Do Betta Fish Need A Heater? [Complete Guide]

Bettas are often regarded as one of the cheapest, and easy-to-maintain aquarium fish you can find. Not only are they easy to care for, but they are also gorgeous and obviously, on top of every consumer’s list. Only on rare occasions, you will find beautiful, and colorful tropical fish get raised in a gallon of water and survive. With bettas, that’s possible. But, that’s not why we are here, right? Anyways, in this piece, we’ll be highlighting an important question, which is: do betta fish need a heater?

Asides answering the question, we will also take a look at everything you ought to know about appropriate water temperature and management when dealing with a fragile creature such as the betta fish. unfortunately, many bettas die untimely due to the owner’s negligence. Most of the time, we don’t spend enough time with our water, pet, and that is not proper. If you’ve just got your betta a new aquarium, you may probably be wondering whether or not your betta fish needs a heater. In this piece, we will be sharing with you the complete guide. Also, we will put a spotlight on the optimal temperature your water pet will optimally thrive in, the side effects of water temperature fluctuations, how to keep your tank warm in case your heaters damaged, or lastly, how cold water could harm your betta fish.

Do Betta Fish Need A Heater? Why?

The simple answer to that is Yes. If you don’t own a heater right now, then you need to get one for your betta as soon as possible. Fish are delicate creatures when it comes to water temperature. They react to the sudden change of water temperature in the tank. But, when the fluctuation becomes frequent, it could be fatal for your betta. Cold weather which when experienced by humans is often regarded as a nuisance is more of a fatal experience for that water creature. In short, the best thing to do is to try as much as you can to protect your betta from extreme water temperatures. Both hot and cold water isn’t good for your fish. So the best thing you can do for your betta fish is to get a heater for him.

You can only get by without a heater if and when the room where the tank is located remains at a fixed temperature. Even in this scenario, we all know that the room temperature drops to its lowest. So, that’s one of the things to consider if you are taking that ‘route’. The same also applies during the winter. To be in a safe zone, your best bet is to opt for a heater to save yourself the hassle of wondering all day whether or not your betta is doing fine.

Moreover, in the long run, heaters aren’t as expensive as one might think. Invest in one and help your betta stay in a conducive environment. Later on (this could be in another article entirely), we will be discussing the side effects of temperature shock, the symptoms and how to treat your betta in case of a temperature shock.

Here’s our best pick from Amazon!

The Right Water Temperature for Betta Fish

At first, You need to understand the right temperature that suits a betta fish. The ideal water temperature for your water pet is 78 to 80-degree Fahrenheit. Even though bettas are believed to live in even colder temperatures, for domesticated ones, that won’t be ideal. The aforementioned temperature range will help keep your betta in good shape. However, when the tank temperature drops, this could spell doom for your betta if not treated on time. When the tank temperature exceeds the 85-degree mark or fall below 74-degree Fahrenheit, it could put your betta’s life at risk or affect the overall health of your betta.

Bettas are naturally found in the heart of Malaysia, Cambodia, and Thailand. They live in rice paddy fields and shallow ponds, where they can get protection from lots of plant cover. Bettas thrive in warm conditions. The tropical location provides the betta with the needed stable temperature. To keep your betta from infections and diseases, you must maintain the water temperature.

How Bettas React to Low Temperatures

When a fish such as a betta fish is kept in low temperate water, it’s a time bomb, as it’s a matter of when rather than if the betta will negatively react to it. One of the many things that will happen is the decrease in the rate of metabolism. Bettas are cold-blooded and when they are placed in cold water, it slows down their color development and growth rate, and in extreme conditions could lead to a total shut down. The important thing to note is that a betta’s body is incapable of repairing its body part when the betta is kept in cold water.

That’s not all, asides these aforementioned side effects, the betta’s immune system will be damaged. Meanwhile, the immune system is designed to help the betta fight diseases, infections and stress. you know what it means when this system is damaged. No matter how well you care for your betta’s tank, microbes will always exist in it. These microbes are responsible for all sorts of diseases and infections. So, when the immune system designed to fight off these microbes gets damaged, it will spell doom for your betta, which can be fatal.

