One of the greatest benefits we have as humans is our bodies’ ability to produce its own heat. This is unlike fish, which don’t produce their own heat and rely on the temperatures water. Explains why it’s crucial to have the best aquarium heater installed in your aquarium.

The device will keep the aquarium temperatures at their best—ensuring the overall well-being and comfort of your pets (the fish).

In the following guide, we cover everything you need to know about aquarium heaters. Including various types of heaters, how to pick the best one and the 10 top models on the market today.

Let’s dive in.

 What Is an Aquarium Heater? 

An aquarium heater is a thermal device designed to help maintain proper temperatures of water in the aquarium or fish tank.

From your middle school biology, you can recall that the fish are cold-blooded animals that cannot regulate their body temperature. That said, this device basically raises the temperature of the aquarium to around 22-30 °C (71-86 °F). Which is the temperature range for most marine and freshwater fish species.

Some homeowners believe that all they need to do is the heat their house to provide their fish with warmth. But that isn’t true. The aquarium water doesn’t need to be just warm; the temperatures should stay as stable as possible.

If you’re keeping the marine fish, it’s important to know that they’re usually more sensitive to fluctuating temperatures.

Most of the heaters come with a thermostat that helps keep the temperatures constant throughout.

WARNING: A bad heater can be bad news to your fish. It can easily cook your fish, electrocute them or even explode and leach toxic chemicals into your fish tank (if it cracks) or even explode (if water gets into it).

Keep reading for more info on how to choose a quality water heater for dish tanks that meet your needs and expectations.

 Our Best Aquarium Heater Picks: 

 1. Tetra HT Submersible Aquarium Heater 

Tetra HT Submersible Aquarium Heater aquarium heater reviews as one of the most reliable heaters for your fish tank. The 50-Watt device is one of the smallest fish tank heaters on our list. And this makes it ideal for aquariums with a capacity of around 2 to 55 gallons.

When it comes to executing its job, this heater never disappoints. It’s equipped with an electronic thermostat that automatically adjusts its heat output. The option ensures water in your aquarium remains at a stable 78 degrees. This is the ideal temperature for most tropical fish.

The included indicator lights will make this heater easy to operate for you. The RED light shows that the heater is heating and the GREEN light indicates its standby.

To install this heater, you only need to fully submerge it in the tank vertically or horizontally. With its small footprint, you can easily conceal from spying eyes by placing it behind plants or any other decor.

If your aquarium has a hood or glass canopy, this heater will be even more effective as heat will be contained inside. For your own safety, the heater automatically shuts off on detecting an electric short.

 Highlighted features: 

• Fully submersible heater
• Built-in electronic thermostat
• Indicator lights included
• Safety auto shut off

 2. Aqueon Pro Adjustable Heater 

Aqueon Pro Adjustable Heater is another top-rated heater for fish tanks. This particular heater comes in different Wattages, ranging from 50 to 250W, so you can easily find one that meets your specific fish tank needs.

It comes equipped with an electronic thermostat which enables you to set the right temperatures for your lovely pets, ensuring their overall well-being and comfort. It allows you to adjust its heat setting from 68 to 88 degrees F, depending on whether you’re keeping marine or freshwater fish.

The included LED lights will make this heater easy to operate for you. When you see the red light, it means that the water is working (heating) and when you see the green light, it says the device has reached your set temperature. The auto shut-off function also helps prevent overheating (ensuring your safety and that of your fish).

Apart from excellent performance, this heater is also designed to last. It boasts of a durable, non-corrosive shell for maximum strength and even distribution of heat across all the corners of your aquarium.

 Highlighted features: 

• Adjustable heater setting
• Armed with electronic thermostat
• Shatterproof construction
• Fully submersible heater
• Automatic shut-off for safety
• Indicator LED lights
• Limited lifetime warranty

 3. Fluval E 100-Watt Electronic Heater 

If your aquarium has a bigger water capacity, then the best fish tank heater for you is Fluval E 100-Watt Electronic Heater. This model comes with a power rating of up to 300 Watts which makes it suitable for aquariums with a capacity of up to 100 US gallons.

As one of the most advanced submersible heaters, available today, this device uses the VueTech technology which ensures precision and safety during water heater. With its easy to use adjustment lever, this heater will enable you to precisely set your heater temperature in increments of 0.5 degrees C.

The safety of your fish is also prioritized in this particular heater. This is evident from the integrated fish guard which prevents your pets from getting into direct contact with the heater core. What’s more, the glass sleeve comes protected against shocks that are common with larger fish species.

