Best Aquarium Heaters For Small And Large Tanks – Reviews 2022

Last Updated on December 5, 2022 by Vernon Scott

When we think of heaters, we do not always think of the many different heater types that are needed. When readers started to ask us what the best aquarium heaters were, we made a conscious effort to find this information out.

We went to pet stores and asked them if they would try out some aquarium heaters and report to us which ones they would buy for their own personal use. The heaters vary in style and application, but the ones we have listed are the ones that got the best reviews for being effective, easy to operate, and safe for the fish that live in the aquarium. 

Best aquarium heater 2022 Reviews

1. Cobalt Aquatics Flat Neo-Therm Heater

Cobalt Aquatics Flat Neo-Therm Heater

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Cobalt Aquatics Flat Neo-Therm heater is a fully submersible heating unit that has an adjustable thermostat so you can keep the water in your tank at a temperature that is closer to the normal temperature the fish you raise would live in in the wild.

The temperature can be set between 66 and 960 F. You only have to push one button to set the temperature and then the water in the tank will stay within 0.50 F of your choice.

The LED display will show you what temperature you have set the device to keep and what temperature the water actually is inside the unit.

This is a safe and reliable device. If you forget to turn the water off on a warm day the heater will automatically shut-off to prevent an overheating situation that could damage your fish.

It is designed with a shatterproof outer casing made of thermoplastic materials. That thermoplastic material eliminates the possibility of the heater shattering inside the tank.

It is designed with a holster or bracket that can be positioned so the heater faces outward or inward. It is efficient and can be purchased in a variety of sizes so you always get the heater that is the right fit for your aquarium.

2. Hydor In-Line External Heater

Hydor In-Line External Heater

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Hydor In-line external heater for aquariums can be used for freshwater aquariums or salt-water aquariums.

It is an in-line device so it does not submerge in the water of the tank and it is not going to cause any concerns of shock or shattering inside the tank.

It is safer around the aquatic life-forms living in your tank because they never come into contact with the device or any connections to the device. Aggressive fish cannot damage the heating unit.

This device is a 300=watt unit and can warm the water required in a 125-gallon aquarium. It has precision temperature controls that allow you to establish the exact temperature you need or want, the water to be kept.

It warms the water after it flows through the filter and before it is placed back in the tank.

This heater is super simple to set-up. It is low maintenance and does not use a lot of electricity or energy to operate it. You set it up on the backside of the aquarium behind the glass so you do not see it when you are looking into the tank and it does not interfere with your tank décor.

3. JBJ True Temp Titanium Heating System Kit for Aquariums

 JBJ True Temp Titanium Heating System Kit for Aquariums

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JBJ True Temp Titanium heating system kit for aquariums is one of the most complex heating units designed for this purpose.

It has a large LED display that shows the current temperature of the water inside the tank.

It has a remote temperature probe that goes inside the tank to keep a record of the water inside and the main heating unit is established outside of the tank.

Everything you need to establish this heater in your aquarium is included in the kit. You get the magnets you need to hold the heater in position, the sensor that detects the water temperature and the control unit you use to set your preferred temperature and see the LED display of the current temperature.

This unit is designed to be used with larger aquariums of 100-gallons or greater. It is slightly more expensive than some of the other heater styles, but it is also extremely safe for the fish, it will not shatter or overheat, and aggressive species of fish cannot damage the unit.

The heater is very easy to install and it requires little to no maintenance to keep it functioning properly. 

4. Tetra HT submersible aquarium heater

Tetra HT Submersible Aquarium Heater

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It has an electronic thermostat maintains the water temperature inside the tank at a constant 780 F. This is the ideal temperature for the majority of all tropical fish species.

The indicator light on the unit allows you to know when it is working. The light glows green when the heater is on and it is red when the heater is off.

This is an energy-efficient device because it powers off when the temperature reaches 780 F and doe not run continuously.

This heater is not fashioned from glass so it is not a danger of shattering. It is submersible so the positioning in the tank can be horizontal or you can place it vertically. It is small and very easy to conceal using the plants and decorative items inside the tank.

You can use this heater in an aquarium that ranges between the 2-gallon and 10-gallon size. You simply place the heater into the aquarium and position it as you like it and then you plug the cord into the electrical outlet.

Always unplug the device prior to putting your hands into the water for aquarium cleaning or maintenance.

5. Fluval E Electronic heater

Fluval E Electronic heater

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This is capable of being submerged to a 39-inch level. You position the heater on the side of the tank but do not hang the heater by the cord and do not lay the heater on the bottom of the tank.

It is designed to be used in larger aquariums and is a 300-watt appliance. There is an LCD screen on the front of the device that tells you the current temperature.

The mounting bracket that comes with the unit will allow you flexibility in the angle and position of the unit. 

