Best Heaters For 5 Gallon Betta Tanks

Last Updated on 2023-10-18

If you’ve bought a betta tank chances are it hasn’t come with a heater. Most aquarium kits don’t add a heater because some fish don’t need them. However, if you have a betta, then a heater is a must. (In fact, you can read this whole article on the reasons you need a heater for your betta.) In this article, you’re going to find out specifically what are the best heaters for 5-gallon betta tanks.

Key Takeaways:

  • The article covers the best heaters for 5-gallon betta tanks.
  • It recommends 50-watt heaters for better heating in 5-gallon tanks.
  • Top choices include the Aqueon Pro Submersible 50W Heater for its adjustable settings and durability.
  • The Cobalt Aquatics Neo-Therm Heater offers a long lifespan but limited 2-degree adjustments.
  • The Eheim Jager Aquarium Thermostat Heater provides precise control and shatterproof glass.
  • The Freesea 50W Aquarium Heater has a wide temperature range and external temperature adjustment.
  • The Tetra HT Submersible Aquarium Heater is a budget option with reliability concerns.
  • Submersible heaters are ideal for 5-gallon tanks, and maintaining a 78°F temperature is crucial for betta health.

Best Heaters At A Glance

Best Heaters For 5 Gallon Betta Tanks

All the heaters in this article are going to be 50 watts. 50-watt heaters are usually used to heat tanks between 3-10 gallons. While you can use a 25-watt heater for your betta tank they’re normally not as reliable. With that being said here are 5 of the best heaters for a 5 gallon betta tank.

Aqueon Pro Submersible 50W HeaterBest Heaters For 5 Gallon Betta Tanks

The Aqueon Pro Submersible Heater is a bargain for the price that it is, and the best heater you can get for your betta tank. It comes with an adjustable heat setting which ranges between 68-88°F which situates a bettas ideal temp of 78°F right in the middle. 

It’s also shatterproof and extremely durable. If you’re clumsy like me you won’t have to worry about dropping it when cleaning your tank out.

One feature I love about this is that it always has an LED light showing you what the heater is doing. If it’s red it means your tank is still heating up and when it’s green it means it’s at the temperature you set. Once it’s at the temperature you’ve set it will automatically turn off, so you never need to worry about your tank overheating.

Aqueon Submersible Aquarium Heater, 50 Watts, Up to 20 Gallons
  • Fully submersible, auto shut-off when overheats, resets when cools down
  • Electronic thermostat stops heating once set temperature is reached
  • Precise temperature setting adjustable to 1° F (68-88° F)


  • The heater is fully submersible. Submersible heaters warm your tank a lot better than heaters that are only partly submersible because they distribute warmth more evenly.
  • The heater will automatically detect when your aquarium is the right temperature and turn off.
  • You can always see when it’s heating the tank and when your tank is at its optimal temperature.


  • The biggest downside of this heater is the suction cups are initially quite hard to stick to the side of your aquarium.
  • It takes a while to initially heat your tank up. Make sure you’ve got your aquarium to the right temperature before you add your betta.

Cobalt Aquatics Neo-Therm Aquarium Heater

Best Heaters For 5 Gallon Betta TanksThe Cobalt Aquatics Neo-Therm Heater is an amazing heater and would have made the top of the list if it wasn’t for the price. When looking at the best heater for a 5 gallon betta tank it’s important to balance price with quality. And the price is where this aquarium heater falls short.

Or you could see this heater as a solid investment.

One of the biggest perks this heater has is its long life. When you buy this heater you know it’s going to last for years. And a lot of people say that if something does go wrong Cobalt are quick to resolve the issue. Which is exactly what you need when your heater breaks.

Another great benefit of this heater is how discreet it is. The thin profile combined with how small it is makes it barely noticeable in your tank.

And lastly it’s easy to set up and it allows you to see the current temperature of the tank as well as the temperature you’ve set it too.

The biggest flaw of this heater is that you can only change it in 2-degree increments. However, 78°F (the ideal temperature for bettas) is on the thermostat, so this isn’t a huge issue for bettas.

