Best Aquarium Heater & Buyers Guide

The key to keeping your aquarium’s inhabitants healthy and happy is to provide them with a proper environment that resembles their natural one as much as possible. Unlike humans and other mammals, fish are coldblooded. This means that they rely on the water temperature to get warmth. Therefore, you will need to use a reliable aquarium heater to ensure that your aquarium’s ecosystem thrives.

The tricky part about picking the correct aquarium heater is learning what features and specifications to look for. Here is where our expertise comes in. We have reviewed tens of aquarium heaters of all types, and today we are going to present the top 9 best aquarium heaters that you can find on Amazon. We are also going to present a buying guide and answer the internet’s most asked questions about aquarium heaters, so make sure to stick around until the end.

Cheap & Good

Our Favorite

Customers Choice

Orlushy Submersible Aquarium Heater

Cobalt Aquatics Flat Neo-Therm Heater

Orlushy Mini Aquarium Heater

Power (Watt)

100 - 500

25 - 300

50 - 100


8.5 lbs

0.5 lbs

0.55 lbs





Our Rating

Aquarium Heater Buying Guide

Considering that fish are cold blooded and that they rely on the water temperature to keep their bodies warm, you need to make sure to buy the best aquarium heater for your setup. Otherwise, you will end up with a fish tank that is not heated correctly, and the ecosystem will not thrive. If you are not sure what features to search for when looking for the best fish tank heater, then you don’t need to worry because we have your back. Check out our aquarium heater buying guide below:

The Size of the Aquarium Heater

The first thing that you need to take into consideration is just how big you want the aquarium heater to be. This is an important factor because it determines how much heat the aquarium water will receive and if it can reach the desired level. If you are planning to set up a massive 80 gallons aquarium, then you will need to go for something big such as the Orlushy Submersible Aquarium Heater that is the best choice for big tanks.

Since we are talking about the power of aquarium heaters, we want to mention that the rule of thumb when selecting the right wattage option is that you need between 2.5 to 5 watts per gallon of water of volume. However, the number of watts can change depending on the room temperature and the desired water temperature level. You will need more power if you want to reach 96 Fahrenheit.

The Types of Heaters

There are three types of aquarium heaters, and choosing the right one is essential for providing your fish with a safe and welcoming environment. The first type is submersible heaters, such as the Cobalt Aquatics Flat Neo-Therm Heater that can be fully submerged in the water. The great thing about this type is that they can be easily mounted near the substrate. The second type is the heating cables. They are best for smaller tanks where you don’t want to ruin the view with the hardware of the heating device. The third and most easy to install type is hanging/immersible heaters. They hang over the top of your aquarium, and the heating element is the only part that goes underwater.

Never Buy Used

If there is one thing that all aquarium hobbyists will agree about when it comes to purchasing fish tank heaters, then it has to be the fact that you should never buy a used one. Even though heating devices are built to run in water, you are still dealing with electricity, and it’s always better to be safe than sorry. You don’t know if it runs correctly or if it will cause issues that might hurt your fish, or even you!

Durable Materials

Did you know that if not installed properly, heaters can explode? This happens when the heater is plugged in, but not placed in water. The glass tube heats up, and it either shatters or explodes. This is why you need to make sure to purchase a device that uses durable materials. The perfect example here is the Mylivell Water Heater that uses a quartz tube (explosion-proof). The Cobalt Aquatics Flat Neo-Therm is another good choice here because it is encased in a durable and shatterproof material.

Placement of the Heater

One of the most overlooked factors when it comes to finding the best aquarium heater is the placement of the device. If they are submersible, then the heating element needs to be placed inside the water to distribute the warmth properly. There are also immersible heaters that need to be placed as close to the aquarium filtration system as possible. The reason behind this is that immersible heaters will make sure to warm the water as soon as it comes back in to provide the optimum conditions for the aquarium’s inhabitants.

The best Aquarium Heater

1st Cobalt Aquatics Flat Neo-Therm Heater


  • Dimensions: 2.25 x 1.25 x 11 inches
  • Weight: 0.02 pounds
  • Color: Black
  • Compatible aquarium size: up to 40 gallons fish tank
  • Power: 150W
  • Temperature range: 66°F to 96°F

We are going to kick things off with a premium aquarium heater that is available in seven power options. Thanks to this, the Cobalt Aquatics Flat Neo-Therm Heater makes it easy for you to find the best option for the size of your fish tank. Talking about simplicity, we want to highlight the user-friendly interface of the device. The fish tank heater is equipped with an accurate, one-touch system that allows users to set the temperature between 66-96 Fahrenheit. With a simple touch of a button, the water temperature of your aquarium is always going to be at safe levels.

