Top Submersible Aquarium Heaters

Too often an aquarium heater is thought of as a simple and inexpensive device. An aquarium heater, particularly for a saltwater aquarium, should be considered a critical piece of equipment, just like a filter that is essential to the livelihood of your tank inhabitants. One of the most efficient and popular types with aquarists are submersible, and here is our list of top pick units that have some of the best features one should look for when buying a heater for your aquarium. Aquarium heaters always make a great gift for the aquarist in your life.

  • 01 of 09

    Azoo Titanium Electronic Heaters

    Azoo Titanium Heater
    Photo from Amazon

    Virtually indestructible titanium alloy heaters feature a remote electronic thermostat for convenient aquarium temperature control. Built-in sensor shuts off heaters automatically when heating element leaves the water's surface. Power and heating indicator lights allow convenient monitoring of heater operation. Azoo Titanium Electronic Heaters feature a temperature control range of 21º-33º Celsius (69º-91º Fahrenheit) with ±1.0° Celsius accuracy. Fully submersible. Includes suction cups and mounting clip. For use in fresh or saltwater aquariums. Temperature control dial is in Celsius scale.

  • 02 of 09

    Eheim Jager Heaters

    Eheim Jager Submersible Aquarium Heaters. Photo from PriceGrabber

    Ehiem Jager heaters are submersible only to the water line mark on the unit. Ehiem Jager heaters feature an automatic dry run shut off, precise temperature control and temperature recalibration capabilities, are constructed of special Schott DURAN shatterproof glass, and have a heating function indicator. Available in sizes from 25 to 300 watts.

  • 03 of 09

    Fluval Series E Aquarium Heaters

    Fluval Series E Heaters.

    Fluval E Series heaters employ a digital microprocessor to continuously monitor and display aquarium water temperature. The internal thermal sensor continuously samples aquarium water temperature for greater accuracy and reliability. Innovative color-coded temperature alert feature changes LCD screen color if aquarium water temperature varies from the pre-set temperature (Green = Safe Zone, Red = High Temperature Alert, Blue = Low Temperature Alert). Easy-to-use adjustment lever allows precision temperature settings in 0.5° increments and integrated heater guard offers advanced protection for fish and invertebrates.

  • 04 of 09

    Hagen Tronic Electronic Heater

    Tronic Heaters
    Tronic Heaters. PriceGrabber

    A fully submersible unit with fast heat technology, while most heaters cycle on and off, the Tronic Electronic Heater by Hagen has a patented Thermo-Sensor that makes the heater's water sensor as accurate as a separate probe. Other features include a safety shut off, and solid state design that allows it to be positioned at any angle. Requires the use of the Tronic Heater Guard (not included) to safeguard the heater from damage, and prevent fish from coming into contact with it when in use.

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  • 05 of 09

    Hydor Theo Heater

    Hydor Theo Heaters
    Hydor Theo Heaters. PriceGrabber

    The Theo Heater works with a heating technology patented by Hydor. The heating element is made of a special polymer that has been silk printed with special ink, the ink heats up with the passing of electric current, and the heat is transferred to the water. Other features include special shatterproof glass, a precise temperature setting knob that clicks in 1°F increments, an on/off indicator lamp, and it switches itself off if the heater is not fully submersed to prevent overheating and damage.

  • 06 of 09

    Marineland Stealth Heaters

    Marineland Submersible Stealth Heaters. Photo from PriceGrabber

    One of the best features of the fully submersible Stealth Heaters by Marineline (Aquarium Systems) is the shatterproof plastic casing. Unlike other heaters constructed of glass, this covering not only protects the inside components against thermal and mechanical shock, but makes them extremely strong and durable. With a cylindrical core that distributes heat evenly throughout the heater, an easy to set temperature dial on top, and efficient overheat-protected operation, these units are at the top of our list. Available in 25 to 250 watt sizes to fit all freshwater or saltwater systems up to 75 gallons. If you have a large aquarium, just use two heaters.

  • 07 of 09

    Marineland Visi-Therm Deluxe Heaters

    Marineland Visi-Therm Deluxe Submersible Aquarium Heaters. Photo from PriceGrabber

    The water-calibrated thermostat of Visi-Therm Deluxe Heaters by Marineland are certified accurate to within one degree, ensuring precise temperature selection and superior performance. These advanced-compact design, durable glass constructed, double-sealed submersible aquarium heaters have a convenient temperature dial on top, a large, easy to read temperature setting window visible through the glass on the side, and an on/off light indicator. Available in sizes from 25 to 300 watts.

  • 08 of 09

    Tetra Whisper & HT Submersible Heaters

    Tetra Heaters
    Tetra Heaters. Photo by PriceGrabber

    The Whisper and HT model submersible heaters by Tetra are designed specifically for heating small aquariums of 2 to 30 gallons in size. Both models are durable and simple to operate, especially the HT units, because they have an electronic thermostat that automatically adjusts heat output to keep the water at a constant 78°F. All you have to do is put it in the aquarium and plug it in! If you need to heat a mini or nano reef tank, one of these Tetra heaters would be ideal.

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  • 09 of 09

    Titanium Heaters

    Azoo Titanium Aquarium Heater. Photo from PriceGrabber

    Titanium alloy heaters are virtually indestructible. They require a controlling device for operation, and although Azoo's Titanium Heater includes one, with other brands the controller is typically sold separately. Look for units that are designed to automatically shut off when the water level drops or they are exposed to air when plugged in. Most other types of submersible heaters only go up to 250 and 300 watts, but titanium heaters are available in higher wattages, such 500 and 800 watts, which are ideal for heating for larger aquariums. Titanium constructed heaters offer superior heat conduction and accuracy, are acid and corrosion resistance in fresh or saltwater.