5 Best Aquarium Heater for Betta Fish

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Since we are talking about tropical fish here, you are definitely going to need a heater for your aquarium.

For the Betta fish, the water temperature has to be somewhere between 72 and 85 °F (24-28 °C). That is what mostly imitates their natural habitat.

Bettas simply can’t get used to room temperature because it is too cold for them so don’t bother trying. A good heater is not that expensive and it is definitely worth the investment.

In this article, we are going to show you the best models that you can get right now in the market.

If you decide to buy an aquarium kit for your betta fish, you can skip the process of finding a good heater, because most kits contain a heater as well.

Installing a heater to your aquarium is really not a big deal and your Bettas are going to appreciate it a lot. The point is to not settle for all the cheap heaters that are available now online.

Although those promise a lot, you are really going to regret buying them once you try them out at home.

Instead of throwing your money out the window, check out the models that are actually good and worth buying!

Best Heater for Betta Fish

By installing a heater that works properly, your Betta Fish is never going to be stressed. If the water is too warm or too cold for them, they are simply not going to feel well. Even the highest room temperature is around 70 degrees Fahrenheit which is slightly below the minimum.

Once you set the temperature on your heater, it needs to stay constant. Bettas don’t like temperature fluctuations either. By reading the reviews below, you are going to be well-informed about the best heaters available online. Once you get to the end of it, it will be obvious which one to choose.

Preview Heater Name Amazon Page
1. Freesea 50W Mini Heater
2. Hitop Adjustible Submersible Heater
3. Cobalt Aquatics Flat Neo-Therm Heater
4. Hygger Mini Glass Aquarium Heater
5. Freesea Adjustible Aquarium Heater

Now let’s see what are the advantages of these five heaters:

1. Freesea 50W Mini Heater

This 50W heater by Freesea is optimal for any 10-gallon Betta Fish aquarium. This one looks great and it’s completely submersive. You don’t need to worry about even the slightest bit as it’s a high-quality waterproof device.

It looks really simple with its oval shape and ribbed sides and it’s very easy to use. Inside this little black heater, there is a control chip that monitors the current temperature and adjusts itself if necessary. It makes sure that the water is constantly warmed up to the set temperature.

Whenever you want to adjust it, you just need to push the external button and set the desired temperature. There is a LED display on it with red digits that shows the current heating status. A quick glance on it and you already know it.

If you are looking for something simple and effective for your Betta Fish, then we can only recommenc you this Freesea Mini Heater.


2. Hitop Adjustible Submersible Heater

The Hitop is one of those heaters that have a decorative design. There is a wide range of models to choose from depending on how big your aquarium is. The best thing about this heater is that the chance of circuit failures are basically zero.

Since the case is made of PTC material, it does not emit an amount of heat that would be dangerous for your fish to go close to. This Hitop model is adaptive, using exactly as much power as needed based on the current temperature. While it can quickly warm the water up when it’s too cold, it will be pretty much inactive after it reaches the set temperature.

The product comes with a stick-on thermometer where you can keep track of the temperature in the tank at any given moment. The Hitop looks great, it is completely safe and it will do an outstanding job keeping your aquarium warm.


3. Cobalt Aquatics Flat Neo-Therm Heater

This heater by Cobalt Aquatics is a rather minimalistic-looking, yet highly effective Betta Fish heater. If you have a 5-6 gallon aquarium, then you simply can’t go wrong with this one. Fish keepers who value quality don’t think twice when they see this heater in the market.

What you get is a device that will actually last for years, keeping the water consistently warm day by day. You can already tell by its design and appearance that we are talking about a high-quality product here because it doesn’t look cheap at all.

Even in the rare case when something goes wrong with Cobalt, you are going to be able to fix it in no time. After all, when your heater stops working, there is no time to waste. You need to quickly take care of the issue because Bettas simply can’t stand cold water.

Thanks to the minimalistic design and size, no one is going to notice that there is a heater in your tank. It allows you to set the temperature easily and also to see the current and set temperature.


4. Hygger Mini Glass Aquarium Heater

You can buy a Hygger Mini Glass heater in the following two wattages: 50W and 100W. The perfect tank sizes for these are 10-gallon and 20-gallon tanks respectively. It is an oval-shaped, fully submersible heater that allows you to set the temperature with the button attached to its wire.

The LED display shows red digits in the center of the device where you can see the current value. It basically doesn’t matter at all if it gets out of the water while the heater is active. The Hygger is instantly going to shut off, ensuring safety.

It is not only waterproof, but also highly durable thanks to the double seal material and the quartz glass it is made of. No matter which value you set it to, the maximum deviation is going to be only 1 degrees Fahrenheit. The high-quality design guarantees that this heater is going to work properly for years without any rusting.