Lastly, the low water temperature can also disrupt the development of your betta’s eggs or the growth of her fry. Young bettas hardly survive low water temperature. You should take a look at this article on “How long can betta fish live in cold water”

Signs of Temperature drop in Betta Fish Tank

How do you know if your betta is in a fluctuating or low water temperature? One of the things you’ll notice is that your betta will start to move slowly. Bettas are quite lively, but when they are subjected to low water temperature, things start to go south for your betta. As time goes by, your betta will start acting weird with its sluggish movements. In general, cool water tends to slow down your betta.

Also, parasites will start to attack the betta’s fins and skin. At this point, treatment and medications won’t ease the stress and fend off the disease. Rather, taking care of the betta’s environment as a whole will be the perfect thing to do. Diseases or infections such as ulcers and split fins are usually lurking around in the betta’s tank. Not treating the root cause of the infection will be tantamount to the betta’s death. In extreme cases, this could be fatal for your betta. In summary, your betta will start experiencing things like

  1. Slow, sluggish movement.
  2. Stays motionless, and sit close to the water heater.
  3. The betta will start losing its colors.
  4. Susceptible to different infections and illnesses.

How Bettas React to Hot Temperatures

What will happen to a betta that’s kept in hot water? remember, the ‘hot water’ term used here is used loosely, as what is termed as too hot for a fish could be warm for other organisms. But what will happen to the betta? When a betta is kept in a tank filled with water of about 86 – degrees Fahrenheit, it will start to experience overheating. That doesn’t sound right!

One of the first signs you will notice when betta is kept in a hot tank is that your betta will start swimming weirdly. As a cold-blooded animal, bettas can only live in an environment with a similar temperature. But when the temperature becomes too hot for the betta, it will cause your betta to gain more energy. Interesting right? Well, as good as that sounds, it’s not actually a great thing for your betta as it could lead to stress, wicking out your betta’s energy. To deal with this, get a fan to blow over the top of the tank. It will cause evaporation to occur, but at a much faster rate, which will ultimately keep your tank cold.

Why a Bigger Tank is the Right Choice for Your Betta

While it’s easy for the water temperature in a small tank to drop rapidly, a bigger tank on the hand conserves a lot of heat and cools slowly. The temperature in a small tank tends to drop pretty quick. In contrast, a bigger tank conserves more heat, keeping your betta warm for a very long time.

The recommended minimum volume of water for a betta is 2.5 gallons. Having that amount in a small tank won’t be ideal as the water temperature will drop very fast. Drastic temperature changes are not ideal for your betta, and that is one thing you won’t get with a bigger tank. We recommend getting anything above 5 gallons for your betta fish.

In a bigger tank, the water tends to stay at a constant temperature. When you go for tanks that are 5 gallons or above, you will ultimately be keeping your betta safe from the effect of drastic change in temperature. Having a heater in a 2.5 – gallon tank doesn’t mean that a sudden change in room temperature won’t affect our betta negatively.

Types of Heater for a Betta Fish Tank

Betta owners should know that bettas require warm water to function optimally. Staying at room temperature isn’t good enough for your betta. Most of the time, bettas are kept in bowls or small times, as such, heating is required. In the next section, we will be comparing some of the different heaters out there.

Adjustable vs Preset Heaters

The first of such comparison is pre-set and adjustable heaters. Adjustable heaters are of two types. One has an adjustable knob. The second type of adjustable heater is the one that comes with temperature markings which will allow users to specifically chose the number manually. These adjustable heaters come with lights that turn on when the heater is on and putting out the heat. You can adjust the heater’s set point. But to do that, you must first place a thermometer in the betta’s tank. Next, turn on the heater and wait for the water temperature to rise to the desired temperature level. Finally, turn off the light off; the setpoint temperature will be maintained.

Pre-set heaters, on the other hand, don’t have knobs for temperature adjustment. Instead, what you’ll get is a single preset temperature, which is the 78 degree-Fahrenheit. Users can’t adjust the temperature, what you can do is to turn off the pre-set heater once the water – temperature gets to the setpoint. Some of the benefits and positives of opting for a pre-set heater are its affordability and portability. Pre-set heaters are quite small.

