Which fish aquarium heater is the right one for your tank and why is it needed? Heaters provide consistent temperatures for tropical fish. The right size and type of aquarium heater depends on the size of tank, the requirements of the fish, and the location or placement of the heater in the system. In their natural environment, the water and sunlight maintain fish body temperature. But in the home or office aquarium, an electric adjustable heater is necessary to keep a constant temperature so your fish will thrive.
A temperature of 76 degrees to 79 degrees Fahrenheit will keep your fish healthy and comfortable. Heating an aquarium results in less temperature fluctuations. Swings in temperature can cause stress in fish and that can ultimately lead to sick or even dead fish.
Nearly every heater fish aquariums use is shaped like a long tube. The length typically matches the wattage of the tube heater. Short heaters are, for the most part, lower wattage while longer heaters can be rated as high as 300 watts. The vast majority of heaters are made of a glass or shatterproof plastic outer tube enclosing the electronic thermostat and heating elements and cores. Higher wattage heaters are available but aren’t normally stocked by local fish stores. Most of these are made from a titanium alloy.
There are two main types of heaters that are used in aquariums. Hang on heaters are not fully submersible and most of the time they are used on small freshwater tanks. They are normally 50w heating units or less that utilize a bracket to keep the adjustable dial out of the water. Never use hang on heaters with saltwater aquariums because of the possibility of “salt creep” that can cause electrical issues including shock. Submersible aquarium heaters can be fully submerged in the aquarium and placed vertically or horizontally. Many systems will use heater modules that are inline with the filter pump to keep the heater completely out of the aquarium. Often this is needed when you don’t want to see the heater or if you have large fish that are prone to get too rough and could possibly break the heater inside the tank. Oscars, green terrors and arowanas are famous for breaking heaters. Most wet dry systems have plenty of space to put a submersible heater as well.