Many fish and invertebrates require heated aquarium water, and there are a lot of aquarium heaters on the market. While some heaters are budget-friendly, some heaters can really break the bank. Nobody wants to replace their aquarium heater every 6 months, and the same number of people want to invest in an expensive aquarium heater that breaks down quickly.
We’ve reviewed the top aquarium heaters on the market so you can pick the best one to meet the needs of your tank. Check them out below.
A Quick Look at Our Favorites in 2023
|Best Overall||Fluval Submersible Glass Aquarium Heater||
|Best Value||Tetra HT10 Submersible Aquarium Heater & Thermostat||
|Premium Choice||Cobalt Aquatics Electronic Neo-Therm Pro Submersible Heater||
|Eheim Jager Thermostat Aquarium Heater||
|Aqueon Pro Aquarium Heater||
The 10 Best Aquarium Heaters
1. Fluval Submersible Glass Aquarium Heater – Best Overall
The Fluval Submersible Glass Aquarium Heater is the overall best aquarium heater. This budget-friendly heater is 50 watts, so it’s appropriate for tanks up to 15 gallons. It can be used in freshwater and saltwater setups. It has an adjustable temperature between 68°F and 86°F.
It features a reflective casing that makes it virtually invisible within your tank, and it has dual suction cups for a secure installation. It’s encased in shock-resistant borosilicate glass, so the chances of this heater being broken if dropped in your tank are slim.
Although it’s intended for small tanks, this heater is 11 inches tall, so it is too tall to be used in some smaller aquariums. It’s necessary for safe, proper functionality for the heater to be fully submerged.
2. Tetra HT10 Submersible Aquarium Heater & Thermostat – Best Value
The Tetra HT10 Submersible Aquarium Heater & Thermostat is the best aquarium heater for the money, so you can expect a very budget-friendly price for this heater. This 50-watt heater is suitable for tanks up to 10 gallons, and it’s only 7.2 inches tall, so it’s short enough for most nano tanks and is easy to hide behind plants and tank decor.
This low-voltage heater maintains your tank’s temperature at 78°F, but the temperature cannot be adjusted. The indicator light turns green when the heater is in standby mode, and it shifts to red when the heater is running.
3. Cobalt Aquatics Electronic Neo-Therm Pro Submersible Heater – Premium Choice
|Wattage||25, 50, 75, 100, 150, 200|
The Cobalt Aquatics Electronic Neo-Therm Pro Submersible Heater is the premium aquarium heater pick. It’s available in six wattages from 25 watts to 200 watts, so there is a heater suitable for tanks between 6 gallons and 55 gallons. The flat design of this heater allows it to be easily hidden, and it’s seated in a shatterproof case.
It features an LED display that shows both the set temperature and the current water temperature within the aquarium. This heater’s thermostat is accurate within 0.5 degrees, and it has a built-in thermal protection circuit that forces it to shut down if it begins to overheat.
4. Eheim Jager Thermostat Aquarium Heater
|Wattage||50, 75, 100, 125, 150, 200, 250, 300|
The Eheim Jager Thermostat Aquarium Heater retails for a mid-range price, and it’s available in eight wattages for tanks from 5 gallons to 265 gallons, making it suitable for most home aquariums. It can be adjusted between 65°F and 93°F, and it sits inside of a special lab glass jacket that ensures even heating throughout the tank.
It has double suction cups for secure, easy installation, and it features an automatic shutoff feature that turns the heater off if it detects it is no longer in water, decreasing the risk of explosion and fires. Some users of this heater have reported varying levels of accuracy in the temperature.
5. Aqueon Pro Aquarium Heater
|Wattage||50, 100, 150, 200, 300|
The Aqueon Pro Aquarium Heater is available in five wattages from 50 watts to 300 watts, and there is a size suitable for tanks between 20 gallons and 100 gallons. The temperature can be adjusted between 68–88°F, and it’s easy to adjust via a twist dial, which ensures precision. The temperature is accurate to within 1 degree, so you can feel comfortable about putting this in the tank.
The shatter-proof construction ensures safety, and the LED indicator light turns red when heating and green when in standby mode. This heater retails for a premium price, even for the smallest size.
6. Eheim Thermocontrol E Fish Heater
|Wattage||75, 100, 150, 200, 250, 300|
The Eheim Thermocontrol E Fish Heater is a submersible heater that is available in six wattages from 75 watts to 300 watts, and it’s suitable for tanks from 26 gallons to 100 gallons. This heater has a power cord that is 5.5 feet long, so you can plug it in safely away from your aquarium.