The LCD temperature display, colored alert display system, slim profile mounting bracket, and a safety auto shut-off make this heater incredibly simple to operate for you.

 Highlighted features: 

• Dual temperature sensor
• Fast heat technology
• Easy-read LCD temperature display
• 300W; suitable for aquariums up to 100 gallons
• Factory calibrated heater
• Automatic shut-off for safety

 4. EheimJager Aquarium Thermostat Heater 

If you’re looking for a reliable 300 watt aquarium heater, then EheimJager Aquarium Thermostat Heater should be at the top of your top choices. This is also 100% fully submersible heater designed with both saltwater and freshwater aquariums in mind.

The ultra-modern thermal device offers you some of the greatest features you can ever find in an aquarium heater. One such feature revolves around the TruTemp Dial—which allows you to recalibrate the heater within an accuracy of +/- 0.5F degree. This results in precise temperature readings, ensuring your pets live in a comfortable environment.

Even more interesting, this heater is designed using 100% shatterproof, shockproof lab-grade glass. This means that it doesn’t leach any chemicals, pollutants and biological substances into the aquarium, which can endanger their life. Besides, this glass can withstand extreme temperature fluctuations and last a lifetime.

With the On/Off indicator light, you’ll never have to guess the heater function. For maximum safety assurance, the heater will automatically shut off when you remove it from water or when the water levels get too low.

The included mounting brackets and suction cups facilitates easy and flexible heater placement in your aquarium.

 Highlighted features: 

• Fully submersible heater
• Thermo safety control
• Laboratory-grade glass construction
• On/Off indicator light
• Simple and safe recalibration
• Extra-long power cord

 5. Cobalt Aquatics Neo-Therm Aquarium Heater 

If you’re looking for the best saltwater aquarium heater, this is your part! Cobalt Aquatics Neo-Therm Aquarium Heater has a temperature range running from 66 degrees F all the way up to 96 degrees F—making it perfect for saltwater as well as freshwater aquariums and terrariums.

The fully submersible heater features a super flat design, so it doesn’t take up a huge space in your aquarium. It also presents you with an easy-to-set “One-Touch” control system for easy operation.

The heater comes equipped with an advanced electronic thermostat with an accuracy of ±0.5ºF, enabling you to set just the right temperatures for your pets. With a LED screen that displays both the Tank Temp and Set Temp simultaneously, it becomes quite easy to monitor how your heater is working.

For your own safety, the heater also comes with integrated thermal protection circuitry that automatically shuts down the heater to prevent overheating. The shatterproof outer casing makes this heater virtually indestructible and highly reliable.

 Highlighted features: 

• Steady, accurate temperature control
• Shatterproof construction
• Super-flat (1/3-in thick) design
• 3-year warranty

 6. Aqueon Submersible Aquarium Heater 

Also from Aqueon, we have another fully submersible aquarium heater. While the highest power rating of the previously discussed Aqueon is 250 Watt, this particular hater has up to 300W. This makes it a good choice for those with aquariums with a bigger capacity of up to 100 gallons of water.

This heater lets you make precise temperature settings to degree F. Its temperature scale runs from 68 to 88 degrees F to enable you to set favorable conditions for both saltwater and freshwater fish. When this device is heating your aquarium, an LED light will turn on to show you its current status.

Just like its sisters from Aqueon, this heater is also constructed 100% thermal shatter-resistant quartz glass. This enables the heater to withstand extreme temperature fluctuations, absorb impacts, and last longer than most of the heaters out there.

As with other top-rated fish tank heaters, this model is also programmed to automatically shut off when not properly submerged to prevent overheating and damages. You can place the heater vertically or horizontally in your aquarium.

 Highlighted features: 

• PreciAse temperature setting
• Suitable for aquariums up to 100 gallons
• Shatter-resistant construction
• Automatic safety shut off
• LED light for easy operation
• Limited lifetime warranty

 7. Mylivell Aquarium Heater Submersible Fish Tank Water Heater 

The 7th spot on our list of top-rated aquarium heater reviews, we have the Mylivell Aquarium Heater. This is one of the most affordable aquarium heaters currently available on the market. In other words, we recommend it to hobbyist fish keepers on a budget.

Don’t judge this thermal device by its cost though! It’ll meet all your fish tank heating expectations. It has an automatically adjustable temperature to help ensure maximum comfort of your fish. The fact that it has a temperature range of 20°~34°C(65° F – 93° F) means it’ll offer ideal living conditions for both saltwater and freshwater fish.

