Best Aquarium Heaters on Test

So you’re looking for a heater for your fish tank. Where do you even start the search, bearing in mind how many different models there are on the market? How do you figure out which will work for your current (or planned setup)? And most importantly of all, what is the best aquarium heater currently on the market?

That’s exactly what we’ll be covering in this guide. By the end you should be an aquarium heater expert, ready to choose the perfect model for your needs. Let’s get started!

In a Hurry? Check Out Our Top 3 Aquarium Heaters

1Hygger Titanium Heater

4.5 out of 5 stars (4.5 / 5)Check Pricing
2Fluval E Electronic Heater

4.5 out of 5 stars (4.5 / 5)Check Pricing
3EHEIM Jager TruTemp Submersible Heater

4 out of 5 stars (4 / 5)Check Pricing

Features to Look out For in the Best Aquarium Heaters

Sadly, choosing the perfect aquarium heater isn’t just a matter of selecting one off a list; you also need to be certain it will do the job necessary. So what should you check before handing over your hard-earned cash?


The wattage of the heater determines how well or how quickly it can heat the water and if it can maintain the required temperature or not. Depending on the room temperature and the climate at your location, it will take 2.5 to 5 watts to heat a gallon of water.

Keep in mind that you’re not raising the temperature of the water in the aquarium from zero degrees to the required temperature. Your aquarium water should already be close to room temperature. So, you subtract the room temperature from the required temperature and you arrive at the number of degrees you need to raise the temperature of the water by.

For example, if the room temperature is 60 degrees Fahrenheit and you need it to be 78 degrees Fahrenheit, then you need a 12 degree rise in temperature. Also, if the aquarium is larger than 20 gallons, it makes sense to use two smaller heaters instead of one powerful heater. It will ensure the temperature inside the aquarium remains stable and uniform.


The species of fish you have will dictate the size of the aquarium as well as the ideal water temperature. The size of the aquarium and the volume of water in it determines the wattage of the heater. But the size of the heater itself needs to be factored in as well. Do you want it to be visible inside the tank or do you prefer the heater to be hidden out of sight?

Heating Technique

There are several types of heaters. The primary difference between them is the technique each employs to heat the water. So, immersible heaters or hanging heaters can be dipped into the water from above. These do a decent job in smaller aquariums and cost less as well, but in bigger aquariums immersible heaters do not provide uniform and stable heating.

Submersible heaters are the most common. These typically sit at the bottom of the aquarium and near the filter. These provide much more stable heating.

In-line heaters are another possible option. In-line heaters sit in the space between the filter and the sump and heat the water as it re-enters the aquarium. However, these are quite expensive and since a part of the heater is kept outside the aquarium, there’s a chance of leakage. You can also get filter heaters, i.e., filters with an in-built heater.

Access and Temperature Control

Access is a key issue that you should take into consideration while making your selection. Once the heater is fitted underwater, you want to have easy access to the controllers or else you will end up fidgeting underwater, trying to make certain adjustments.

The other factor to consider is if the heater has the option of temperature control. Unless you live in a place with warm weather all year long, the temperature will change with the changing seasons and you will have to adjust the temperature of the heater or else the water will either overheat or become colder than optimal.

Finally, make sure that the heater has a temperature gauge and that it’s clearly visible underwater. You could and probably should have a thermometer as well, but a temperature gauge really helps.


Cost is an important factor.

Maybe you want to splurge on your aquarium and don’t want to pay too much for the heater. Maybe you’ve a fixed budget or maybe you just want the best that money can buy.

Buying a heater from a well-known brand makes more sense, because you will get a better product and after sales service, but it will cost more than a heater from a less well-known brand.


Safety features are extremely important and it cannot be emphasized enough. The heater you select should have an indicator to inform you when it’s on and when it’s off.

It should also have a protective guard of some sort, because you don’t want the fish to come in contact accidentally.

The other key feature is auto switch off and restart. You want the temperature to remain stable to create the right environment for the fish. What you don’t want is overheating or the temperature dropping too low. So, the auto off and restart feature is crucial.

Detailed Reviews of the Best Aquarium Heaters

Hygger Titanium Heater: Top Quality Heater with Precise Temperature Control

The Hygger Titanium heater is a more premium heater model. It is available in three versions. The 50-watt version can be used in aquariums between 5 and 10 gallons, the 100-watt version can be used in aquariums between 10 and 25 gallons and the 200-watt version can be used in aquariums between 20 and 45 gallons.