The indicator light turns red when running and green when on standby, and the heater itself is impact resistant. It features a temperature dial that is easy to use, and it can be adjusted from 68°F–90°F. These heaters do retail for a premium price, regardless of size.
7. Lifegard Pre-Set Quartz Glass Heater
|Wattage||25, 50, 100|
The Lifegard Pre-Set Quartz Glass Heater is a budget-friendly heater that is available in three wattages of 25 watts, 50 watts, and 100 watts. There is a heater available for tanks from 10 gallons to 45 gallons. This is a pre-set aquarium heater, so the heat cannot be adjusted from 78°F.
The thermal protection circuitry automatically shuts the heater down if it is malfunctioning to keep your tank inhabitants safe. It uses suction cup brackets for an easy, custom installation, and it uses an indicator light to let you know when it’s heating and when it’s in standby mode.
8. Aquatop Submersible Glass Heater
|Wattage||50, 75, 100, 150, 200, 250, 300|
The Aquatop Submersible Glass Heater is available in seven wattages from 50 watts to 300 watts, and it’s suitable for tanks from 13 gallons to 75 gallons. It features an analog view with an easy-to-use dial thermostat, and it has an indicator light to let you know when it’s running and when it’s in standby. It has a slim profile to minimize its appearance within the tank.
The double insulation glass and over-wind protection knob both work together to keep the heater functional and safe for your tank. This heater does need to be installed somewhat high up in the tank, but it should always be underwater up to the fill marking, so there is a small range in which this should be kept.
9. Penn-Plax Cascade Preset Submersible Aquarium Heater
The Penn-Plax Cascade Preset Submersible Aquarium Heater is available in two wattages, and it’s designed for medium tanks up to 20 gallons. It’s moderately priced, and while it comes programmed to 76°F, it can be adjusted within a wide range of temperatures. It offers accuracy to within 1 degree, and the temperature is easy to adjust with the twist dial and analog display.
It’s made from heavy-duty, shock-resistant glass, providing thorough and even heat distribution throughout the tank. This heater does have a small window of space between the required water level and the top portion of the heater, which is recommended to have out of the water.
10. Hydor Betta & Betta Bowl Slim Fish Heater
|Type||Submersible, under gravel|
The Hydor Betta & Betta Bowl Slim Fish Heater has a wattage of 7.5 watts, so it isn’t suitable for bowls or tanks larger than 5 gallons. It can be used in glass, acrylic, and plastic tanks, and it can be used as a normal submersible heater, or it can be placed underneath the tank gravel to heat from the bottom up.
This heater cannot be adjusted, but it is designed to keep the tank’s temperature slightly above room temperature, making it ideal for Bettas and other fish that require moderately warm water. It retails for a premium price, especially since it is only for very small tanks and bowls.
Buyer’s Guide: How to Select the Best Aquarium Heater
There are a handful of factors you should consider when selecting a heater for your aquarium. The first is the size of your tank and the wattage of the heater. A heater with wattage too low for your tank won’t be able to evenly heat your tank. It may end up wearing out more quickly because it will likely run more frequently in an attempt to reach and maintain the appropriate temperature. Buying a heater that is too large for your tank is unlikely to heat too much, but it is more expensive and will take up more space than an appropriately sized heater.
You also need to consider the type of tank layout you have. While all of the heaters on this list are submersible or under gravel, there are also heaters that are built into filters or that can be added to the water lines for an external filtration system. You don’t just need to consider the size and shape of your tank or the filtration system, though. You’ll also need to consider the available space within your tank. Heavily planted or decorated tanks may need certain heater shapes or sizes to fit the available space.
Also, keep in mind that not all submersible heaters can be placed straight up and down or laid on the side. Some can only be placed up and down, while others can be placed one way or the other. Some can even be placed at an angle, but not all of them can.
These reviews of the top aquarium heaters are a great starting point to help you find the perfect heater for your tank, without wasting time and money. Our top pick for the best aquarium heater is the Fluval Submersible Glass Aquarium Heater, which is adjustable and easy to camouflage within the tank.
The most budget-friendly pick is the Tetra HT10 Submersible Aquarium Heater & Thermostat, which is also short enough for most nano tanks. The top premium aquarium heater is the Cobalt Aquatics Electronic Neo-Therm Pro Submersible Heater, which is made with high quality and is available in six wattages.