This is a fully submersible aquarium heater, and it ships with a modern and compact design. Therefore, you will not have any issue finding a good spot to place it close to the filter so that the water can be warm as soon as it comes back in. Another cool feature that we want to highlight is the LED screen that shows all the essential info, such as the current temperature, for example. However, the selling point of the Cobalt Aquatics Flat Neo-Therm Heater is that it is built from durable materials. In fact, the fully submersible aquarium heat is equipped with a shatterproof outer-casting that makes it almost indestructible.


  • Available in seven power options;
  • Fully submersible;
  • Compact design;
  • The outer layer is shatterproof;
  • Easy to use;
  • LED screen;
  • It prevents overheating;
  • 3-year warranty.


  • It is pricey.
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2nd Hygger Submersible Thermostat


  • Dimensions: 15.12 x 5.98 x 2.44 inches
  • Weight: 2.01 pounds
  • Color: Black
  • Compatible aquarium size: up to 120 gallons fish tank
  • Power: 500W
  • Temperature range: 32°F to 104°F

Hygger is a leader in the aquarium industry, and the submersible thermostat featured in the picture above is one of its bestselling products. What makes the Hygger Submersible Thermostat such a popular product is the fact that it uses fast heating technology. Therefore, your aquarium’s inhabitants are never going to be cold. If this isn’t impressive enough, then you should know that the device features a fully automatic control system. This means that you don’t have to do anything else other than to set the desired temperature. The fish tank heater will run automatically by itself. Since this is a submersible aquarium heater, then it shouldn’t come as a surprise to find out that it is equipped with strong suction cups that guarantee it always stays in the right position.

The manufacturer behind the submersible thermostat is renowned for only using premium materials. The Hygger Submersible Thermostat is not an exception to that rule featuring a high-quality quartz glass tube. This is one of the most durable materials available for fish tank heaters, and it is explosion-proof. Moreover, the device features a black plastic guard on the heating tube so that it doesn’t ruin the view. If you are wondering how you will be able to see the temperature of the aquarium water, if the heater is fully submerged, then you should be pleased to know that the manufacturer has equipped the device with a LED screen.


  • Fully automatic control;
  • Available in two power options;
  • Fast heating technology;
  • Simple installation;
  • Overheating protection;
  • High-quality quartz glass tube (explosion-proof);
  • Ideal for both freshwater and saltwater tanks;
  • LED screen.


  • The suction cups lose power over time.
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3rd Fluval E Electronic Heater


  • Dimensions: 1.7 x 4.8 x 16.5 inches
  • Weight: 0.4 pounds
  • Color: Silver
  • Compatible aquarium size: up to 65 gallons fish tank
  • Power: 200W
  • Temperature range: 66°F to 86°F

If you did some research on the best aquarium heaters before coming here, then this is probably not the first time that you see the Fluval brand, and there is a good reason for that. Fluval is a fan-favorite by aquarium hobbyists because of the premium products that it sells. The Fluval E Electronic Heater has a dual temperature sensor that displays the current temperature (in real-time) and the ideal water temperature. This feature is essential because it shows you if the temperature level is safe for the inhabitants or if you need to make any adjustments.

One of the things that you need to look out for when installing a heater inside the tank is to make sure that the fish don’t get stuck close to it. As you can imagine, too much heat is not good for them. Luckily, this is not going to be a problem if you choose to go for the Fluval E Electronic Heater. This is thanks to the fact that the manufacturer has equipped the device with an integrated fish guard that protects the aquarium’s inhabitants. The fish tank heater is available in a range of wattages that are suitable for different aquarium sizes. That’s not all. You are also getting a 5-year guarantee. Therefore, you don’t have to worry about buying a new heater anytime soon. Also, the LED screen shows the temperature in both Celsius and Fahrenheit.


  • Dual temperature sensors;
  • LCD screen;
  • Fast heating technology;
  • The heater is factory calibrated;
  • Available in three power options;
  • The temperature controls are easy to reach;
  • Compact design.


