Aquatic Flat Heater - 7.5 W Specifically designed for small aquariums, the Aqueon Aquatic Flat Heater takes up very little space while ensuring your water is warmed efficiently. Ideal for use in small desktop aquariums up to 3 gallons in size, energy-efficient heater is fully submersible and consumes a mere 7.5 watts! With the use of the included suction cups you can easily and quickly install it on the sides or bottom of your aquarium. 5.5" x 2" x 0.5"