You can establish it so it is easy for you to see the LCD screen and determine if your tank is properly heated. It has a fish guard designed onto it so your fish cannot come into contact with the actual heater.

It also has a protective glass sleeve that prevents larger and more aggressive fish species from damaging the heater or damaging themselves by coming into contact with the heater.

The device is slim and unobtrusive. It will not distract your eye from the beauty of your aquarium, and most of the time you will not notice the unit unless you are specifically looking for it to determine the temperature of your tank.

6. Eheim Jager Aquarium Thermostat Heater

 Eheim Jager Aquarium Thermostat Heater

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The Eheim Jager heater is a fully submersible device. It can be positioned anywhere along the vertical sides of the tank or completely at the bottom of the tank.

If it is mounted vertically along the sides of the tank and the water level inside the aquarium dips too low the heater will automatically shut off to prevent damage.

This heater does have a glass tube protecting it from the fish and water, and protecting the fish from it.

The glass is specialized and shatter-proof so you do not have to worry about breakage inside the aquarium. The thermostat allows you to maintain proper temperature regulation so the water is never too hot or too cold for the aquatic life inside it.

It has a simple indicator light that will tell you at a glance if the unit is turned on or turned off. Be sure to unplug the unit before installing it back into the aquarium after cleaning or maintenance. Always unplug the unit when you are caring for the tank.

You are able to use this device in fresh-water units and in salt-water aquariums. It has an extra-long power cord attached so it is easy to position.

7. ViaAqua 300 Watt Titanium Heater

ViaAqua 300 Watt Titanium Heater

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ViaAqua titanium heater is perfect for aquariums up to about 80-gallons. It has an easy to see and read LCD display on the controller.

There is a remote sensor that goes into your aquarium and it is designed with automatic shut-off technology so it does not overheat and protects itself and your tank inhabitants.

The remote sensor is better in large aquariums because the sensor is positioned away from the heater and you learn the true temperature of the entire aquarium.

Heaters without remote sensors simply tell you what the temperature is close to the heater itself. The sensor comes into contact with the water but the controller to the heater never comes into contact with the fluid contents.

You can set this heater to display the temperature in Celsius or Fahrenheit according to which you prefer. This is accomplished by pressing the hold button on the device and holding it down for three to four seconds.

The device is easy to install. You should install the sensor and position the controller on the outside of the aquarium prior to plugging the device into the electrical outlet.

You do not have any maintenance concerns with this device, and aquatic creatures cannot come into contact with any portion of the device that could cause them any harm.

8. Hygger 500W 300W Aquarium Heater

Hygger 500W 300W Aquarium Heater

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The Hugger aquarium heater is a submersible heating appliance that quickly warms the water in a 60-gallon to 120-gallon aquarium.

It has a six-foot power cord so it gives you ample room to establish the heater in different locations. 

This device is safe for your pets. The tube is a quartz material combined with plastic components so you do not have concerns about shattering, or about toxicity. 

It is slim and the portion of the unit that goes inside the tank can easily be hidden behind aquarium plants and decorative items. It does not distract from the beauty of your aquarium.

This heater is very quiet while it is operating so it will not distract you. It has an LED display showing the current temperature of the water. It has indicator lights that let you know when it is powered on and when it is powered off.

There is no maintenance needed to keep the unit functioning properly. When you are cleaning the tank unplug the device and controller before you empty the water from the tank.

When you replace it after cleaning put the sensor inside the tank and fill the tank with water before you plug the heater back into the wall socket.

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How to choose the best heater for the aquarium? 

If you have an aquarium you want to get the best heater for your tank of fish. You need something that fits perfectly and will not overheat your water. You also need something that is low maintenance and easy to use.

To help you select the best heater option for the type of tank you have to consider the following features and styles. Then when you are comparing heaters you can find the features that you know you want and need.


The size of your aquarium is the first determining factor in what wattage heater you will need. For a good estimate, you can consider about 5 watts for every 10-gallons of water.

You also have to consider the degree that the water has to be heated. To get this figure you take the temperature of the room and the temperature that you may want the water to be and deduct the room temp from the preferred water temp.

Heater Styles


The submersible heaters can be placed horizontally under the water in the tank. The entire heater unit can be submerged under the water. These heaters are less obtrusive and they do not interfere with your ability to watch the fish in the tank.

If these heaters overheat the glass can crack. You should consider the tough plastic heaters if you choose a submersible.

Hanging Heaters

These heaters are designed to hand from the side of the aquarium with a portion of the heater being submerged into the water. They are less expensive than the fully submersible heaters are and they are easy to use.

These heaters require your tank hood to have a hole in it that allows the heater hanger to hang on the side of the tank. They are not as effective as the submersible heaters are.

