The Best Aquarium Heaters in 2022

Used alone for smaller tanks or in a pair for tanks above 10 gallons, the Tetra HT is a well-priced product that scoops top spot in our best aquarium heaters guide. As a 50W, fully submersible heater, it’s easy to use and can be installed either vertically or horizontally. It also has a built-in thermostat, set to 78°F so you can be sure the water is the right temperature for your fish, without having to re-set to ensure the tank is in the ‘safe zone’. Add in an indicator light, so you know at a glance whether it’s heating or maintaining the water temperature and this is a low-maintenance aquarium heater that can easily be concealed although it does need to be used in conjunction with a tank hood or lid.

Coming in at 300W, this submersible heater from Orlushy is suitable for tanks up to 80 gallons and is fully adjustable thanks to the temperature dial which covers 68 to 89°F temperature range. Safe for both saltwater and freshwater , the unit is also fully submersible, with the temperature control hanging over the side. The thermostat is housed in 2mm thickened quartz glass for safety and works to maintain a constant temperature, including an auto shut off when the desired temperature is reached. The heater itself is sleek and modern and you also get a 6ft power cord to give you flexibility as to where your aquarium is located.

For use in freshwater or saltwater aquariums up to 100 gallons, the 300W Fluval is a high-tech heater that gives you precise control over the temperature inside your tank. This digital aquarium heater can be adjusted to within 0.5° increments and will continually monitor and display the water temperature via its easy to read LCD display. The temperature range is impressive too – 68-93°F – and with fast heat technology and safety shut off as well as a built-in fish guard, you can be sure your fish are safe and happy. Easy to fit, we also like the included bracket, which means you can position the heater inside the tank at any angle for the perfect view of the display.

The 50W Freesea is ideal for smaller tanks as it is neat and easy to use. The heater has a built-in thermometer and simply needs to be hung over the side of the tank until it is fully submerged. Once under the water, the temperature reading is continually displayed, thanks to the large LED display. Outside of the tank you have your small control panel, with touch button control to adjust the temperature. With a range of 59 to 94°F, this is a versatile little heater too. Add in an auto constant temperature function, which will stop when it reaches the desired temperature and kick back in when the water starts to cool, and you have a smart little heater for your one to 10-gallon aquarium.

Betta fish are one of the most popular for home fish tanks but as they are notoriously territorial, are often better kept solo. Which means their aquariums tend to be on the smaller side, which makes these submersible heaters a great value choice. Designed for tanks up to 1.5 gallons, this 8-watt heater is going to keep your betta happy. The design is simple and that’s its beauty – simply stick to the inside of the tank and let it heat up the water to the set temperature. The red indicator light lets you know when it’s heating and the whole unit is made from tough polymer for a long-lasting mini aquarium heater.

Shatterproof, this fresh or saltwater heater from Hygger features a corrosion-resistant titanium body for extra strength, safety and durability. Sized for tanks between 10 and 25 gallons, the 100W heater has a built-in thermometer and is easy to mount but must be submerged horizontally next to the filter. Setting and managing the Hygger is slick, thanks to the external control panel which features a dual LCD display that can be set to either Celsius or Fahrenheit. You also get a wide temperature range, from 32 to 104°F with an accuracy of +/- 0.5° C. Add in an auto shut off when it the required temperature and you have a high-performing aquarium heater for your money.

This hang-on immersible heater is made from titanium to prevent corrosion and will bring your aquarium up to temperature in speedy time. And once there, it works to maintain the water temperature to within +/-2ºF. A good choice for both salt and freshwater, the 150W Finnex is sized for tanks between 30 and 60 gallons. And the slim heating element means it’s pretty easy to hide. You then simply hang the attached control panel – which comes complete with LED indicator, so you know when it is heating – over the side.

With the heating element encased in break-resistant quartz, this fish tank heater is both neat and durable and is a good choice for either fresh or saltwater aquariums. The ViaAqua needs to be fully under the water but the slimline design means it doesn’t take up too much space. And with 300W of heating power, is good enough to be used in larger tanks. The temperature gauge is built in and easily visible under water and the temp adjustment dial is situated on the top for easy access. The ceramic core of the heater is a nice touch as it helps with the even distribution of heat and you also get a red indicator light, so you know exactly when it is working.

Our premium pick is this well-designed Neo-Therm Heater from Cobalt Aquatics, which offers energy efficient heating of tanks up to 29 gallons. The flat design works well inside the aquarium and it’s fully submersible for maximum impact. With its reversible bracket it can face inward or outward, depending on your tank set up and is one of the most accurate heaters in our review. With a thermostat accurate to within +0.5°F, it also has a set temperature range of 66ºF to 96ºF so ideal for most fresh and saltwater aquariums. You also get a one-touch system to control the heat, with both the set temp and the current water temperature clearly displayed. Add in the safety of a shutdown system and you have a heater that deserves its premium title.

Unlike the other heaters in our review, the ISTA is an in-line external heater which sits inside the filter or sump and doesn’t take up any space inside the tank. The heating power is 500W so a good consideration for larger aquariums and can be used with either salt and freshwater. This heater also has two temperature sensors to check the water as it goes through the inlet and outlet for a more consistent temperature throughout. The thermal glass design also heats up the water faster and the temperature is clearly displayed on the external control. Shown in Celsius, you get both the set temperature and the temperature in real time, so you always know what is happening inside your aquarium.