Partially vs Fully Submersible heaters

Asides the pre-set and adjustable heater comparison, one other comparison that’s worth highlighting is that of the partial and fully submersible heater. A submersible is any machine that can be submerged in the water. A perfect example of such machines is the submersible heater. Now, being partially or fully submersible is a different topic (which we will be dealing with shortly) entirely. A partially submersible heater is one that functions by been placed above the waterline. A portion of the heater (not all) is placed partially in the tank. Even though partially submersible heaters are more expensive than the fully submersible heaters, they are not as versatile as the fully submersible heaters. Fully submersible heaters, on the other hand, are cheaper and are more versatile than the partially submersible heater. We recommend using the fully submersible heaters as they are more functional and versatile compared to the partial submersible heaters.

The heater’s shapes

In the past, there was more of the torpedo-shaped heaters, manufacturers are now producing more of the smaller heaters. Heaters now come in different shapes. Heaters now come in different shapes. While there are circle-shaped heaters, which fits perfectly in the bottom of bowls, we also have rectangular-shaped heaters which can be placed directly in the tank. Furthermore, to answer the question ‘do betta fish need a heater?’, you need to comprehend the heater’s shapes which we’ve successfully explained.

Even though these heaters are of different shapes, they all have one thing in common, and that is the fact that they all energy consumption and are all made from shatterproof materials. Flat heaters are designed in such a way that you don’t have to place them behind any decorations. Just place them underneath the tank or bowl.

The Thermometers

The dynamism of having heaters in your tank won’t be complete without highlighting the role of the thermometer in all of these. Heaters hardly come with inbuilt thermometers. What this simply means is the fact that you have to get an external thermometer as it is impossible to get an accurate reading of the water temperature without one. We recommend a small stick-on thermometer. The two things you should avoid while using the heater is overheating and underheating.

For a huge tank, we recommend using a stick-on thermometer. On the other hand, using a stick-on thermometer in a small tank will be visually poor. A standing thermometer will be the perfect choice for a small tank. When using a standing thermometer, all you have to do is place it in the tank temporarily, and when you’ve taken the temperature, you can then remove it.

How to Choose the Right Heater For Your Betta

When it comes to choosing the right heater for your betta, there are some things you need to take note of. It’s no gainsaying the fact that there are tons of heaters out there today. Choosing the right one can be complicated. Let us highlight some of the things to consider when getting a heater for your tank.

  • Fully submersible heater (Recommended)

Just as we’ve mentioned earlier, a fully submersible heater will always be the best choice. They are more efficient when compared to the partial submersible heaters. When it comes to heating your tank, they do a better job. Working with a submersible that should only be partially submerged in the tank can cause a lot of troubles and hassles as you’d have to make sure that they aren’t fully immersed in the tank.

    ·  Glass beats plastic

Asides choosing a fully submersible heater over partially submersible heaters, one other thing you need to take note of is the material used for the tube. A glass tube is way better than the plastic tube. Scientifically, a glass tube works efficiently when it comes to heat transfers. They also look much better when compared to plastic tubes. Lastly, they are easy to maintain, unlike plastic tubes which tend to stain quickly and are relatively difficult to maintain.

   ·  Water heater with thermostat

Overheating can easily happen when you heat your tank with a heater that has no thermostat. The importance of thermostat can never be overemphasized. Lots of people have had the experience of overheating their tank because they own a small tank. It is very easy to overheat a small tank. To avoid that (without trying to sound like a broken record), you must opt for a bigger tank.

A thermostat will help turn your heater off as soon as it gets to a certain point. When the heater gets to its predefined temperature, it turns the heater off automatically. What you get with the thermostat is that it reduces the risk of accidentally overcooking your betta while trying to heat the tank.

Other things to consider when choosing the right heater for your tank include:

  • It should allow between 3 to 5 watts for every gallon of water.
  • The heater you go for should fit perfectly in the tank without having to touch the decorations, gravel, and filter.
  • The right heater should fit when placed in a corner and transfer heat perfectly.
  • Some heater operation you need to know about.
  • There are certain rules you need to be conversant with when working with a water heater.