Cobalt Aquatics Neo-Glass Aquarium Heater, 50W (up to 12 gal) | Fully Submersible | Ideal for Freshwater and Saltwater Aquariums
  • Advanced Thermostat Technology: Equipped with state-of-the-art electronic thermostat technology, ensuring precise temperature control for your aquarium environment.
  • Easy Temperature Setting and Monitoring: Features an easy-to-use push-button thermostat and a clear digital temperature display for hassle-free adjustments and monitoring.
  • Fully Submersible Design: Designed to be completely submersible, offering versatile placement within freshwater or saltwater aquariums up to 12 gallons.
  • Reliable Heating Solution: Provides consistent and efficient heating, maintaining optimal conditions for aquatic life with minimal energy consumption.
  • Durable and Safe: Constructed with high-quality glass, this heater is built to last and includes safety features to prevent overheating and ensure safe operation in your aquarium.


  • Long life – If you have this heater it’s going to last you years.
  • The heater is discreet and small. It’s design and size make it blend into an aquarium


  • You can only adjust the heater by increments of 2°F. This isn’t a problem for bettas but could be for other fish.
  • It’s more on the pricey side. However, it’s definitely worth the investment if you have the money.
Best Heaters For 5 Gallon Betta Tanks

Eheim Jager Aquarium Thermostat Heater

Best Heaters For 5 Gallon Betta TanksAnother great heater for 5-gallon tanks is the Eheim Jager Aquarium Thermostat Heater. It’s a heater that isn’t going to set you back too much and has a LOT of great features.

One of the features that I really like about this aquarium heater is the light that lets you know if it’s heating your tank or not. This makes monitoring your aquarium a lot easier.

And if you were concerned about the lack of control in the Cobalt heater then this one more than makes up for it. In fact, you can set the temperature in 0.5°C (about 0.4°F) increments, which is a lot more finely tuned.

The glass is also shatterproof. And while shatterproof glass isn’t completely necessary, it’s still better to have it. The chances of glass shattering in a tank are slim, but still there. So why not just cut that risk altogether. And the glass that surrounds the heater also causes a larger radiation space. Meaning heat will be distributed more evenly.

However, one downside to this heater is the way that it looks. It’s very large and will take up a lot of space in any tank smaller than 5 gallons. And on the subject of the way it looks the blue ring and the other colors draws a lot of attention to it, making your tank look a lot more unnatural.

EHEIM Jager Aquarium Thermostat Heater 50W, Black
  • Fully submersible
  • Thermo safey control protects against running dry
  • Will automatically turn off when water level dips too low
  • TruTemp dial recalibrates the heater for precise temperature regulation
  • Made of shock resistant and shatter proof glass for fresh or marine water


  • The temperature settings are extremely accurate and there are very tight controls stopping water fluctuations occurring.
  • Once you’ve set this heater you can just forget about it.


  • All the different colors draw attention away from your betta and the visual appeal of your tank.
  • The heater is very long and may not fit in tanks smaller than 5 gallons.

Freesea 50W Aquarium Heater

Best Heaters For 5 Gallon Betta TanksThe Freesea 50W Aquarium Heater another great heater with a lot of cool features. And if you like the look of it then you should definitely add it to your betta tank.

If you’re looking for a heater with a wide variety of temperature settings then this is going to be the ideal choice. You can set the temperature from anywhere between 59-94°F, which is an extremely wide range. If you don’t want to use this heater in your bettas tank then it also makes a great quarantine tank heater! (If you’re interested you can follow the link here to learn everything you need to know about quarantine tanks.)

Another great feature of this heater is that you don’t have to change the temperature on the heater itself. The dial you need to use is on the cord outside. This is great for two reasons. First of all, there’s less risk of you contaminating your fish tank and secondly, you don’t have to get tank water all over your hands.

And this is another heater that is set and forget. Once you’ve set your ideal temperature you can just leave the heater to do its thing.

The only downside is that it doesn’t look too great and the big red number on the heater is kind of distracting. Also if you’re using this heater you have to make sure you NEVER take it out of the tank when it’s still on or it could overheat and break.

The other heaters on this tank aren’t as fragile as this one and that’s really what causes it to end up near the bottom of the list.

FREESEA Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon
  • FREESEA Aquarium Heater: 50w betta fish heater, voltage: 110~120V, is suitable for use in 1-10 gal betta fish turtle tanks and aquariums. The power cord is 5ft, long enough for indoor use
  • Double Safety Protection: When the top part of the turtle tank heater is out of water it will auto shut off. When the actual water temperature is higher than 94°F, it will auto activate the overheating protection and stop heating


  • You can adjust the temperature from outside the tank.
  • It’s extremely accurate and it’s going to keep your tank at a consistent temperature.
  • It’s doesn’t take up much space in the tank.


