Fishes tend to be very finicky when it comes to living in a closed ecosystem. But you cannot even blame them, because they are too adorable? Nope, because their life is very delicate. And if you care for your fish, you will need to ensure that it is living it’s life to the fullest inside the water. However, it is not important that you get the best aquarium heaters, the important factor is that the aquarium heater you choose is the right one for your pet.

Aquarium Heaters do multiple wonder jobs from maintaining a healthy aquarium to thriving lives. So, we have come up with a list so that you can get the perfect aquarium heater for your fish.

Benefits of Aquarium Heaters

Sudden temperature change could shock your fish and they will be stressed. If your room temperature keeps fluctuating it will impact the aquarium water temperature as well. Hence it is important to keep the temperature at a certain level.

Depending on the types of fishes the temperature requirement will be different. Tropical fishes will require higher temperature. Whereas cold water fishes need low temperature to thrive. And even then your room temperature may not be adequate for them if you are living in a colder part of the world. There comes the importance of a good aquarium heater.

You may need an aquarium heater even if your room temperature remains at a constant level. And that is during the regular water change. Your supply water may not be at the level of your room temperature and when you mix them, the fish tank temperature will change abruptly. To overcome this situation a heater will come very handy.

Best Aquarium Heater

Best Aquarium Heaters: Comparison Table

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10 Best Aquarium Heaters Reviewed

1. Fluval E Electronic Heater – Overall Best Heater

Fluval E 300 Heater Review

The Fluval E Electronic Heater is basically a sophisticated machine that can keep you fish tank warm and fishes happy. It is an ideal heater that deserves to be picked. This 300 watt heater offers dual temperature sensors that tends to give both accurate and real time water temperature.

Not only that, Fluval E Electronic Heater also features LCD display to show temperature ranging from 68 degrees to 93 degrees Fahrenheit, you can also check them in Celsius. Moreover, it is also packed with other features that include an LCD light that switches its color display where it finds a change in temperature from preset temperature.

To add more, you can also mount the Fluval E Electronic Heater at any angle and there is a guard that surrounds the resistant glass heater core to protect the aquatic life.

  • You can adjust the temperature up to half a degree, as for instance 80.5 degree Fahrenheit.
  • Digital LCD display shows current temperature.
  • The light will warn you if the temperature is too low and high.
  • You will find the heater encased so it won’t harm your fish.
  • It has to be placed near the filter or else it starts to show No Flow error.

2. Hydor Inline – Best Inline External Heater

Hydor Inline Heater Review

To state another top quality aquarium heater, this surely comes in the list as well. The Hydor Heater is unique as it’s built in such way that you can install it in-line with an external canister filter. And this is what makes it different from other regular heaters.

If you are running a planted aquarium then it is the perfect choice for you, as it won’t be inside your tank and hamper the display.

However, with this heater you can also save some room in the tank as it would be mounted outside the aquarium. Besides, this heater features hose barbs and tautening nuts for protecting the heater on to tubing.

The setup is also easy and you will find a dial to adjust the temperature. Its red LED shows that the heater is in operating, hence it is much easy to use. Moreover, this 300 watt heater is basically ideal for both tropical and marine aquariums.

  • Easy to use.
  • You can install it in-line with an external canister filter.
  • High accuracy electronic temperature control.
  • Ideal for both tropical and marine aquariums.
  • Might impact the water flow rate.
  • Must be used with a canister filter.

3. EHEIM Jager – Best Thermostat Heater with Temperature Control

EHEIM Jager Heater

Popularity is something what Eheim Jager Aquarium Thermostat Heater seems to enjoy. It’s hype usually shows EHEIM’s sincerity towards the service. So if you are looking for a top class aquarium heater, you can consider this one for your fish. It is a fully submersible heater that needs to be placed horizontally.

However, constructed from shatter proof glass, Eheim Jager Aquarium Thermostat Heater is great for fresh or marine water. It also features thermo safety control that lets it shut the operation off after it finds water level being too low.