The kit includes a digital temperature controller and a thermometer, besides the heater.

Similar to the other Hygger heater discussed below, it needs to be fully submerged in the aquarium and fixed in place using the twin suction cups. The thermometer needs to be submerged as well, but placed in the opposite end of the aquarium.

Connect the temperature controller to the heater before placing it in the aquarium. The controller has mounting holes at the back so that it can be hung on a wall.

You can set the temperature in either Fahrenheit or Centigrade via the controller. The LED display on the controller will show both the current water temperature and the set temperature, so that you can keep track.

You can set the temperature between 32 degrees Fahrenheit and 104 degrees Fahrenheit. Once the set temperature is reached, the heater will turn off automatically and will restart when the temperature drops by 1 degree Fahrenheit.


  • You get the heater plus a digital controller and a thermometer.
  • Offers wide range of temperature settings and so can be used with a variety of underwater species.
  • Lets you control temperature precisely and the digital display shows both current temperature and set temperature.
  • Maintains stable temperature.


  • Some users have complained that the suction cups slip down over time.
  • The price is on the higher end.

4.5 out of 5 stars (4.5 / 5)

Fluval E Electronic Heater: Real-time Temperature Control and High on Safety

The Fluval E electronic heater is particularly good at maintaining a stable temperature inside the aquarium. This fully submersible heater is equipped with dual temperature sensors that keep a real-time track of water temperature to ensure that the underwater environment is optimal for the fish.

Related:  How to Lower pH in an Aquarium or Fish Tank

You can see the water temperature on the LCD display in Fahrenheit and Celsius. If the water temperature rises or drops by 2 degrees Fahrenheit or more from the set temperature, the display changes color.

If the change in temperature is 5.5 degrees Fahrenheit or more, the display starts flashing to indicate a potential risk.

This heater is available in four versions or sizes. The 50-watt version is for aquariums up to 15 gallons, the 100-watt version is for aquariums up to 30 gallons, the 200-watt versions is suitable for aquariums up to 65 gallons and the 300-watt version is ideal for aquariums up to 100 gallons.

While installing the heater make sure that it’s placed towards the rear end of the aquarium and close to the filter. It should be immersed at the very least till the minimum water level indicated, though ideally it should be fully underwater. This is because once the water level goes below the minimum mark, the thermostat fails to read the water temperature and thus fails to control the heating.

The Fluval E has a Low-Flow indicator. So, if you see LF on the display it means that the heater needs to be placed in an area that has higher water circulation.

It is also equipped with a fish guard, which ensures that fish do not come in contact with the core of the heater and hurt themselves.


  • The colored display alert system is very useful. It’s not always possible to be in close proximity to the aquarium and check the water temperature. Change in display color and/or flashing of the display is a more effective alert. This is powered by Vue Tech technology.
  • It’s digital microprocessor sensors ensure that water temperature is read with precision.
  • The protective guard on the heater ensures the fish aren’t hurt and there are no accidents.


  • The Low-Flow indicator can cause a bit on a nuisance at times and even placing it right next to the filter doesn’t change the LF sign on the display. If the aquarium doesn’t have a filter with a high current, this can be an issue. On the other hand, high current isn’t suitable for tropical fish like bettas.

4.5 out of 5 stars (4.5 / 5)

EHEIM Jager TruTemp Submersible Heater: Precise Temperature Settings and Great Safety Features

The EHEIM Jager TruTemp submersible heater is one of the best electric heaters in the market. It can be used in both freshwater and saltwater aquariums and sports a shatterproof construction. It can also withstand major fluctuations in temperature, which makes it a safe heater.

The company says that it offers precise temperature setting with a difference of -/+ 0.5 degrees Celsius. You can set the water temperature between 65 and 93 degrees Fahrenheit.

The heater has an on/off indicator light, which informs you when the heater is functioning and when it’s switched off, so you don’t to come in close to check. It also automatically switches off when the water level goes below a certain level.

It’s available in 8 versions or sizes, including 25 watts, 50 watts, 75 watts, 100 watts, 125 watts, 150 watts, 200 watts, 250 watts and 300 watts.


  • It allows you set water temperature accurately and maintains a stable temperature after that.
  • It’s available in a number of sizes and can be used in most types of aquariums.
  • It has quite a few safety features in place, which is great.


  • Some users have complained that the recalibration ring on the TruTemp dial doesn’t always work as well as the manufacturer claims.

