10 Best Aquarium Heaters in 2020

Nothing is more satisfying that cultivating a thriving home aquarium – the beauty of nature right in your own home. Keeping an aquarium is a unique challenge in comparison to owning a cat or a dog. An aquarium is a self-contained ecosystem and it takes a certain degree of effort and know-how to keep it healthy.

When it comes to keeping a home aquarium, there are certain things you need to think about. First and foremost, how will you keep the water clean for your fish? A high-quality filtration system is the easy solution to this problem. Next, how will you maintain a consistent water temperature in your tank?

That’s where an aquarium heater comes in.

Aquarium heaters are designed to keep your aquarium at a consistent temperature. These heaters come in several different forms, some with adjustable thermostats, and some without. The type and size of heater you need will depend on the size of your tank and the type of fish you keep.

Keep reading to learn more about the top 10 aquarium heaters and how to choose the right one.

Our Top 10 Picks for the Best Aquarium Heaters

#10 Aqueon Submersible Aquarium Heater

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If you’re in the market for a simple and affordable aquarium heater that comes in a wide range of sizes, the Aqueon Submersible Aquarium Heater may be the right choice for you. This aquarium heater features precise temperature settings to 1-degree between the range of 68°F and 88°F. When the water temperature drops below your chosen setting, the heater automatically turns on with an LED indicator light to let you know it’s running.

The Aqueon Submersible Aquarium Heater features a shatter-resistant construction and it is fully submersible. This makes it easy to place the heater near your filter output to help ensure even heat distribution. The heater is covered by a limited lifetime warranty and comes in sizes ranging from 50 watts up to 300 watts.

Pros: Precise 1-degree temperature adjustment, automatic on/off, LED indicator light, shatter-resistant construction, automatic safety shutoff and overheat protection, up to 100 gallons, limited lifetime warranty

Cons: Not for tanks over 100 gallons, no automatic shut-off if water level drops

#9 Marineland Precision Heater

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The Marineland Precision Heater is a wonderful option if you’re looking for an affordable heater that doesn’t take up a lot of space. Available in 8 sizes ranging from 50 watts all the way up to 400 watts, this aquarium heater can accommodate tanks up to 125 gallons in capacity. Because it is so affordable, you can even purchase two smaller heaters to use in a very large tank to ensure even distribution of heat. Plus, the mounting bracket has 3 windows, so you can view the current temperature with ease.

With an adjustable temperature dial, the Marineland Precision Heater allows you to set your desired tank temperature within 1 degree. The Thermal Switch automatically turns off when the ideal water temperature is reached (or if it goes above an internal preset) and turns on when the temperature drops. This heater features an advanced heating element that contains a mica core for superior heat transfer and enhanced durability.

Pros: Easy-to-view sliding scale to check temperature, available in 8 sizes, rated for tanks up to 125 gallons, adjustable to 1 degree, mica core for superior heat transfer, automatic on/off Thermal Switch

Cons: Glass may not be shatterproof, thermostat may not be completely accurate

#8 Aquatop Quartz Glass Submersible Heater

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You don’t necessarily need to spend a small fortune on an aquarium heater if all you want is something simple that gets the job done. The Aquatop Quartz Glass Submersible Heater is a no-nonsense, highly affordable aquarium heater that is fully submersible and available in a range of sizes from 50 to 300 watts. This aquarium heater can be placed anywhere in the aquarium and it has a generous temperature range from 68°F to 93°F.

The Aquatop Quartz Glass Submersible Heater is designed to keep your tank temperature consistent by automatically turning on when the water temperature drops below the level you set on the thermostat and turning off when it gets high enough. There is an easy-to-read thermometer and an adjustable temperature setting with over-wind protection. Plus, this heater is suitable for both freshwater and saltwater aquarium use.

Pros: Wide temperature range (68°F to 93°F), fully submersible, durable glass construction, easy to read/use temperature setting, thermostat has over-wind protection, sizes from 50 to 300 watts

Cons: Temperature reading not 100% precise, glass may not be shatterproof


#6 Fluval E Electronic Heater

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Though the Fluval E Electronic Heater looks very different from most of the heaters on this list, it offers a number of unique features. This heater comes in three sizes from 100w to 300w, and it can accommodate temperatures within the range of 68°F to 93°F. Plus, with dual temperature sensors, you get an accurate real-time reading of the tank temperature so you can make adjustments.

If you’re looking for an aquarium heater with superior safety features, the Fluval E Electronic Heater is a good option. This heater has Fast Heat technology with a built-in safety shutoff and integrated fish guard to protect your tank inhabitants. It also comes with a slim profile mounting bracket and a colored display alert system. Plus, it is durably constructed to last a long time.