  • It is not powerful enough for big fish tanks.
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4th Orlushy Submersible Aquarium Heater


  • Dimensions: 10.87 x 3.62 x 2.28 inches
  • Weight: 0.85 pounds
  • Color: Black
  • Compatible aquarium size: up to 30 gallons fish tank
  • Power: 100W
  • Temperature range: 68°F to 89°F

If you are planning to set up a large fish tank of up to 80 gallons and are searching for a reliable aquarium heater, then you can’t go wrong with the one from Orlushy that is available in the 100, 150, 200, 300, and 500 wattage options. The versatility of this device is quite impressive because it allows you to choose the ideal wattage for your tank. The temperature dial from 68 to 89 Fahrenheit allows for complete control of the aquatic climate. You can rest assured knowing that the waters your fish swim in have the right temperature for them to be healthy and happy.

The manufacturers that created this submersible aquarium heater know that keeping the water at a consistent temperature is vital, and they have equipped it with an automatic shut-off function that is enabled as soon as the ideal temperature is achieved. The build quality of the device is equally impressive being made from quartz-glass that is perfect for both saltwater and freshwater aquariums. To make things even better, the device can be placed either vertically or horizontally. You will have no problem finding a good spot to place it that doesn’t ruin the view of your aquarium and still provides proper distribution of warmth.


  • Available in five power options;
  • Ideal for aquariums of up to 80 gallons;
  • High-quality quartz glass tube (explosion-proof);
  • Automatic shut-off function;
  • Ideal for both freshwater and saltwater tanks;
  • It can be placed either vertically or horizontally;
  • 6-foot power cord;
  • Great price.


  • The heater is bulky.
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5th Orlushy Mini Aquarium Heater


  • Dimensions: 4 x 2.75 x 1.6 inches
  • Weight: 0.55 pounds
  • Color: Black
  • Compatible aquarium size: up to 10 gallons fish tank
  • Power: 50W
  • Temperature range: 65°F to 93°F

If you are just starting and you are working on a smaller fish tank that doesn’t require expensive accessories, then you are going to love the Orlushy Mini Aquarium Heater. This is easily one of the most popular aquarium heaters on the market, and it’s all thanks to the wide range of features that it offers. This is a 2-in-1 device that features a thermometer and heater as a single package. The Orlushy Mini Aquarium Heater is the perfect choice for small tanks, and it is available in the 50 and 100 wattage options. The temperature range is 63 to 94 Fahrenheit, and a LED screen displays it.

What’s great about the Orlushy Mini Aquarium Heater is that it is super easy to use. Simply set the preferred temperature, and the fish tank heater will take care of everything else. If the temperature goes higher, the heater will shut off and let it cool until it reaches the desired level. Moreover, this is a fully submersible heater, and therefore, it ships with two suction cups that help you position it safely inside the fish tank. The last thing that we want to mention about the Orlushy Mini Aquarium Heater is that the 50 watt option is best for fish tanks of 3-10 gallons, and the more powerful 100 watt option is perfect for 10-30 gallons tanks.


  • Available in two power options;
  • The best choice for small fish tanks;
  • Automatic shut-off function;
  • LED screen;
  • 2-in-1 device (it includes a thermometer);
  • Fully submersible;
  • External temperature controller;
  • Easy to use and install.


  • It’s not suitable for larger tanks.
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6th Mylivell Water Heater


  • Dimensions: 10.7 x 2.8 x 1.7 inches
  • Weight: 0.45 pounds
  • Color: Black/White
  • Compatible aquarium size: up to 20 gallons fish tank
  • Power: 50W
  • Temperature range: 65°F to 93°F

While submersible aquarium heaters are great for small to medium-sized tanks, they are not a safe option for larger aquariums. Fortunately, this is not the case for all of them. The Mylivell Water Heater is available in a wide range of power options that go up to 300 watts. Thanks to this, you can use the device for all types of tanks. Leaving the versatility of the Mylivell Water Heater aside, what makes this one of the best aquarium heaters is the fact that it is made from high-quality materials such as quarts-glass, for example. Not just that, but the device is convenient and safe to use. The manufacturer has equipped the fish tank heater with a built-in thermostat and two suction cups that make it easy to install it. We also want to note that the Mylivell Water Heater is bundled with a polarized plug that prevents electrical shock.

The Mylivell Water Heater features adjustable temperature controls between 65 to 93 Fahrenheit, and the display is easy to read. Ensuring proper distribution of warmth is essential to keeping your fish healthy, and the Mylivell Water Heater will help you do that. The aquarium heater provides a constant warm environment for the aquarium’s inhabitants, and this makes it ideal for tropical fish. What’s great about this fully submersible heater is that despite offering a plethora of features, it still sells for an affordable price tag.