4 out of 5 stars (4 / 5)

Hygger Submersible Heater: Big on Safety and Offers Excellent Temperature Control

The Hygger Submersible Heater is available in three versions. The 50-watt version is suitable for fish tanks between 5 and 10 gallons, the 100-watt version is suitable for fish tanks between 10 and 30 gallons and the 300-watt version is suitable for fish tanks between 30 and 60 gallons. It can be used in both saltwater and freshwater aquariums.

It’s made of durable quartz material, which the company claims is explosion-proof and shatter resistant.

The heater is equipped with two suction cups that need to be used to stick the heater horizontally on the inside surface of the fish tank. Make sure that it’s completely submerged and secured via the suction cups. Do not place it vertically or obliquely in the fish tank and make sure it isn’t partly submerged either.

The company advises you to not use this in an aquarium with turtles in it, as they might be tempted to play with it or prod at it, which could loosen the heater and cause an accident. You should also not use it in an aquarium with aggressive fish such as cichlids.

The heater automatically switches off when the temperature rises about 2 degrees above the set temperature and switches on again when the temperature falls about 2 degrees below the set temperature. The heater also shuts off automatically if the water temperature rises above 97 degrees Fahrenheit.

There’s an external temperature controller provided, which lets you set the temperature between 75 degrees Fahrenheit and 91 degrees Fahrenheit at intervals of 2 degrees.

Rotate the pointer to a particular temperature marked on the dial and not between the values. For example, if you want the water inside to be at 78 degrees, then rotate the pointer to 79 degrees and not between 77 degrees and 79 degrees.


  • Keeps the temperature in the aquarium stable by switching off when it rises above the required temperature and switching on when the temperature drops.
  • An external temperature controller is provided, which is easy to use.
  • It’s a durable heater and includes a safety guard.


  • Once the suction cups become loose, it could cause an accident, which is a bit of a worry.
  • There are some complaints from users regarding fluctuations in temperature.

4 out of 5 stars (4 / 5)

AquaTop Premier Glass Heater: Versatile and Safe Glass Heater

The AquaTop HTG series heater is a fully submersible glass heater. It includes a thermostat control, which makes it really easy to adjust the temperature when required, and its built-in glass component makes it durable. You can set the temperature between 68 and 93 degrees Fahrenheit.

It can be used in both saltwater and freshwater aquariums and can be placed either vertically or horizontally. An LED indicator light is placed on the top, which remains switched on while it’s heating.

It’s available in 50-watt, 100-watt, 200-watt, 300-watt and 400-watt variants. So, depending on the size of the aquarium you can pick a different version. The price will vary accordingly. The 50-watt version is suitable for aquariums up to 13 gallons, the 100-watt version for aquariums up to 25 gallons, the 200-watt version for aquariums up to 50 gallons, the 300-watt version for aquariums up to 60 gallons and the 400-watt version for aquariums up to 100 gallons. The dimensions of the heater are 11.5 x 1.2 x 1.2 inches and it weighs 8.5 ounces.


  • Once you set the temperature, the heater will automatically turn off when the water reaches that mark or when the water level in the aquarium is too low.
  • It can be placed both vertically and horizontally, so it can be used in a variety of aquariums.
  • The thermostat control is easy to use and safe.
  • There’s a protective guard for the heating element, which makes it safe to use.
  • All five versions are priced affordably.
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  • You will need a separate thermometer to check the temperature of the water, because there’s no display on the heater and some users have complained that there’s no indication of temperature on the thermostat control either.

3.5 out of 5 stars (3.5 / 5)

Uniclife HT-2300 Heater: Standard Features at a Low Price

The Uniclife HT-2300 is a submersible heater, which is particularly suited for tropical freshwater marine life. It’s best suited for 35 to 80 gallon aquariums.

The heater is made of quartz glass, which the company claims is shatterproof and doesn’t cause electric shocks.

It can be submerged completely because of its waterproof design, but since the temperature control knob is located on the top, you will have to wet your hand to adjust it. The company says the heater should be fixed vertically inside the aquarium, using the suction cups, and not horizontally.

You can set the temperature between 61 and 90 degrees Fahrenheit with this heater. A sticker-like thermometer is provided with the heater to keep a track of the water temperature. The various temperatures are marked on it and it indicates the temperature by changing color.


  • It’s a decent heater with all the necessary features and is available at a low price.
  • The heater is covered with a shockproof protective layer, which is useful.
  • A stick-on thermometer is included with the heater to track water temperature.


