Selecting Heaters For Your Freshwater Aquarium

Your aquarium will require a heater to keep the water temperature consistent and provide the optimum conditions for your fish and plants. Like most aquarium equipment, heater types vary in size, efficiency and performance.

Heaters vary in size, wattage and components such as the heater core and heating element. In general, you will need 3 to 5 watts of power to heat each gallon of water. A 50-gallon tank will require a heater of 150 watts or slightly larger. A 100-gallon tank will require a heater of 300 watts and so on. Very large tanks may require more than one unit. When shopping for heaters consider several factors. Heaters are generally of two types, submersible and over-the tank.

Submersible Heaters. These heaters are slimmer and less noticeable than the over-the-tank types. They come in a variety of lengths to accommodate deeper tanks. Their main advantage is that they are sealed to prevent water from seeping into the chamber that houses the element and heater core. They are held in place on the tank wall by a suction attachment and can be camouflaged by plants or rocks.

• Over-the-Tank Heaters. This type of heater is clamped to the tank wall by a plastic screw that holds it close to the rim of the tank top. The heat control is protected under a plastic cover that prevents the heat setting from being accidentally changed.