When it comes to aquarium components, one of the most important is a reliable tank heater. What follows is a closer look at the best aquarium heaters and a guide to what you need to know to make sure you choose the right heater for your needs.

Fish Tank /Aquarium


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Aqueon Pro Heater Aquarium Heater 50 Watt

Cobalt Aquatics Neo-Therm Aquarium Heater

ViaAqua Quartz Glass

What Is An Aquarium Heater?

An aquarium heater is a device that is used to help regulate water temperatures inside your aquarium. Almost all homes will experience temperatures that will cause the water to cool below the desired levels that a tropical tank needs.

Why Is Water Temperature Important?

Fish are classified as poikilotherm animals. This means that their internal temperatures can widely vary. They are unable to produce their own internal heat which prevents them from keeping their body temperature consistent.

Due to this fact, the body temperature of fish is affected by their environment. Their internal body temperature will mirror that of the water temperature in the tank. Most freshwater and saltwater tanks need to be maintained between 71 to 86 degrees Fahrenheit, depending upon the types of fish that are kept in it.

Many fish species have a livable temperature range that is smaller than that. Choosing a good quality heater will help maintain a more consistent temperature. Fluctuations in temperature can stress your fish leading to illnesses. Most tropical and saltwater fish that are housed in cooler temperatures will be unable to thrive and may even die.

How Do Aquarium Heaters Work?

An aquarium heater is made of a few components. The sensor is able to determine the water temperature that surrounds it and will signal this to the thermostat. The thermostat component marks the desired minimum and maximum temperature levels and will activate and deactivate the heating element to keep the water within the desired range.

What Types Of Aquarium Heaters Are Available?

Immersible Heaters

These are often called hanging heaters as the unit controls often hang over the side of the tank with the heating element submerged in the water. This style of aquarium heater is one of the most commonly available on the market. They are found quite often in starter aquarium set-ups and considered by some to be a great option for those new to keeping fish.

Submersible Heaters

This type of aquarium heater is completely submerged in the water of the tank. Many aquarium enthusiasts consider this type of set-up more efficient for maintaining water temperatures than immersible heaters. You must keep in mind placement and spacing when using a submersible heating unit.

In-Line Heaters

A heater in this category is not placed into the tank at all. They are located between the tank and the filter or sump that you use. Many fish keepers feel that these types of heaters are more effective for larger aquariums and they prevent your fish from coming into contact with the heating element.

In-Sump Heaters

Just like an in-line heater, this type of device is located outside of the tank. It can offer similar benefits that an in-line will, but will also take up more room. They are placed into the sump itself, and many owners feel that they are easier to perform maintenance on.

Substrate Heaters

These devices are buried underneath the substrate of your tank. The heating element will usually be made of wires. These types of heaters are more often found in tanks that house plants, as the substrate can keep root temperatures cooler than desired.

What Things Should You Consider When Looking At Heaters?

Heater Location

An in-line heater is located outside of your aquarium, so there are no extra considerations for the tank itself. You will need to make sure that you have extra room for an in-line heater though. The location must be accessible in order for you to maintain it easily.

Submersible and substrate heaters will require an access point for power and/or sensor cords in the aquarium lid. An immersible heater will require additional room along the top of the tank for proper placement.

Heater Power

Aquarium heaters come in a variety of sizes. The size you will need will be influenced by the size of your tank. Smaller tanks may require a mini-heater, while larger tanks may require more than one heater. Many manufacturers will rate their products to aid you in your selection.

Heater Placement

With heaters located inside of a tank, location is a factor. Substrate heaters will be harder to maintain as they are buried. Submersible heaters require space to prevent fish from getting caught between them and the tank surface. Locations near water flow sources are also recommended.

Best Aquarium Heater Reviews

Aqueon Pro Heater Aquarium Heater 50 Watt

A durable submersible heater unit for a ten-gallon tank.

The Pro Heater is constructed with durability in mind, which is a great consideration for those who may be overly worried about the unit cracking and exposing the electrical elements. The adjustable temperatures range between 68-88 degrees Fahrenheit.

The heater components are durable, which is something to consider with cracking or shattering.

This heater is submersible, and has a handy auto shut-off that activates should it overheat. It will then reset itself after it cools down.

The thermostat readings can vary plus or minus a degree, which may be an issue if the heater is being used at the edge of the setting range.

The Aqueon Pro Heater comes with a limited lifetime warranty, which is comforting when investing in a higher priced heater.


  • Durable construction prevents breaking and cracking
  • LED uses colored lighting to indicate heater status
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    Limited lifetime warranty


  • Small temperature variances from readings an issue near range extremes
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    Price point is higher than some at this size

Neo-Therm Aquarium Heater - Cobalt Aquatics 50 Watt

An electronically controlled heater with one touch heat setting features.

The Neo-Therm heater is submersible and has a modern design that is flat when compared to other heaters of a similar type. This can be an advantage in a tank with more limited space.

The display shows you the temperature settings and tank temperature at the same time.

The 50-watt unit is designed to handle tanks up to 12-gallons, which can be advantageous for fish keepers that have ten-gallon aquariums. In the event of a power failure, the programmed settings will be retained.

There may be some variance in readings that can cause the unit to keep temperatures a degree or two lower with tanks larger than ten gallons.

The Neo-Therm is able to operate at higher temperature settings up to 96-degrees Fahrenheit.


  • An easy set one-touch system design offers easy temperature control
  • Multiple readings show temperature setting and tank temperature simultaneously


  • The Neo-Therm may vary a degree or two at the higher temperature ranges
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    This submersible has a high price point compared to other 50 watt units

ViaAqua 50-Watt Quartz Glass Submersible Heater

A quartz glass heater that has highly visible heat settings.

This heater is fully submersible and is rather easy to install with the use of suction cups. The product has been designed to be used in tanks up to 13-gallons, which can be a nice feature for owners of tanks smaller than this.

The temperature settings are highly visible and can be seen in either Fahrenheit or in Celsius.

As it is designed with fresh and saltwater use in mind, this unit may prove to be more resistant to corrosion than other heaters. It comes with a water level line that helps you place the heater properly.

The quartz glass may prove brittle if you handle the heater roughly.

The ceramic heater core is built with even heat dispersion in mind.


  • A highly visible settings readout on the heater itself
  • The adjustment knob is easy to manipulate
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    It is designed to be used in fresh or in saltwater tanks


  • The quartz glass design may not be as sturdy as other heaters in this range
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    Works off of a GFCI outlet which may limit plug-in options for the heater


As we are sure you noticed, all products reviewed were all submersible heaters. We feel that this type allows for the best balance between efficiency and set up. Of the products reviewed, we felt that the Aqueon Pro Heater Aquarium Heater 50 Watt offers the best balance. A higher price point invests in a durable product with a limited lifetime warranty.

The settings are easy to use and the indicator lights show the heater's status. For a ten-gallon tank, this heater should supply consistent heat that is dispersed evenly. We hope that you are warmed up to trying it!

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