  • Even though it says that the heater can deliver in large aquariums, it’s suitable for 20 to 30-gallon aquariums at best. You would need two of these heaters in a 80-gallon aquarium.
  • There’s one year explosion-proof warranty, during which period you can get a replacement. This is quite weird and is a cause for concern.

3 out of 5 stars (3 / 5)

ViaAqua Submersible Heater: No-frills Heater

This fully submersible heater is made of top quality quartz glass, which is shatterproof. The ViaAqua heater can be used both in freshwater and saltwater aquariums. It can be fixed inside the aquarium using the suction cups. It features a built-in thermostat to enable temperature control and a temperature reader that’s visible underwater.


  • All of the standard features are available in this heater at an affordable price.
  • It’s not a fancy heater, but gets a job done without hassles.


  • There are complaints regarding discrepancies in temperature settings. The temperature set on the heater is either a little lower or higher when checked with an independent thermometer.

2.5 out of 5 stars (2.5 / 5)

ViaAqua 50-Watt Submersible Heater: Keep Track of Temperature Underwater

This fully submersible heater is made of quartz glass, which makes it shatterproof. This 50-watt model is ideal for 10-13 gallon aquariums. It can be used in both saltwater and freshwater aquariums. Installing the heater is very easy using the twin suction cups. The ceramic core of the heater ensures that heating is even. The temperature can be adjusted with the controller on the top of the heater.


  • The temperature setting is clearly visible when the heater is underwater.
  • It includes a water level line to help you keep track of how full the aquarium is.
  • A red light switches on and off to inform when the power is on and off, respectively.


  • The after-sales service or customer care service provided by the company isn’t up to the mark.
  • Some users have complained about water entering the heater.

2.5 out of 5 stars (2.5 / 5)

Cobalt Aquatics: Accurate Temperature Control

This electronic, fully submersible heater sports a flat design. It features a touch-based control system, with an LED display, which makes it really easy to operate. The thermostat maintains accurate temperature, with a maximum leeway of 0.5 degrees Fahrenheit. The range within which you can set the temperature is 66-96 degrees Fahrenheit. It can be installed in both freshwater and saltwater aquariums.


  • The LED display shows both the temperature set by you and the current temperature of the water in the aquarium.
  • It’s equipped with a thermal protection system, which automatically shuts down the heating when it crosses a certain temperature.
  • It comes with a 3-year warranty, which not too many manufacturers offer.


  • Sometimes the suction cup doesn’t work perfectly and the heater slides down a bit.
  • The instructions provided with the heater are a bit confusing.

3.5 out of 5 stars (3.5 / 5)

Zacro Submersible Heater: Auto Thermostat and Digital Temperature Display

The Zacro heater has excellent heat transfer efficiency and features a precision sensor probe to control any temperature error. It’s also equipped with a flame retardant for safety. The inner temperature controller is located on the top of the heater. You can set the temperature between 68 and 94 degrees Fahrenheit. It’s ideal for 50-80 gallon aquariums and offers 300 watts of power.


  • The precision sensor, auto thermostat and flame retardant features makes it a really safe heater.
  • The heater turns on automatically if the water temperature is lower than the temperature set by you.
  • It comes with an 18-month warranty.


  • The display light and the indicator lights are extremely bright, which keeps the aquarium illuminated at night and can create problems for the fish.
  • The temperature controller shifts the temperature by 2 degrees at a time, which can be an issue at times.

4 out of 5 stars (4 / 5)

Conclusion: What is the Best Aquarium Heater?

You must now have a much clearer idea about which heater meets your requirements the best.

Incase you got lost in all the reviews and comparison, our research shows that the best aquarium heaters currently available are:

1Hygger Titanium Heater

4.5 out of 5 stars (4.5 / 5)Check Pricing
2Fluval E Electronic Heater

4.5 out of 5 stars (4.5 / 5)Check Pricing
3EHEIM Jager TruTemp Submersible Heater

4 out of 5 stars (4 / 5)Check Pricing

Any of these models should do a strong job for you; just be sure to select one of a suitable size for your aquarium.

The well-known brands are naturally a little more expensive, but typically offer a good performance over longer periods of time.

One final thing to keep in mind while making your selection is that if the room temperature is likely to fall below 50 degrees Fahrenheit, then buy a heater one size bigger than the recommended size for the aquarium.

Richard Adams

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