Best Betta Fish Heater: Safe & Reliable Heaters for Betta Tanks

Best betta fish tank heaters
Find the right betta fish tank heater for your setup

Welcome to my guide to the best betta fish tank heaters. In this guide, you will find information on what constitutes an adequate heater for your betta tank. We warn against products that are specifically branded as betta fish heaters due to their inferior quality. We discuss the different types of heaters providing circumstantial recommendations.

Over the years, I have tried dozens of heaters for my bettas and can think of a select few who I believe are the best on the market.

If you’re coming on to this page to find an appropriate and adequate heating unit for the aquarium of your betta fish, then you are in the right place. By the end of this article, you will know how to keep a betta fish warm and cozy.

If you’re here to get a quick recommendation, I have listed below the betta fish tank heater. To make a long story short, I like these because they are consistent, accurate, durable, safe, manufactured by reputable brands, and are more adequate for a small aquarium (10 gallons).

  1. Fluval E 100-Watt Electronic Heater
  2. EHEIM Jager Thermostat Heater 50W
  3. Aqueon Adjustable Pro Aquarium Heater
  4. Tetra HT Submersible Aquarium Heater

If you’d like to read all of my ramblings, as I like to call them, then keep reading.

Map of South Asia
Map of South Asia

So why do betta fish need a heater?

Bettas are native to Southeast Asia where the climate is tropical. The adequate water temperature for betta fish ranges between 25 and 28° Celsius. Unless you live in a tropical climate and don’t use air conditioning, then you probably don’t need one. It’s preferable that your aquarium’s water temperature remains within the range of 25 and 28° Celsius. If temperatures slightly fall below, your fish won’t die but it’ll become highly susceptible to deadly diseases.

Monthly Temperature ranges in Thailand
Monthly temperature ranges in Thailand

Bettas are one of the most popular fish in the fishkeeping hobby but sometimes one of the most misunderstood as well. Over the years, pet stores have grossly misled their customers and dispersed many falsehoods regarding the level of care required by betta fish. This has been heavily criticized primarily, by the fishkeeping community and several animal protection groups.

What we typically look for in a heater for betta:

First and foremost, we want our heating unit to be consistent. A heater should precisely and accurately maintain water temperatures at the set temperature at all times. Certain heaters don’t do this and it can be one of the most frustrating of things. An inconsistent heater can be dangerous, especially for a small aquarium. 

To find an adequate heating unit for our betta’s aquarium, we need to take a few things into consideration. Technically your betta should be in an aquarium that holds at least 5 gallons of water, which would require a smaller heater. We also don’t need a high-wattage heater, and instead, invest in a high-quality product.

We want a heater that won’t overheat the water, especially since betta aquariums are typically smaller, we need a heater that can operate within a small margin of error.

Now also, I’ve also heard of people using good quality heaters and overheating their betta fish because they inserted the heater in a ridiculously small aquarium, like 1 or 2-gallon. Its too small, get an aquarium that is at least 5 gallons.

Reliability

As we mentioned earlier, a betta’s aquarium is typically smaller in size and therefore allows for a smaller margin of error. I wouldn’t put a cheap heater in a small aquarium, for fear that I’ll later find my fish dead due to overheating.

Durability

Second, we want a unit that has durability. Some of the cheaper options are great in the short term but don’t generally last long. Oftentimes, cheap heaters will last between a few months to a year and will need to be replaced. This ends up being more expensive. 

I can’t tell you how many times it’s happened to me. Over the years, I’ve had my fair share of “cheap” heaters and I don’t think they’re worth it. Usually, these heaters stop working after a few months, sometimes longer, but they don’t last.

I did that for about two years, while I was in college. Surely, I must have bought the same one 3 times, after which I decided to get something better . I then purchased the Fluval heater and that one ran for 3 years, but then it got replaced with the warranty, which was a great feeling to have. Just comes to show that spending $20 more on a good heater, is going to be better financially-speaking.

Fully submersible aquarium heater. Image of Fluval E.

Submersible

In a small-size aquarium, the most efficient heating solution is a submergible heater. It’s unlikely that an in-line heater should be required for such a small aquarium. Flat-bed or substrate heaters are notoriously dangerous and inaccurate.

Special features

When choosing a heater, we have to weigh out the features of each of our choices. For example, we have a display screen, automatic shut-off features, or fish guards. So while we may not absolutely need a display screen, it’s definitely nice to have.

Safety features

I definitely like seeing products that come with safety features like automatic shut-offs and fish guards. Especially since we’re dealing with electricity and water, it’s always nice to amp on security. 

Usually, if you’re going to get electrocuted, it’ll be because of the heater. And FYI, people who get electrocuted in the fishkeeping hobby can get really hurt. From what I hear, you get a really big shock and have to go to the hospital. So let’s be safe folks and turn off the heater before sticking your hand in your betta’s aquarium.

Now, let’s address an important thing to consider when choosing the right heater for a betta aquarium, which is adjustability.