Not only that, Eheim Jager Aquarium Thermostat Heater also protects against running dry. Besides, its TruTemp  dial helps in regulating the water temperature while the on/off indicator light allows you to check things out.

Read our separate review on the EHEIM Jager Aquarium Thermostat Heater.

  • The red light lets you know about its operation.
  • The heater blends in well in the tank.
  • The temperature control is accurate.
  • Shuts off automatically when the water level gets too low.
  • It is quite awkwardly longer than most heaters.
  • The power cord is very thick.
  • The heater has to be placed horizontally.

4. ViaAqua – Best Submersible Heater With Break Resistant Glass

ViaAqua Heater

The best aquarium heaters are those that never disappoint you with their performance. ViaAqua heater is one of them. It is a fully submersible heater that features break resistant glass.

Besides, it comes with a built in thermostat that regulate the temperature of water automatically.

Its readouts are much visible with red number. Not only that, you will also find it very easy to setup with the suction cups that come with the heater.

They deserve all the praise for handling fish tank with volumes ranging from 30 to 80 gallons. However, just like other heaters, this too is suitable for fresh and saltwater aquariums.

  • Great quality glass and plastic used.
  • The temperature reading is very clear and big.
  • Fully adjustable temperature control.
  • Does the job effectively.
  • There isn’t any protection for the glass on tube’s end.
  • You might find it bulky in appearance.

5. Cobalt Aquatics Neo Therm Heater – Best Heater For Nano Tanks

Cobalt Aquatics Neo-Therm Pro Aquarium Heaters_Multiple Sizes

While most of the aquarium heaters are presenting themselves with boring designs, Cobalt Aquatics Neo Therm Heater has come with innovative thoughts regarding this. Popular for its perfection, Neo-Therm is surely something that has the capacity to steal your attention.

This 25 watt Neo Therm Heater features thermal protection circuitry and a shatterproof glass as well so that you don’t have to worry about the glass getting cracked. Moreover, starting from its installation to its usage, you will find it pretty easy breezy.

Besides, it features one touch system allowing you to set your preferred temperature to let your fish play in the water. So, if you want one for your fish, this can be the best fish tank heater for it.

  • Keeps the water at the perfect temperature.
  • Nifty bracket system.
  • Easy to read LED display.
  • Comes in unique design.
  • Might fluctuate if you live in cold region.
  • You might find it long.

6. Finnex Aquarium Heater

Finnex Aquarium Heater

This is another high quality aquarium heater that you will find in the market. The Finnex Aquairum Heater is an Electronic controller Aquarium heater that offers a stable and accurate temperature for your fish and the tank.

It delivers precise temperature readouts ranging of +/-2. Not only that, this best heater comes with corrosion resistant titanium tubes that you will find shatterproof and great for use both in saltwater and freshwater tanks.

The tubes will be heating fast and they are also easy to hide since they appear small in size. Moreover, it also consists of an LED indicator so that you can know if the heater is working efficiently or not.

And the best thing is that it uses modern development to offer precise digital control so that it can keep the temperature at a continual level.

  • Uses modern development to offer precise digital control.
  • Delivers precise temperature readouts.
  • Features fast corrosion resistant titanium tubes.
  • Comes with an LED indicator.
  • Might not shut off automatically.
  • The material might feel cheap.

7. Marineland Precision Heater

Marineland Precision Heater

Marineland needs no introduction as they are known for providing their best products all over the world. As for this product, this is also one of the high quality aquarium heaters that needs the highlight.

This is a 300 watt heater that comes with adjustable temperature dial allowing you to preset the temperature 1 degree with each click. Besides, it provides thermal switch that shuts automatically off as the temperature goes above the preset and gets on when it cools down.

To add more, the heater offers a mesh heating element consisting of a mica core for ultra-heat transmission. This does not end here, it comes with a built in mounting bracket that attaches to the glass tightly.

And the heater delivers three window positions so that you can see the temperature display. Moreover, its sliding scale can tell the accurate temperature setting while the dial shows it from other location. It comes with very good quality suction cups.