Pros: Generous temperature range (68°F to 93°F), durable construction, LCD real-time temperature display, safety shutoff feature, Fast Heat technology, integrated fish guard

Cons: Somewhat expensive, shouldn’t be used horizontally, setup is a little tricky

#5 Hydor In-Line External Aquarium Heater

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While submersible aquarium heaters are fine for small to medium-sized aquariums, they are less efficient for larger tanks. The Hydor In-Line External Aquarium Heater is an in-line heater that hooks up to your filter line to heat the water before it enters your tank. This heater is suitable for both freshwater and saltwater applications and it is very easy to use.

The Hydor In-Line External Aquarium Heater features elite PTC technology which ensures that the heater maintains the ideal temperature range without overheating. This means that you can rest easy knowing your tank won’t overheat and hurt your fist. You should install the heater in a vertical position, but installation is easy, and the performance is unmatched for quality.

Pros: Hooks directly into the filter line, suitable for freshwater and marine applications, features elite PTC technology to prevent overheating, easy to install and use, keeps tank water consistent

Cons: Can be tricky to adjust, no visible temperature display, cannot be mounted horizontally

#4 Eheim Jager Aquarium Thermostat Heater

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If you’re in the market for a high-quality aquarium heater with many size options and myriad safety features, the Eheim Jager Aquarium Thermostat Heater is a great option. This aquarium heater comes in eight sizes ranging from 25 watts to 300 watts, so it can accommodate tanks from 7 to 150 gallons. One thing to keep in mind with this model, however, is that the heater gets longer as you go up in wattage – the largest size measures almost 15 inches which may limit your options for tank location.

The Eheim Jager Aquarium Thermostat Heater features a TruTemp dial which allows you to calibrate your tank temperature within a half degree. There is also a Thermo Safety Control mechanism that shuts the heater off when it’s removed from water and resumes function once submerged. This heater also comes with a mounting bracket and suction cups for installation and an extra-long power cord.

Pros: Shatterproof glass construction, TruTemp dial adjusts from 65 to 93, adjustable within a half degree, Thermo Safety Shield automatic shutoff, included mounting bracket, 9 sizes to choose from

Cons: Higher wattages can become very long, some users report overheating

#3 Tetra HT Submersible Aquarium Heater with Electronic Thermostat

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Easily one of the most popular aquarium heaters on the market, the Tetra HT Submersible Aquarium Heater with Electronic Thermostat is a great option for smaller aquariums. Available in a 50w and 100w size, this heater can accommodate tanks up to 30 gallons. This aquarium heater is fully submersible and perfectly sized for small aquariums. It can be installed vertically or horizontally as well, so you can place it wherever you happen to have space.

The Tetra HT Submersible Aquarium Heater with Electronic Thermostat features a built-in electronic thermostat that automatically maintains the tank temperature at 78°F which is ideal for most tropical fish. The heater also features an indicator light to let you know when it is activated – it turns green when the desired temperature has been reached and red when it is heating up.

Pros: Built-in electronic thermostat, indicator light turns red/green, fully submersible, low footprint design, can be installed vertically or horizontally, two sizes to choose from

Cons: Temperature is not adjustable (stays at 78°F), not for tanks larger than 30 gallons

#2 Cobalt Aquatics Neo-Therm Aquarium Heater

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When you first see the Cobalt Aquatics Neo-Therm Aquarium Heater, you may not recognize it as an aquarium heater. This heater features a unique and elegant design that won’t detract from the aesthetics of your tank. Not only is this heater designed for looks, however – it is also designed to offer superior function with plenty of useful features. Plus, it has a small, flat design that works well in a variety of different spaces.

The Cobalt Aquatics Neo-Therm Aquarium Heater has an impressive temperature control system. It is a one-touch design that enables you to control the heater with ease. The temperature adjusts from 66°F to 96°F which is very generous by industry standards. There is also an indicator light that shows when the heater is activated – it flashes until the desired temperature is reached.

Pros: Unique and elegant design, works in many different spaces, one-touch temperature control, generous temperature range (66°F to 96°F), blinking indicator light, three sizes from 50w to 100w

Cons: May not be large enough for big aquariums, no digital temperature reading, suction cups could be stronger

#1 Aqueon Pro Adjustable Aquarium Heater

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The Aqueon Pro Adjustable Aquarium Heater is a top-of-the-line aquarium heater with an electronic thermostat accurate to 1 degree and a wide temperature range from 68°F to 88°F. This aquarium heater is built for durability with a shatterproof construction and it is fully submersible. Place this heater near the filter outlet in your tank for the best results with even heat distribution.

Not only is the Aqueon Pro Adjustable Aquarium Heater highly accurate and adjustable within 1 degree, but it offers several safety features as well. It has an auto shut-off to protect against overheating and it automatically resets when it cools down. When the water temperature goes below the desired setting, the red LED turns on to indicate that the heater is activated – when the temperature reaches the desired level, the LED turns green and the heater shuts off.

