Tetra Submersible Aquarium Heaters - Fish Tank Water Heater & Aquarium Water Heater selection at petco.com Keep your fishy friends happy and comfortable with Tetra Submersible Aquarium Heaters. This aquarium water heater line is ideal for use in small to medium tropical tanks or for tanks in rooms with a relatively cold air temperature. The low profile Tetra fish tank water heater measures just 6.5" long - absolutely ideal for placement anywhere in your tank. The compact design keeps it out of sight concealed behind any aquarium d,cor or in a corner of the tank with good circulation.A suction cup keeps the aquarium water heater securely in place against the inside of the tank. As a fully submersible heater, it can be placed anywhere in your aquarium so you can conveniently run the power supply to your nearest outlet. Tetra Submersible Aquarium Heaters are efficient and hassle-free. Once set, your fish tank water heater will heat your aquarium and maintain a constant temperature of 780F - ideal for most tropical fish. You will not need to adjust the electronic thermostat once you install the aquarium water heater in your tank. Convenient features and a sleek design make Tetra Submersible Aquarium Heaters very easy to use. Simply install in your tank, plug in the power supply, and let it run! The fish tank water heater's indicator light will tell you if the heater is actively heating the water or if the water has reached the desired temperature. Enjoy a happy and healthy tropical fish tank by using the Tetra Submersible Heater. It is the fast and easy solution to your tank-heating needs!