly days and turn it down on exceptionally hot days.
  • Readability: The finest betta fish heaters include a readily accessible temperature scale. It’s easy to set your heater to the appropriate setting and identify when the water has reached the correct temperature if you can see the temperature scale. Keep in mind, though, that the temperature readout on your heater isn’t always accurate.


Despite the fact that any of these five heaters may keep your betta fish warm and healthy, the Fluval E Electronic Warmer is the finest betta fish heater available today. The heater has a temperature range of 68 to 93 degrees Fahrenheit and may be adjusted in 0.5-degree increments. Even better, the built-in LED screen displays the temperature of the water and employs a color-coding system to notify you when the water temperature is cooler or warmer than the temperature you chose. Furthermore, the Fluval E is six inches shorter than the EHEIM heater, which does not have a temperature monitor. If it’s out of your financial range, the EHEIM Jager is the second best option for me.  


For a 3 gallon fish tank, what size heater do I need?

The more watts the heater has, the more powerful it is. For example, a 20-watt heater is twice as strong as a 10-watt heater. The more watts you need to heat your aquarium, the bigger it is.

In a 3 gallon tank, can I use a 50 watt heater?

The issue with a 50w for a 3 gallon is that if it fails in a way that causes a temperature increase, the 3 gallon might soon overheat. If you still have the 10 gallon but wish to keep the fish in the 3 gallon, place the 3 gallon into the empty 10 gallon and fill it with 5 gallons of water.



  • Adams, Christopher. “Best Betta Fish Heaters (Safe & Reliable) Reviewed 2021.” Modest Fish, 23 Apr. 2021, modestfish.com/betta-fish-heater   
  • Sterling, Ian. “3 Best Small Aquarium Heaters for Tiny Tanks 1 – 10 Gallons (20+ Tested).” FishLab, 7 Apr. 2021, fishlab.com/small-aquarium-heater.

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