  • Provides accurate temperature.
  • The temperature dial is adjustable.
  • Provides thermal switch.
  • Offers amazing suction cups.
  • Might disappoint you for its durability.

8. Penn Plax Aquarium Heater

Penn Plax Aquarium Heater

If you are still looking for more options for the best fish tank heater, here is another one. This 200 watt heater from Penn Plax tends to set and maintain the temperature in the aquarium within 1 degree precision. So you can actually enjoy your fish swimming healthily and happily.

Moreover, the heater contains both Celsius and Fahrenheit temperature so that you can read the one according to your convenience. This is a full submersible heater so you can place it in the tank horizontally or vertically, the choice is completely yours.

However, it features a preset temperatures to 76 degree Fahrenheit but you can also program it the way you want.

  • Very efficient heater.
  • Provides accurate temperature.
  • You can read the temperature in both Celsius and Fahrenheit degrees.
  • Comes with an Indicator light.
  • You can place it both horizontally and vertically.
  • The power cord is not very long.

9. Aqueon Pro Adjustable Heater

Aqueon Pro Heater

Aqueon is a brand that most of the aquarists would recommend you. It does not only come with ‘like a pro’ attitude but has the ability to impress you quite much. The best thing about this aquarium heater is that it weighs pretty light with 14 ounces.

Besides, this is a 200 watt heater that owns electronic thermostat to help give you accurate temperature readouts for the fish tank. Because you will never want to fry your fish with overheating the water, will you?

However, another great thing about this heater is its power light monitor. You can get to know when the water reaches the preset temperature and when the heater is turned on. Not only the product is shatterproof but will keep your fishes all warm and welcome.

  • Heat is seen to distribute over a greater area of the tube.
  • Ability to mount both horizontally and vertically.
  • The glass is durable and shatterproof.
  • Power light monitor makes the monitoring easy.
  • The temperature markings around the thermostat dial might not be accurate.

10. Tetra HT Submersible Aquarium Heater

This is another one of the best aquarium heaters that you can buy for your little fishes. The Tetra HT is a submersible aquarium heater that has indicator lights so that you can know if the heater is on. With this, you can keep yourself safe as people get burnt easily for touching the hot heater while it is on.

Besides this, the light also lets you know the time when it reaches the preset temperature. So, the red light shows the heater is doing the job while the green light shows that it has done its operation. To talk about the best part of the heater, it comes with an electronic thermostat. It will help maintain the water at 78 degree Fahrenheit so that the heater does not fry your little tropical pets.

  • Since it is submersible, you can place it the way you want.
  • Comes with electronic thermostat.
  • There is an indicator light for important notification.
  • Comes small in size.
  • Operates at only one temperature.

Types of Aquarium Heaters

1. Submersible Heaters

These are the fish tank heaters that are needed to be submerged right down in the water. As they are placed in the water, they are quite effective in heating the water. You must ensure that there’s enough room left surrounding the heater so that it can give your fish a space to swim freely. Moreover, this kind of aquarium heaters should not touch the glass as it can crack the glass.


  • Can be placed at any angle: The best thing about submersible heater is that you can place them horizontally, vertically or any angle you like since they are fully submersible.
  • Internal thermostat to the rescue: Many of the submersible aquarium heaters have internal thermostat, so if you place the heater fairly low with horizontal position, it will help the thermostat receive an accurate readouts on tank temperature.


  • Always on display: The worst part of submersible fish tank heaters are that they are need to be place right inside the tank. It does not only look awful but also obstruct the life of fish.
  • Overheating: Submersible aquarium heater can heat your tank inefficiently as they stay inside the water leading the water to be the hottest.
  • Plug and Unplugging: Having a submersible heater can also feel like a hassle since it needs to be switched off after every water change.

2. Immersible Heaters

Call it Immersible or hanging heater, this is basically used to hang over the aquarium with the glass tube that accommodates the heating element to immerse in water. The immersible fish tank heaters are known as quiet heaters and they are the best for new aquarist.

However, it is important that you make sure that this kind of heater is properly secured because it can electrocute your little pet and even end up stating a fire. The immersible aquarium heater is never ideal for brackish or marine aquariums, hence it is better to not select one of you own either of the tanks.