  • You can never take the heater out of the tank when it’s on. This could make it overheat and break.
  • The large red LED temperature reading can be distracting.
  • The cord isn’t as long as other heaters.

Tetra HT Submersible Aquarium Heater 

Best Heaters For 5 Gallon Betta TanksI wouldn’t recommend this heater unless you can’t afford any of the other heaters on this list. And even if you do buy this heater you should consider it a temporary heater until you can get something better.

The heater does have a light system that helps you determine when your aquarium is being heated and when it’s at its ideal temperature. When it’s red it’s still heating and when it’s green it’s ideal.

It’s also quite easily concealable. Because of its size, you can lay it down horizontally at the bottom of your tank or hide it behind ornaments.

The biggest problem with this heater is that a lot of people complain that it breaks relatively quickly. So that’s why I’d recommend only buying it as a temporary heater until you can get something better.

And the only other problem is that it only comes with one suction cup. This can make it hard to keep it stuck in one place. If the cord gets bumped or pulled it causes the heater to shift.

Tetra HT Submersible Aquarium Heater With Electronic Thermostat, 50-Watt, 2-10 Gallon
  • All Tetra HT heaters have indicator lights to let you know when the heater is on. It will be red when heating and green when the proper temperature has been reached..All Tetra HT Heaters will shut off if an electrical short is detected for your safety.
  • The HT10 uses a built in electronic theromstat to automatically maintain water at 78° F which is ideal for most tropical fish. No adjustment is requried.
  • Ideal for aquariums between 2 to 10 gallons with hoods or glass canopies


  • One of the most inexpensive heaters you can get.
  • Small size means it’s very discreet.


  • They’ve been known to break easily, which could leave your fish stranded without a heater.
  • Only one suction cup means that oftentimes the heater gets knocked into a different position.

Why Should You Use a 50 Watt Heater?

If your tank is 5 gallons then it’s entirely possible to use a smaller heater such as 25 watts. And there’s nothing wrong with that. However, a 50-watt heater is going to be able to heat a tank a lot better and a lot quicker than a 25-watt heater. For example, if the temperature in your room drops suddenly, what heater do you think will be able to keep up with the drop better?

As well as this having a 50-watt heater will also allow you to migrate it to a bigger tank. While a 5-gallon tank is great for a betta on its own when you want to start adding something bigger you’re going to want to move to a bigger tank. This way you can take your heater as well. (If you want to know more about bigger aquariums then you should check out a review of the four best 10-gallon tanks.)

Why Should You Use A Submersible Heater?

If you don’t know already there are many different types of heaters you can use. There are substrate heaters which go underneath your substrate, hanging heaters which are only partially submerged, in-line heaters which suck in aquarium water, heat it and then return it to the tank, and in-filter heaters which are heaters stored in your filter.

The reason that they weren’t mentioned in this article is that they’re not as efficient for a 5 gallon tank as submersible heaters. If you’ve got a 5 gallon tank you don’t need an overly expensive heater. They’re only needed in bigger aquariums. In fact, some of them probably wouldn’t even be able to fit in a 5 gallon tank, or would take up far too much space!

(Still looking for an aquarium? Here are the best 5 gallon aquariums!)

A Recap On The Best Heaters For A 5 Gallon Betta Tank

As you can see, there are so many great heaters for you to choose from. If you’re just starting out the Aqueon Pro Submersible Heater is going to bring you the balance between a great heater and a great price. However, if you want to spend that little bit more to get an amazing heater then you should pick some of the more expensive heaters!

Either way, the most important thing you can do is buy a heater that can keep your tank at 78°F consistently so that your betta can be happy and warm!

If you have any more questions you can leave them in the comments otherwise here are some more great articles for you to check out:

  • Do Betta Fish Need A Heater –  Find out why it’s so important for your betta to have a heater and what’s going to happen if your betta is in water that’s too hot or cold. As well as this, you’ll also learn what to do in an emergency situation where your heater has broken.
  • Betta Fish Water Conditions – If you’re not sure what the ideal water conditions are for your betta then you need to check out this article. Learn the different types of water you can use, as well as which water is best.
  • Marineland ML90609 Portrait Aquarium Review – If you’re looking for an aquarium for your 50 watt heater then look no further. This aquarium is unlike any other and when you read this article you’ll see why!
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