  • Fully submersible;
  • Available in multiple power options;
  • It is ideal of tropical fish;
  • Adjustable temperature controls;
  • High-quality quartz glass tube (explosion-proof);
  • Ensures a proper distribution of warmth;
  • Strong suction cups;
  • Easy to install.


  • It doesn’t work very well in the vertical position.
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7th NICREW Preset Aquarium Heater


  • Dimensions: 8.2 x 3.7 x 1.6 inches
  • Weight: 0.65 pounds
  • Color: Black
  • Compatible aquarium size: up to 25 gallons fish tank
  • Power: 100W
  • Temperature range: 78°F

On the final spot, we have the NICREW Preset Aquarium Heater that offers a preset temperature of 78 Fahrenheit. The aquarium heater comes in four power options from 50 watts up to 250 watts. Therefore, it can be used for both nano fish tanks and larger aquariums that require more power. The design of the device is sleek, and it features a cool looking black and red paint job that will give your aquarium a futuristic vibe. That’s not all. The NICREW Preset Aquarium Heater is equipped with a red indicator light that lets you know when it is running or when the preset temperature has been reached.

Installing the aquarium heater is not going to take you longer than one minute. The device is attached inside glass or acrylic fish tanks with two strong grip suction cops. Talking about the installation process, we want to mention that you can mount it both horizontally or vertically. The only requirement is to make sure that the NICREW Preset Aquarium Heater is fully submerged in water so that the heat is properly distributed. In addition, the aquarium heater uses high-quality quartz glass, and it can be used in both freshwater and saltwater tanks.


  • Preset temperature control at 78 Fahrenheit (doesn’t require any adjustments);
  • Easy to install;
  • Fully submersible;
  • Recommended for 10 to 25-gallon tanks;
  • Available in four power options;
  • Red indicator light;
  • It uses shatter-resistant quartz glass;
  • Automatic safety shut-off system;
  • Budget-friendly price.


  • The temperature is not adjustable.
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Frequently Asked Questions

What is the most reliable Aquarium Heater?

The most asked question when it comes to aquarium heaters is what is the most reliable one, and there is a good reason for that. You want to make sure that the heating device you buy is powerful enough to keep the aquarium water temperature at ideal levels. While the eight products we reviewed today are all premium, we believe that the Cobalt Aquatics Flat Neo-Therm Heater is the most reliable one. The device is available in multiple wattage options, features a one-touch system, and many other useful features.

How much Electricity does an Aquarium Heater use?

This should come as no surprise, but your electricity bill is going to be a bit higher after installing an aquarium heating device. The device needs to be plugged in at all times to ensure that the water doesn’t get cold and that your fish are happy and healthy. However, aquarium heaters don’t use so much electricity that it will put a dent in your wallet. Generally, a 30-gallon tank needs to stay at around 72 Fahrenheit, and to achieve this; the fish tank heater will use about 110 kWh. This goes without saying, but larger tanks will be pricier to maintain.

Do I really need an Aquarium Heater?

Are you planning to keep tropical fish? If that is the case, then the aquarium heater needs to be at the top of your “to buy” list. The device ensures that the fish tank doesn’t get too cold and that the temperature stays at steady levels during the course of the day, even if the room cools off like during the night, for example. Another great benefit of using an aquarium heater is that you can place the tank anywhere you want in the room without having to worry if it gets enough natural light from the windows because the heater will keep the water warm.

This graphic shows the preferred water temperatures of the following pet fishes: Betta Fish, Goldfish, Neon Tetras, Mollies, Platies, Zebrafish, Guppies, Clownfish, Butterfly Fish, and Cory Catfish.

Do I need to check my Heater?

This depends on what aquarium heater you purchased. Some of them come with automatic temperature controls where you don’t need to do anything else other than to set the desired water temperature level. However, the most crucial feature that you need to look for if you don’t want to keep checking the heater is an automatic shut-off function. Heaters will sometimes overheat if left to run nonstop, and fortunately, devices such as the Orlushy Submersible Aquarium Heater will automatically stop producing heat to prevent this from happening.

Should I turn the Fish Tank Heater off at night?

Generally, fish require both periods of light and darkness. This will resemble their natural environment and keep them happy. Even though fish tank heaters are equipped either with a LED screen or light indicator, it’s not wise to turn them off during the night. The water will cool off, and this might make your fish sick. Moreover, the light the screens emit is low enough not to bother the fish, but that’s not all. There are also special aquarium heaters that use ceramic bulbs to produce only heat without emitting any light.


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