Substrate heaters

These are wires, that affix to the base of the aquarium. They are one of the most expensive styles of aquarium heaters.

In-Line Heaters

These heaters are fitted between the sump pump and they heat the water before it is put back into the tank. It will be made of heavy-duty plastic and it is ideal if you have a species of large fish that are very aggressive in the tank. They are expensive and they tend to create more leak situations outside the tank than other styles do.

Filter Heaters

As the water passes through the filter it is warmed. These heaters are also expensive and usually only found in larger sizes.

Frequently Asked Questions

1. Where to place the aquarium a heater

The heater needs to be positioned in close proximity to the filter inlet or to the pump that circulates the water. This positioning allows the heated water to be evenly distributed so there are no hot spots in the tank where the water is a good bit warmer than it is in other portions of the tank.

2. How to tell if the aquarium heater is broken

The quickest way to evaluate the aquarium heater is to place your hand in the water. Slowly move your hand in the direction of the heater. When your hand gets close to the heater you should be able to feel the warmth being emitted by the unit.

3. What size heater for an aquarium is ideal?

The ideal aquarium heater is probably the 100 watt or 200-watt unit. This is true if the aquarium you have holds 50 to 200 gallons of water. If you have a smaller aquarium then the heater size will need to be smaller. If you have a five-gallon aquarium you need at least a 25-watt heater.

4. How to install an aquarium heater

If you have purchased a submersible heater then you can install it horizontally close to the bottom of the tank. Normally there is a small suction cup that the heater attaches to and the suction side attaches to the glass of the aquarium.

Some heaters are not fully submersible and these units will have a clip that allows them to hang from the side of the aquarium into the water of the tank.

5. How to use an aquarium heater

When you first introduce the heater to your tank you do not want to set it on the optimum temperature and let the water heat all at one time. You want to adjust the heater so it warms the water to one or two degrees above the temperature of the water.

Then each day you will increase the temperature by one or two degrees allowing the water to warm gradually and the fish to acclimate to the change in temperature slowly.

6. How do I know if my aquarium heater is working?

If you place your hand in the water near the heater you should be able to feel the warmth from the unit. You should have a thermometer in the tank that tells you the precise temperature of the water and if the heater is working the temperature will remain about the same, and if the heater stops working the temperature will drop.

Aquarium size and heater Guide

Aquariums hold different amounts of water so the heaters made for these items are designed in different sizes. If the heater you have is too small it will not adequately keep the water at the right temperature.

Even if it can get the water to the right temperature the heater will have to work too hard and will not last as long. On the other hand, if the heater is too large it will overheat the water quickly.

Heating requirements according to tank size

  • 5 – 10-gallon tanks need a heater that is between 25 and 75-watts
  • 20 – 25-gallon tanks need a heater that is between 50 and 200 watts
  • 40 – 50-gallon tanks need a heater that is between 100 and 400 watts
  • 65-75-gallon tanks need a heater that is between 200 and 600 watts

Most people who have an aquarium that is up to a 200-gallon aquarium will use a submersible heating unit that produces between 100-watts and 200-watts.

Some people choose to augment the heat in their aquarium through the use of standard lightbulbs in their aquarium hoods. This method is very hard to regulate and will often make you have water in your tank that is too hot for your fish.

To determine the size of the heater that you need you to have to look at the average temperature in your home and calculate the difference in degrees between the ambient air temperature and the temperature you want the water to be kept at.

If you normally keep the room at 72 degrees and you want the water in the tank to be 78 degrees then you need to heat the water to 6 degrees to achieve this temperature.

Tank Size

Increase heat by bellow 10 Deg.

Increase heat by 10 – 15 Degrees

Increase heat by 15 degrees F





10 gallon-20-gallon















200-watt x 2




250-watt x 2




300-watt x 2

When getting a heater for your tank consider the length of the heater tube. The heater tube should not be longer than the height of your tank. Sometimes you may have to have multiple heaters to maintain the temperature properly in large tanks, or in tanks where the temperature variation between water temperature and room temperature is greater than 10 degrees F.

Final Note

The best aquarium heaters are determined by your needs, the size of your aquarium and your preference in style.

If you are looking for a submersible heater Cobalt Aquatics Flat Neo-Therm heater is a fully submersible heating unit and it has an adjustable thermostat that will allow you to have more control over the temperature in your tank.

If you would prefer to have a heater that has a remote sensor the ViaAqua 300-watt titanium heater is a heater that deserves your consideration.

Vernon Scott

Vernon is the founder of this cool ( read HOT! ) website. He's superbly experienced on heating technologies as well as having clear ideas about modern heating appliances. Vernon has called him " I am a hot ( this time read COOL! ) guy!"

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