Like most of the other heaters on this list, this Mylivell device also comes with a fully submersible design. It has a power rating of 200W and can effectively heat up an aquarium with a water volume of up to 20 gallons.

With an advanced design featuring quality quartz glass plus double seal material, this heater is safe to operate and will last longer than most of the competition. The 2 suction cups included in the box facilitates hassle-free heater placement. And the polarized plug keeps off electrical shocks.

 Highlighted features: 

• High-quality quartz glass construction
• Automatic temperature adjustment
• Fully submersible design
• Power: rating 100W
• Suggested water volume: 20 gal.
• Indicator lights for easy operation

 8. Pedy Aquarium Heater 

If you’re still looking for the best saltwater aquarium heater, Pedy Aquarium Heater is another reliable device for you. The fairly priced heater is designed using titanium alloy to make it shatterproof and corrosion-resistant when fully submerged in saltwater or freshwater.

The device takes advantage of titanium’s unparalleled heat transfer efficiency to make the heating time shorter and more efficient. With a power rating of 300 Watt, this thermal device is ideal for aquariums as large as 50-60 gallons of water. With a temperature range of 68 to 93 degrees F, this heater will enable you to set the right temperature for both freshwater and saltwater fish.

Besides titanium alloy, this heater also features a double seal material plus insulation Teflon—all of which work together to make it explosion-proof, IP68 waterproof, shatterproof, and safe for you and your pet fish.

To avoid overheating and possible damages, the heater also comes equipped with over-temperature protection that automatically shuts off when it’s not submerged properly.

 Highlighted features: 

• 300W titanium aquarium heater
• Fully submersible
• Water Volume: 50-60 gallons
• Quality titanium alloy construction
• Shatterproof and anti-corrosive
• Overheating protection
• 1-year free replacement service

 9. Hygger Submersible Aquarium Heater Fish Tank Water Heater 

For those who own aquariums with a water volume of 26 to 53 gallons, Hygger Submersible Aquarium Heater is the perfect choice for you. With a 200Watt power rating, it’s capable of warming up your aquarium and ensuring your fish thrive in a favorable environment.

The affordably priced device also features a fully submersible design, just like the other heaters we’ve discussed in this list. It boats of top quality quartz glass material, waterproof double seal material, and a shatter-resistant construction. This durable construction helps promote safe operation while preventing your fish from punching and scalding.

Equipped with an electronic thermostat, this heater also ensures a precise temperature within a range of 61 to 91 degrees F (16°C ~ 32°C).

This heater is super-easy to install and use. The two included suction cups help you mount it vertically. It’s suitable for both freshwater and saltwater fish. And it has thermo-safety protection that automatically shuts off the heater when its removed from the water.

 Highlighted features: 

• Fully submersible heater
• Made of high-quality quartz glass
• Shatterproof construction
• Built-in electronic thermostat
• Perfect for saltwater and freshwater
• Power: 200W; tank capacity: 26-53 gallons

 10. Elive Easy-Set 50W Submersible Aquarium Fish Tank Heater 

Our aquarium heaters review comes to an end with the Elive Easy-Set 50W Submersible Aquarium Heater. This heater comes with a power cord of 8 feet long, with a 50 Watt power rating. It’s sure to make your pets happy, whether it’s freshwater or saltwater fish.

The fully submersible heater is quite easy to set up. You just plug it in and its ready to go. The LED indicator light will help confirm that your heater is working well. Because it’s temperature adjustable, you can easily set your desired temperatures over a scale of 68°F and 93°F (20°C – 34°C).

As you’d expect in any top-rated aquarium heater, this model is also designed using quality materials (quartz glass, to be precise) which makes it shatter-resistant and long-lasting.

 Highlighted features: 

• Fully submersible heater
• Durable, shatter-resistant quartz glass
• Ideal for both salt and fresh water
• Temperature adjustable heater
• Easy, quick setup

 Here’s What To Look For Before Getting One 

When you get down to the business of choosing the best aquarium heater, you’ll be overwhelmed by the many, many aquariums heaters on the market today.

Luckily, you can make the shopping process easy and fast by focusing on various crucial features of an aquarium heater that we’ll be sharing you with below.

 Type of Aquarium Heater 

The number one thing you need to bear in mind when looking for an aquarium heater is that it comes in multiple types. Knowing how each of them works and its intended use will help you choose the one that meets your specific needs.