  • Least Expensive: You will find Immersible aquarium heaters more pocket friendly than most of other types.
  • Quiet: This kind of heaters do their operation with all the silence, hence they are quite a quiet piece.
  • Ideal for new aquarists: It is a great heater for those are new in the hobby since it helps them maintain correct water temperature.


  • Not perfect for all: Hang on heaters are hazardous for marine or brackish aquariums.

3. Inline Heaters

Basically known as external heaters, the Inline involved either a sump or a filter. You can place one in the line between the aquarium and the sump or filter’s return pump. They are an ideal pick for bigger tanks and also block contact between the heater and the fish.


  • Hidden from view: The best thing about inline aquarium heater is that you can place them externally unlike submersible heater that needs their placement inside the tank. And it is completely understandable how awful it look. However, as the inline heaters are placed outside, so all you are left with is, enjoying your fish swimming around freely.
  • Even and Accurate heating: As the heater is kept outside the tank, water from such heaters flows back to the aquarium following to circulation and equal distribution of the heat.
  • Never unplug again: You can keep the inline heater running while you do a water change.


  • Over costly: The worst part of inline aquarium heaters are that they are twice as expensive as other heaters. Though the price is absolutely justifiable considering their features and benefits.
  • No water flow, no heat: If your canister or sump filter is somehow turned off or if it fails, the water will not pump through the heater. And the water temperature of the tank will get dropped till the flow returns.
  • Risk of leaks: If you do not install the inline heater correctly, there will be risks of leaks of heater. Hence, you must be careful while installing the heater.

4. Substrate Heaters

Although these are not very common and usually features wires as the heating element that are concealed under the gravel. They are basically suitable for plant fish tanks.


  • Good for planted tanks: This kind of heaters are ideal for planted tanks where the gravel acts as an insulator for keeping the roots of the plants cool.
  • Even heating: The substrate heaters tend to distribute heat in the water evenly which makes the environment good for the fishes.
  • Encourage plant growth: The substrate heaters promote plant growth that help in growing the plant inside the tank.


  • Installation Hassel: The worst part of substrate heater is that you need to tear the whole tank down just to install the heater.

Buying The Best Aquarium Heaters: Factors to Consider

Size matters

The size of aquarium heaters depend on the tank sizes mostly. If you want to calculate the ideal size, you need to subtract the existing room temperature from the required one. With this, you can determine the ideal size. As for instance, a 25 watt heater is ideal for 5 gallon tank whereas a 50 watt is for 10 gallon tank.

Type of Heaters

Different heaters serve different purpose. So ensure that the type you take goes along with your fish, aquarium type and budget.


You should definitely choose the one that comes in your budget. Since there are a variety of heaters available in different price, you should take the one that is giving the best service.

If your budget is somehow tight, immersible heater can be an ideal option for you or else you can take inline heaters if you add some more money.

Easy to maintain

You should always keep in mind that the heater you select for your fish is easy to clean and  maintain.

Though most of the heaters comes with a built-in controller it is safer to install an external heater controller for your aquarium.

Best Fish Tank Heater: Editor’s Pick

When it comes to saying a certain heater is the best, lots of consideration goes into it. The models we analyzed above have most of the qualities which would make you call them as the best.

These heaters are from trusted manufacturers and tested by users over the years. So there should be no doubt about the performance, durability, safety factor and heating capacity with precision.

Though obviously all of them are great, we pick the Fluval E Advanced electronic heater. It is thoroughly tested by aquarists over the years for it’s excellent heating with precision as well as durability.

If you are considering a good heater for your small or nano tank then go for the Cobalt Aquatics Neo-Therm Heater.