Understanding Tank Size and Water Temperature Stability

When answering the question “do betta fish need a heater”, you need to understand the tank size. Most times (if not most of the time), unheated water tends to stay constant but resonantly changes along with the room temperature. Depending on the volume of water in the tank, the temperature varies by a few degrees.

For instance, when a temperature in a room drops sharply from 75 degrees to 70, the water in the tank won’t drop quickly. Sometimes, it can take hours before the water in the tank drops too.

How to Operate The Heater for Betta Fish

Handling water heaters should be done cautiously. There are certain things you can do to help keep your betta and yourself safe when handling a water heater. Some of these things include:

First and foremost, you need to fix a thermometer in the tank. You need to have one installed in your betta’s tank to know the actual temperature of the tank.

You need to check the water temperature frequently. To be on a safer side, check before you go to bed, and check any time you wake up first thing in the morning. That way, you get to know if the heater is faulty. We are still on the question ‘do betta fish need a heater?’.

Before plugging the heater, make sure it sits in the tank for at least 1 hour. Also, you should let it stay in the water for at least one hour before taking it out. Thus, what this does is it lets the glass reach the same temperature with the water temperature, preventing possible cracking.

You need to know how the thermostat in your betta’s tank works. While some thermostat lets you set betta owners set a temperature, others just have a ‘more’ or ‘less’ option.

If you have Partially submersible installed in your betta’s tank, then you should observe the water line mark concerning the water level. When the water gets higher than it should, it could lead to electric shock. One which could harm you or your betta. Meanwhile, not filling the tank with enough water will ultimately heat the tube, causing it to explode.

How to Treat Betta Fish if the Heater is not Working Properly

There are times when your heater gets damaged and you need to heat your betta fish tank. In an emergency, there are certain things that you can do to help save your betta’s life. One of the components to look at when answering questions such as ‘do betta fish need a heater?’ is knowing how to treat your betta fish in an emergency situation.

Before we begin, we need to state clearly that there is a need for you to get a bigger tank. Just as we’ve rightly stated earlier, a bigger tank means more heat energy will be conserved in the tank. This will give you more time to get the heater fixed or get a new one. So, some of these things to do in an emergency include:

1. Heating tank with a candle

Candle heating is one of the reliable options you have in a situation such as this one. All you have to do is place a candle closer to the tank. Just make sure the candle is not burning soot. Rather than going for glass-encased candles, you should opt-in for votives and freestanding tapers as they tend to release more heat than the glass-encased candles. You can also buy a candle – heater. These candles are designed to heat the aquarium. You can use it to warm up your fish tank as well as the other rooms.

2. Turning up the heat in your home

To use this method, you need to be sure that you’ll get your water heater fixed or find a lasting solution to the temperature crisis. It works well if you are using a small tank as its only a temporal ‘not – so –quick’ fix. By heating your house, you will also be heating your betta’s tank.

3. Floating hot water in bottles

The next option you have is to float hot water in any usable bottle you can find. How do you do this? Pretty simple. First, you need to take out 1 gallon of water (don’t worry, you will put it back in the tank later). Now, you need to get hot water from any source (it could be from a faucet too). Next, you float it in sealed-up bottles in the fish tank. Note, avoid boiling water, this will kill your betta. All you need to do is to make sure that the water is kept at a comfortable level.

Lastly, you’ll need a thermometer, this will help you track the temperature of the water. That way, you will know when it’s the right time to change the bottles or take them out. Once you are done heating the tank, simply add the previous water you’d poured out from the aquarium. But, if you wish, you can add a new one.

4. Heating with the sun

You can warm your fish tank with the sun. In case it’s quite sunny and you don’t have any other option, the sun could be the answer you are looking for. When it’s relatively warm outside, you can do the opposite and work with the sun. yes! put your tank in the sun, this will warm up your betta tank. But be careful, leaving your betta out in the sun for a long time will heat the tank to an uncomfortable state. While the tank is kept outside, always check to see that the water is not overheating.

