Aquarium heaters for tropical fish

When it comes to water, some fish like it hot. Or, to be more precise, some like it lukewarm. If you plan to keep tropical species, you'll need to maintain a temperature in the tank of about 78 degrees Fahrenheit--but depending on the kind of fish you choose, the optimum temperature may range somewhere between 74 and 84 degrees. The temperature in your tank can be easily maintained with a good-quality, thermostatically -controlled heater of the correct wattage.

Aquarium heaters

The most common aquarium heaters feature an electric element enclosed in a water-tight glass tube. Should the water drop below the desired temperature, the thermostat will automatically turn on the heating coil. You'll find models featuring an internal thermostat contained within the glass tube, as well as those with external thermostats that must be attached to the outside of the tank. Combined units are a lot easier to connect, but whichever type you select, you'll need to make sure that the part of the tube that contains the heating element stays clear of gravel and says submerged; this allows for optimum water circulation.

It's essential that you purchase the right size heater for your tank. The standard rule of thumb is 5 watts of power per gallon of water, although some experts contend that 3 watts per gallon is more than sufficient. You may want to ask at your aquarium store for a recommendation. Also note that in larger tanks of more than three feet long, you'll get a more even distribution of heat if you divide the work between two separate units.

Fish tank heaters and thermometers

An inexpensive aquarium thermometer will allow you to easily check that the water temperature remains at a constant. There are many types available. Floating thermometers attach to the inside of the tank with suction pads, and there are also several models that stick to the outside of the glass. If you get the liquid crystal kind, be sure to install it on the shady part of the tank, as direct sunlight can affect the reading.

When you first add the heater to your set-up, it is recommended that you set the temperature at a low reading and gradually work up to the required temperature; it will help to use your thermometer as a guide. Once the water's perfect, keep it there--and keep it stable. Sudden changes in temperature can severely stress your fish.