How to Install Aquarium Heater

Most of the aquarium heaters nowadays are plug-&-play. Whatever the model you choose, the installation process will be roughly same as the following steps –

  • Check the instrument thoroughly after unpacking. You need to make sure that the protective casing is not compromised, no visible sign of damage on the heating unit and no wires are exposed.
  • Find a suitable spot to attach the heater inside your tank if it is a submersible heater. If you can place it behind the decorations, rocks or plants it won’t be visible and the beauty of the tank won’t be hampered. Clear the glass surface if there is any algae or anything so that the heater is attached tightly.
  • Suction cups provided by the manufacturer are usually of good quality, use them instead of using other alternatives. Make sure the heater doesn’t come to contact with any decorations or plants in your tank. Suction cups ensure separation from the aquarium glass as well.
  • After installation keep the heater inside your tank for at least 30 minutes before turning it on so that the surface temperature adjusts with the water temperature. This will save you from any crack of the glass surface due to sudden temperature change.
  • It is advisable to use an external thermometer to check the initial water temperature and also adjust/calibrate the temperature reading from the heater. There could be a slight error. Also place the external thermometer from the heater as far as possible so that you can ensure the whole water body is evenly heating up.
  • Now turn on the heater and set your desired temperature.
  • Keep the heater on operation and check water temperature every 6 hours from external thermometer as well as from the builtin thermometer of the heater. Make sure your heater setting is calibrated rightly and the desired temperature is achieved.
  • Last but not the least, monitor your fishes closely to detect any abrupt behavioral change due to temperature adjustment and take measures accordingly.

Where to Place the Heater

It is usually a bad idea to put the heater in stagnant water. The heater should be placed near the out flow of your filter to evenly distribute the temperature through out the tank. You can use a power head near the heater to increase water flow in the tank.

Also if you have decorations, rocks or plants it would be easier for you to hide the heater. If the heater inside the tank bothers you much then you can go for a inline heater which will be placed out of your eyesight.

Electricity Requirement and Capacity of Aquarium Heater

A heater is not some occasional item that you use rarely. Rather it will be plugged in and operating almost always. So the electricity requirement should be carefully considered as it surely will ad up to your electricity bill. Hence selecting the right heater for your tank dimension and fish requirement is very important.

As you can predict, larger tank requires more electricity to heat it up. A general rule of thumb is you need one watt per gallon of water. To be in the safe side select the heater rated for slightly higher capacity than your tank. Also if you are keeping tropical fishes you will need more temperature than goldfish. As goldfish is cold water species.

Usually, a 30-gallon tank will consume approximately 110 kWh of electricity per year to heat it at 72 Fahrenheit (22 degree Celsius). You can take this as reference and calculate the electricity requirement for your tank or heater.

Also in the same tank if your fishes requirement is 82 Fahrenheit or 28 degree Celsius then the power consumption per year would be 440 kWh, that means four times higher!

It is not possible to give you an exact number of your electricity bill increase due to the heater but from the above example you can make an educated guess.

Selecting the heater with right rating is very crucial. Here is a reference you can use to determine what capacity of heater you should install.

Size of Fish TankWattage rating of the heater to increase 5FWattage rating of the heater to increase 10FWattage rating of the heater to increase 15F
5 Gallon505050
10 Gallon5050100
20 Gallon50100100
30 Gallon100100150
55 Gallon150150200
75 Gallon200200250
90 Gallon200250250

Frequently Asked Questions

What is the ideal temperature for Betta fishes to live a healthy life in the tank?

The ideal temperature ranges from 75F to 82F (which is about 23.88 degree Celsius to 27.77 degree Celsius). As Betta fishes are tropical fish, you should always ensure that the temperature does not drop below 74F. If you live in warmer places, you can avoid having heater, or else you will certainly need one if the region has winter seasons.

How do tank heaters work?

The heater is usually used for temperature that needs to be controlled by thermostat. You will find an adjustable dial with each heater so that you can preset the temperature for the tank.

How would you understand if the aquarium heater is on?

Almost all the heaters come with an LED light system on LCD display so when you turn the heater on and when it starts to operate, it will light up indicating that it is heating the water.


The well-being of your fish should always come first when it comes to buying heater. On the basis of the list given, you can have the one that will be perfect for your fish. Not only that, you should also make sure that heater is not only about buying and installing it, you also have to maintain it so that the life of your fish can stay safe for longer time.

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