Here are the FOUR most common types of aquarium heaters on the market:

 1. Submersible aquarium heater 

As the name suggests, this is a type of heater that you place right inside your aquarium. It’s also the most popular type of heater among hobbyist fish keepers. The heater is relatively cheap and easy to set up.

When using this heater, however, make sure you leave enough space in your space in your aquarium, so that your fish can move around freely. You should also ensure that it doesn’t touch the gravel to prevent differences in heat conductivity from cracking the glass.

 2. Immersible aquarium heater 

Also known as a hanging heater, this type of fish tank heater comes with a glass tube encompassing the heating element and is designed for hanging over the fish tank. These heaters also enjoy some popularity and are great for people who are new to keeping fish.

It’s always important to ensure that this heater is fully secured before using it on your aquarium system to prevent it from electrocuting your fish or even starting a fire. This heater shouldn’t be used in brackish or marine fish tanks as the salt water can easily get into the tube and cause corrosion.

 3. Substrate aquarium heater 

This particular heater is designed to be buried in the substrate matter lining the bottom of your fish tank, hence the name “substrate.”

If your aquarium has plant life as well, this is the best heater you can get for the tank.

The heater is less common and harder to find in the stores. It’s a bit pricey

 4. External aquarium heater 

External heaters are usually placed outside the aquarium system—installed in the sump or connected between the tank and sump. If you come across heaters labeled as an in-line or in-sump water heater, they mean the same thing as an external heater.

These heaters are regarded as the safest option for your pet fish since they don’t come into direct contact with the device. This minimizes the chances of accidental burns and cracks.

Unfortunately, these heaters are quite expensive and can be a bit challenging to set up.

 Look for A Durable Heater 

If the glass housing the heating element gets damaged, serious dangers can set in…like overheating and leakage of toxic chemicals into your fish tank.

For this reason, we always advise our readers to look for a durable heater—ones that constructed using shock-resistant and shatterproof glass material. This will ensure the heater doesn’t get damaged, even in the event of extreme temperature fluctuations or when hit by the larger species fish.

All the 10 best aquarium heaters we’ve outlined for you above are made of 100% shatterproof and shockproof glass materials for maximum strength and durability.

 What Size Should You Buy? 

Another crucial thing to consider when buying an aquarium heater is its size. And this should be directly related to the size of your fish tank.

If you buy a heater that’s too small for your tank, it might not be able to effectively heat your entire tank, risking the death of your fish.

As a rule of thumb, always go a heater size 3-5 Watts for every gallon. For instance, if your aquarium has a capacity of 20 gallons, look for a heater rated 60 to 100 Watt.

The manufacturers usually recommend the suitable tank volume to go with their devices. Look out for this information to make it even easier for you to determine the ideal size of the heater to buy.

If you reside in areas with cold temperatures, getting a higher wattage is even better!

 Safety Features 

The most important safety feature that every heater should have is automatic shut-off. This will help automatically put off the device when it’s removed from the water or when the water levels drop unexpectedly—preventing overheating and fires.

Temperature sensors are also a crucial safety feature in that they automatically turn off or start your heater to prevent overheating and dangerous cold drops.

Above all, make sure the heater has an indicator light to help you easily determine when it’s on or off.

 Check The Price! 

You should also come up with a budget of the amount of money you’re willing to spend on a new heater for your fish tank.

The price fluctuates from heater to heater depending on the manufacturer and the features they come with.

Again, the rule of thumb applies here: the more you pay, the better it gets. If you’re on a tight budget, and you’re willing to do some good research, you can still get a great heater for the money that meets all your aquarium heating needs.

 Extra features to look for in a fish water tank heater: 

• Adjustable temperature: this feature comes handy when you want to set your desired temperature to meet your specific fish tank heating needs.
• Temperature readability: a digital temperature gauge will enable you to easily view the current aquarium water temperature. Models that come with colored or LCD displays are worth consideration.
• Easy controls access: look for a heater with easy to access controls/knobs (even when fully submerged in water) for hassle-free operation.
• Ease of maintenance: just like your fish tank, the heater needs some cleaning and maintenance. Choosing a heater that’s easy to clean and maintain will save you time and headaches.
• Warranty: because the device you’re buying can unexpectedly get damaged, looking for a model with manufacturer warranty is highly recommend.

 How To Place and Use a Heater In Fish Tank? 

 How you put your heater in the fish tank will determine how effective it is in performing its job of warming water for the fish. 