Adjustability

Many years ago I purchased a heater online and when it got to my house, I was confused, trying to figure out how to adjust the temperature of the unit. Turns out, it’s impossible. The heater only heats up to 78-Degree F and that’s it. Now, most tropical fish like bettas will be perfectly fine at that temperature.

Fluval E - Recommende betta fish tank heater for
Fluval E

Fluval E 100-Watt Electronic Heater

First up, we have the Fluval 3 100-watt heater, belonging to the mid-price range. 

This particular heater is quite popular in the hobby. What is cool about this heater, is that it has a display screen that shows the temperature of the water at all times. So that’s very convenient and helps you get a read of water temperature instantly. 

This is made by Fluval, so that’s a brand that has a really good reputation. Personally, I’ve really loved all of their products throughout the years. Most of their products, I would say, belong in the mid-range in terms of pricing. But between the low and mid-range, Fluval provides a huge step up in terms of quality. 

The heater comes with a fish-guard, so fish and plants won’t get burned.

Now obviously, this heater is no good if you have a smaller sized tank. The length of my 100-watt Fluval E is about 39 centimeters (15 inches). If you don’t have enough space vertically, you can use it horizontally. 

Available wattage: 50W, 100W, 200W and 300W.

Fluval E-Series Heater Operation & Troubleshooting Tips
  • Watts: 100
  • Range: 63 to 93 F
  • Increments: .5
Eheim Jager
EHEIM Jager TruTemp

EHEIM Jager Thermostat Heater 50W

So next up we have the EHEIM Jagger heater which is a 50-watt heating unit that is fully submersible. What I think is the best thing about this as a betta fish tank heater is that it is relatively small compared to other heaters. The length of the thermometer is about 24 centimeters has a very slim appearance.

You can also at the temperatures in increments of .5 this is something that I like because sometimes some heaters don’t give you that kind of precision.

EHEIM is just another really great brand that’s really popular in the fish keeping Hobby. I’d say that the brand is known for their emphasis on precision and accuracy. 

The EHEIM can be recalibrated using their TruTemp technology. So sometimes you’ll see with some heaters and thermometers, that their temperature readings are not accurate, which is a normal thing as things get older.

Note: When you get it out the box though, just make sure not to move the dial of the heater, or else you’ll have to recalibrate it. It’s so tempting when we get something new to just, play with all the buttons and dials.

The heater is featured with a thermometer safety control which shuts it off when it become dry.

  • Watts: 50
  • Range: 62 to 88 F
  • Increments: 1 F

Fluval M-Series

Fluval M-series heater
Fluval M-series heater

An alternative to the Eheim Jager is the Fluval M-series, which are also built long. The main difference between the two products is that the M-series heater don’t have a calibration. Both a submersible.

Aqueon Adjustable Pro Aquarium Heater

Aqueon Pro
Aqueon Pro

So this is a heater that I have been using and the past few years they’ve recently come out with a new 50-watt, Which I think is even better for a Betta Aquarium. The new version is quite small inside when you compare it to other heaters. It has this very slim and mat black finish that I think many betta fish owners will enjoy. 

I find that Aqueon also does well at this price range. For example this product is part of their higher-end “pro” product, which I’ve come to trust over the years not sure if I would recommend the cheaper products.

Tetra HT Submersible Aquarium Heater

The Tetra HT model is inexpensive and simplistic.

The heater comes at a preset temperature of 78 F. You cannot change temperature settings. Most tropical fish are comfortable at that temperature.

Be wary of the so-called betta fish heaters

These are heaters that are specifically branded as betta fish heaters and address a casual audience within the market. Many manufacturers, like Marina, Top-Fin, and Aqueon provide their own version of this type of product. To be honest, I don’t like them. In my experience, I have found these to be unreliable, and grossly inaccurate with the exception of the Marina betta heater.

Marina betta fish heater
Marina Betta Tank Heater

Marina Betta Tank Heater

I have used the Marina Betta heater for over 4 years now on a 6-gallon betta tank. This is marketed as a betta fish heater, and surprisingly it is a good quality product. In fact, I have never had any issues with this model. However, I would recommend other products in this price range. However, if you’re looking for a small heater, then this is perhaps the smallest, yet permissible heater you will find. One good thing about this model is that it’s very small and compact.

Best Betta Fish Tank Heaters For 5-Gallon tanks:

The list of tiny yet high quality heaters.

  • EHEIM Jager Thermostat
  • Aqueon Adjustable Pro
  • Fluval E 100

Best Betta fish tank heaters for 3 gallon tank

Since this type of aquarium is really small, I’d recommended the Mini-heater by Aqueon. For a 3-gallon tank, it’s better to choose the 7.5 watts model. Alternatively, the Marina Betta Heater, as mentioned earlier, is good quality and relatively small.

Best betta fish heaters for 10 gallon + tanks

  • Fluval E 200

Frequently Asked Questions

What temperature do betta fish need?

Between 78 and 80.6° Fahrenheights (or 25 to 27° Celcius).

How to heat a betta tank without a heater

Keep it close to sources of heat and away from cold sources.

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