5. Freesea Adjustible Aquarium Heater

You can get this Freesea heater model in many different wattages depending on the size of your aquarium. Nevertheless, it is a great choice for keeping Betta Fish. You can easily warm the water up with it to that ideal 78 degrees Fahrenheit and also keep it there.

It is easy to use and the product also comes with a diving thermometer that will conveniently show the current temperature in the tank. For safety, this Freesea model has an automatic shut-off function. However, its most useful feature is that it automatically keeps the temperature constant.

After you set the temperature on it, the device will start to heat the water up. Once the target value is reached, it will shut off until the water gets colder. This heater is designed with durability in mind, not to mention that it looks awesome with that transparent cover.

The in-built overheating protection will ensure that the water is always going to be convenient for your Betta Fish.


Do Betta Fish Actually Need a Heater?

The main reason why Betta Fish needs a heater is simply that they are tropical fish. In the wild, they live in rice paddles, river basins and narrow streams where the water is warm. Therefore, the water in your aquarium should be warmer than room temperature.

After all, we are not living in 72-85 degrees Fahrenheit in our house. We would find that uncomfortably warm. Ensuring warm water for your Betta Fish with a set value that doesn’t fluctuate is essential. It will prevent them from being stressed and keep them healthy.

Bettas have this instinct to change places when the conditions are not right. If the water is too warm or too cold, they might eventually decide to jump out of the tank. They do this because they hope to find another body of water where they feel better. Finding your fish on the floor is definitely not something you want to experience.

How to Choose a Heater for Betta Fish?

It will mostly depend on the wattage whether the heater is going to make the water warm enough or not. You should follow the 5 Watt per gallon rule for this. If you calculate it properly, then you are going to be able to maintain a consistently warm temperature in your aquarium.

A nice tactic is to install two small heaters instead of just a big one. You put them in two different spots and they are going to do a great job heating up the water. If you buy a cheap heater, you can fall into the trap of getting one that is not adjustable.

Since Betta Fish need a specific temperature, adjustability is key. Also, the temperature is not constant in the room either. On colder days, you will need to set your heater to a higher temperature. Most importantly, the heater has to be safe for your fish to be around.

Good heaters are rated for submergence, which means that it’s going to electrocute neither you nor your fish.

What is the Best Temperature for Betta Fish?

It is going to be perfect for your Betta Fish if you can keep the water temperature between 78 and 80 degrees Fahrenheit. This is easy to do with a good heater and thermometer. Any greater fluctuation can cause your Betta’s immune system to become weaker, thus leading to health problems.

For example, one of the common diseases this species can get is Coat Syndrome. This is a bacterial disease that is a result of overheated water. The difference between the ideal temperature and the 72-85 Fahrenheit range is quite big.

If the temperature is ideal, your Betta Fish is going to thrive and be energetic. If it’s near the minimum or the maximum, then he is going to survive but it is not going to be as comfortable for sure.

Betta Fish Minimum and Maximum Temperature

The maximum temperature that Betta Fish can endure is 86 degrees Fahrenheit or 30 degrees in celsius. It might not seem that much but it’s actually highly unpleasant for them when the water is that warm. In case you set the thermometer properly, you are going to notice it on their behavior that something is wrong.

If the water is too warm, your Bettas are going to start to swim in a weird way. They are also going to seem overly energetic, swimming back and forth stressed. In case you notice something like this, then immediately check the water temperature.

It can be severely damaging for them in the long term if the temperature is higher than 86 Fahrenheit and it can be even fatal. Keeping them in cold water, on the other hand, will result in sloppiness and loss of appetite. This is when you go below 70 degrees Fahrenheit. Either way, their immune system is going to suffer.

Where the Heater Should be Placed in Betta Aquarium?

You cannot just install the heater anywhere in your aquarium because it should evenly distribute the heat to the whole tank. In order to guarantee this, make sure to put the heater where the filter inlet-outlet is. If you have bought a submersible heater, then place it near the bottom of the aquarium.

You have to place it in a horizontal position in order to maximize its effectiveness. In case you have a vertical tank, then it is a better idea to position it vertically. It really depends on the type of aquarium you have but you can also test it out by turning it on and measuring the water temperature.

Another important thing is that there shouldn’t be any plants or decorations near the heater. You want to ensure that the water circulates freely around it, otherwise, it is going to have a hard time heating up the whole tank.


We have introduced you to various heaters, now it is up to you to choose. These are all high-quality models that are more than enough for keeping Betta Fish in your aquarium. In the end, every home aquarium is different so only you will be able to determine which one of these heaters fits yours the most.

What you need to keep in mind when looking for a heater is to not buy one that can potentially overheat the water. Sometimes, weaker heaters are more than enough. The goal is to heat the water up to the recommended temperature for Bettas and keep it constant.

As long as a heater can guarantee this at least for an upcoming couple of years, you are going to be satisfied with it.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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