5. Using an electric blanket

If your heater is broken, another option you should try is the electric blanket. If you are not comfortable with taking your fish tank outside in the sun, you should give this a try. All you have to do while the tank is wrapped up in the electric blanket is to make sure that temperature doesn’t rise above the appropriate level to avoid overheating.

Speaking of blankets, you should also make use of a towel. Try wrapping towels around your tank to give it that warmth it needs. Even though the sudden light change will shock your betta, it won’t be as stressful as staying in a cool tank.

6. Improvising

Asides the options we’ve highlighted, there are other ways to go about heating your tank. One of which is moving a lamp close to your tank, and let the light focus on it. You could also use a hairdryer. Clearly, these options are short term. They aren’t great as long term options. Simply put, these options should only be tried if and when there are no other options.

Where to Place Your Betta Fish Tank.

The aquarium location is pretty important, as it will determine the overall temperature of the tank where your betta resides. Rather than placing your fish tank closer to a ‘bright’ window, the opposite should be the case. The opposite being to take it farther from you the bright window. Get this, warm sunlight won’t help you keep the tank’s temperature at the appropriate level. This is faulty thinking that should be addressed. What you get from exposing your betta tank so when placed close to the window is overheating. Look for a spot in your home that’s far from the reflection coming in from the opened window.

How long will a betta survive in a cool temperature?

One of the questions you’re probably going to ask is how long a will be live for without proper heat? A water temperature that is quite higher than 78 degrees Fahrenheit, then your betta will survive for a long time in good health. But, when a betta is placed in cool water, then it’s a matter of days. This is basically one of the last things to look out when discussing if your betta fish need a heater.

Best Heaters for your Betta Fish:

Here are some of the best heaters out there for your betta fish:

Eheim Jager Betta Fish Tank Heater

One of the best heaters for bettas is the Eheim Jager Betta Fish Tank Heater. In the league of the reliable heater, this one stands out. It is known to steadily maintain the temperature of every tank. All you have to is put place it the preset range and you are good to go. The secret to its accuracy lies in its ability to recalibrate. When you talk about reliable betta tank heaters, the Eheim Jager Betta Fish Tank Heater.

It’s made of quality glass with the ability to withstand a whole lot of pressure, this is a pointer to how durable the heater is. With an electrical rate of 300 watts, and an indicating light which helps users know whether or not it is working. One other feature that makes this heater unique is how it tends to go off when taken out from the tank (from the water). This safety measure makes it even better than so many other tank heaters out there.

It also has a mounting bracket and a suction cup which helps for an easy installation. When you talk about some things that make a heater top-notch, you need to look at some things such as the durability, accuracy, and cost; and on that ground, this heater tops it. For every newbie out there, this is one heater that’s easy to handle.

Fluval Marina Submersible Heater for Aquarium

Another good heater for betta fish is the Fluval Marina Submersible Heater for Aquarium. It is also classified as a mini heater due to its size. So, it’s safe to say that it is unarguably one of the best mini heaters out there, thanks to its portability. Small tanks obviously don’t have enough space, but being able to make use of a heater that can manage this space efficiently means a lot. The heater is fully submersible and also completely waterproof which makes sure that the circuit board and other internal components are kept dry even when submerged in water. In addition to being water-resistant, the heater is also impact-resistant, thanks to its carefully designed body. One of the importance of being impact resistance is that if and when it accidentally drops, you won’t have to worry about your heater being damaged.

Speaking of the heater’s features and capabilities, it comes with suction cups and brackets which both make it easy to use. With the suction cups and brackets, you’ll be able to set it up in seconds, while maintaining it is quite easy too. However, this heater can only be mounted in one vertical position. But the position should not be a problem since it’s a small heater to start with. To get started, all you have to do is to plug it in and you’ll be good to go.


If you want your betta to live optimally, you want your water pet to live for 4 to 5 years (which is possible), then one of the things you need to stay conversant with is the water temperature. A slight change in temperature can hurt your betta. With the tips that we’ve highlighted, I think you now have a ‘betta’ understanding of the situation and can easily handle the cases of water temperature dropping suddenly. Read through this piece that we have written about bettas. So after all the discussion above we can answer the question, do betta fish need a heater? Of course, they do.

Leave a Comment