According to experienced fish keepers, the best way to place your heater (assuming you’re using a fully submersible heater; which we highly recommend to you) is near the flow of the water (inlet or outlet) from the filter. Or in the stream of the power head.

The reason for choosing such a strategic position is it’ll help evenly disperse heat through your aquarium via conduction—where heat moves from hot to cold areas to achieve thermal equilibrium.

We also recommend you to consider placing your heater at an angle (as opposed to horizontal or vertical positioning) for even heat distribution.

The suction cups that come with your heater package will help you easily set up your new heater in your desired location.

 Once you’ve placed your heater correctly, how do you start using it? 

We recommend you to give your heater around 15 to 30 minutes before turning it on to allow the casing to interact with the surrounding water. This can go a long way in preventing cracking from sudden temperature changes.

Now turn your heater on and set it to your desired temperature. Be sure to note down the initial water temperature. If your heater doesn’t come with a built-in thermometer, you can use an external one for temperature recordings.

Allow it to run for up to 24 hours and check the temperature reading. Check the heater after every 4-6 hours and adjust the settings accordingly until you achieve the optimal temperature.

When you’re satisfied with the water temperature, add your fish into the aquarium and watch them as they swim happily in the comfortable environment you’ve just created for them.

 What Size Aquarium Heater Do You Need? 

In our buying guide section, we mentioned that size is one of the most important factors to consider when buying the fish tank heaters.

The word “Size” here doesn’t refer to the physical size of the device. Instead, it relates to the Wattage of a given heated and its ability to heat an aquarium of a given water volume.

 To put all this in a simple statement: 

The size of the heater to buy should depend on the water capacity of your fish tank (often expressed in Gallons).

The Golden Rule for heater size selection is that you should pick around 3-5 Watts heater for every gallon. Using this rule will help you easily determine the appropriate heater size for all tank sizes.

As your fish tank volume gets bigger, your heater Wattage should also get bigger.

Watch the video below for more details on how to pick the right heater size for your fish tank…

 What Temperature Should Your Aquarium Heater Be Set At? 

Remember the main reason why you bought that heater is to help maintain the right temperatures for your fish in the aquarium.

That being said, the right temperature setting will depend on the type/species of fish you’re keeping.

Generally, the temperature for an aquarium holding either freshwater or marine fish should run from 22 to 30 degrees C (71-86 °F).

This is viewed as the most comfortable temperature for most fish.

However, we encourage you to do some extra research on the profile of the fish species you’re keeping to discover the optimal temperature setting for them.

 Is It Necessary To Have a Heater in A Fish Tank? 

Yes, the heater is a vital part of your aquarium system!

If you’re one of the many fish keepers wondering whether it’s really necessary to install a water heater for fish tanks, here’s why you get one today.

As we mentioned earlier one, the fish are cold-blooded animals. Meaning they cannot regulate their body temperatures like we human beings or other mammals. For them to thrive in either open sea or your fish tank, they require the right external temperatures.

So, how are the fish able to survive in the open sea then?

Well, it’s easier for the fish to survive in the open waters simply because the heat conditions there tend to remain constant.

In your man-made habitat (aquarium), however, you’ll need to put in some extra effort to provide a comfortable living environment for your fish.

And this effort involves installing an aquarium heater.

 The two most important roles placed by a heater in your aquariums include: 

• Temperature control: the thermal device will enable you to set the temperatures to meet your specific needs. Whether you’re keeping saltwater or freshwater fish or its breeding time, you’ll need specific temperatures in the aquarium.
• Stability: the heater will also help keep the water temperatures at stable levels, regardless of the temperature in your house. This is important given the fact that temperature fluctuations can result in the death of your pets.

NOTE: Many fish keepers make the mistake of believing that by heating the room, they provide a favorable environment for their fish. Sadly, this isn’t true. Using a heater specially designed for your fish tank is and will always be the BEST way to provide a thriving environment for your fish!

 Final Verdict 

If you’re into fish the keeping hobby, then you need to know the pets you’re keeping are highly sensitive creatures. They’re cold-blooded, which means they can’t control their own body temperatures like we human beings and other mammals.

To ensure your aquarium is a good environment, you’ll need to invest in the best aquarium heater. This will help you set the right temperatures in the aquarium for the specific type of fish you’re keeping.

In this post, we’ve paraded the 10 top-rated heaters that you can install in your fish tank today to keep your fish happy at all times.

Our aquarium heater buying tips will help you easily pick the most suitable heater for your aquarium without getting overwhelmed by the multiple choices at the market today.