top of page

The Marineland Precision Submersible Aquarium Heater offers safe, reliable, highly accurate heating for your fresh or saltwater aquarium. A built-in thermal safety switch accurately regulates the temperature to within 1 degree. The switch also automatically turns the heater off if temperatures exceed internal parameters, and turns it back on when the tank temperature returns to normal. Top and side view temperature scales allow easy viewing from all angles.

  • Maintains precise aquarium temperatures to within 1°F accuracy
  • Thermal safety switch turns off automatically to prevent heater failure
  • Suitable for fresh and saltwater aquariums

The Marineland Precision Heater is extremely user-friendly, with an abundance of features to enhance convenience. The combination of a top-view scale and high visibility sliding scale provides dual confirmation of all temperature adjustments. The "Click Set" control knob clicks for every degree you change the temperature for easy, precise heating. This heater is built to last, with an advanced mesh heating element surrounding the mica core for enhanced heat transfer and long lasting, reliable performance. UL listed.

Included with the Precision Heater is an advanced mounting bracket that securely attaches to glass, providing 3 window positions that let you view the temperature display from multiple angles.

100 Watt: 10.25" Long; Aquariums up to 29 Gallons
150 Watt: 12" Long; Aquariums up to 40 Gallons
200 Watt: 13.5" Long; Aqauriums up to 55 Gallons
250 Watt: 14.5" Long; Aquariums up to 70 Gallons
300 Watt: 15" Long; Aquariums up to 80 Gallons
400 Watt: 18" Long; Aquariums up to 125 Gallons


  • Attach the included Suction Cups to the Double Suction Mounting Bracket. Slide Bracket over heater.
  • Place heater in aquarium by firmly pressing suction ends against wall surface. The Three Position Viewing Window allows you to view the temperature setting from three possible angles - simply turn the heater until it locks into the best viewing position. NOTE: Choose an algae-free location with adequate circulation. This ensures even heat distribution and optimum operation. No part of the heater housing should contact aquarium gravel, rocks, or decorations.
  • Wait at least 15 minutes before plugging in your heater. The ON/Off Indicator Light will confirm that the power is on. NOTE: Before plugging in heater, create a "drip loop" to prevent water from reaching receptacle.
  • Select the desired temperature. Turn the "Click Set" Temp Select Dial until the point of the red line on the thermometer scale reaches the correct setting. Most tropical fish like 78°-81°F water.

It is recommended to use a tank cover to prevent water temperature variances or heat loss. Both can impair heater performances, creating a hazardous environment for the fish.

Marineland Precision Submersible Aquarium Heater