Pros: Shatterproof and nearly indestructible design, fully submersible, electronic thermostat accurate to 1 degree, LED light always on, automatic shutoff for safety, limited lifetime warranty

Cons: Housing is black instead of clear, larger sizes can be very long

Tips for Choosing an Aquarium Heater

When it comes to aquarium fish, there are hundreds of species to choose from. For the most part, however, aquarium hobbyists tend to prefer tropical aquarium fish over cold-water species. Tropical fish can be found all over the world in all kinds of aquatic ecosystems, and each species has its own unique requirements when it comes to tank parameters.

While water quality is at the top of the list for important tank parameter, water temperature is important as well.

Not only do you need to heat your tank to the proper temperature, but you also need to maintain that temperature. Aquarium fish can be easily stressed by changing conditions in their tank, and that includes tank temperature.

But how do aquarium heaters work, and what are the different kinds? Keep reading to find out.

The Different Types of Aquarium Heater

aquarium heaterAquarium equipment has come a long way since the hobby first gained popularity.

Whereas once it was complicated to maintain stable tank conditions, it is now easier than ever. In fact, there are entire electronic systems which can be programmed to maintain ideal tank conditions.

While advanced aquarium technology does exist, it is out of the price range for most aquarium hobbyists and there is a certain degree of satisfaction in figuring things out for yourself.

In addition to choosing a filtration system to keep your tank water clean and clear, you also need a heater to prevent temperature fluctuations and to maintain the ideal water temperature for your fish.

There are five different types of aquarium heater:

Immersible Heater – Also known as a hanging heater, this type of heater hangs on the back of your aquarium. It features a heating element encased in a glass tube that is immersed in the water. This type of heater is very common and cost-effective.

Submersible Heater – This type of heater is designed to be fully submerged in the tank so there are more options for placement. Just make sure you don’t place it where it could touch the substrate or tank decorations and ensure that fish have room to swim around it.

In-Line Heater – An in-line heater hooks up to your filtration system, placed between the tank itself and the filter. This type of heater is a great option for larger tanks and it is very efficient.

In-Sump Heater – This type of heater can be installed in your sump system to save space. They offer the same benefits of in-line heaters but take up a little more space.

Substrate Heater – These heaters are uncommon, and they generally are not very effective. Substrate heaters usually consist of heating coils you install along the bottom of the tank then cover with substrate. They may work well for planted tanks but not for total-tank heating.

Most aquarium hobbyists choose ether a submersible or in-line heater because they are the most efficient options. Immersible heaters are inexpensive and can be used for smaller tanks, but they don’t perform as well as submersible heaters. In-line heaters can be a little more expensive and they don’t work with every type of filter, so that may limit your options as well.

Once you’ve chosen a heater for your aquarium, the next step is to learn how to use it properly to maintain a stable water temperature.

Maintaining Stable Tank Temperature

Choosing the right type of aquarium heater is the first step, but then you need to determine the right size and how to use it. Most aquarium heaters are rated for tanks of a certain size, so all you should need to do is read the package and choose the one that matches your tank.

Once you’ve chosen your aquarium heater, you then need to decide where to put it.

For immersible heaters, the best place to put it is near the outlet of your aquarium filter. As the water flows past the heater, it will warm to the ideal temperature – this allows for an even distribution of heated water throughout the tank. For in-line and in-sump heaters, placement is easy. Simply install the in-line heater in line with your filter line or place the in-sump heater in your sump system.

For submersible heaters, the ideal placement is a little different. These heaters are designed to be fully submerged in the water, so you don’t have to place them near the top of the tank. In fact, some hobbyists recommend placing the heater about halfway to the bottom of the tank. Still, you should place it near enough to the filter outlet that it will distribute the heat well.

If you have a very large aquarium, you may want to consider installing two smaller heaters spaced evenly along the back wall of the tank. Having two small heaters will ensure more even heat distribution than having on larger heater.

While choosing and installing the right aquarium heater is the best way to keep your tank temperature stable, there are a few other things you should do.

Here are some simple tips:

Buy the highest-quality heater you can afford and follow all instructions in the manual to keep it in prime working condition.

Clean your heater once a month or so to prevent algae accumulation – you should also check to make sure it is working properly during this time.

Avoid placing your tank in direct sunlight or hear an air vent – these things can make it harder to maintain a stable tank temperature.

When performing water changes, try to match the new water to the temperature of your tank as much as you can or use a drip system to refill the tank.

Be mindful about choosing aquarium lighting because some systems produce a lot of heat – if you use metal halide lights, for example, you may need an aquarium chiller or auxiliary fan.

Consider replacing your heater once a year to make sure everything is working properly – submersible heaters may wear out and malfunction more quickly if installed horizontally.

With the knowledge you’ve gained here and a high-quality aquarium heater, you should have no trouble at all in maintaining the ideal temperature in your aquarium. Good luck!

For more information on aquarium heaters and installations, see theYouTube video below:

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