Using Thermometers in Your Aquarium

By encasing the heater and thermostat in separate tubes, one is enabled to place the heater in one corner and the thermostat in another. This is supposed to insure a more even distribution of heat, since the heat must travel through the entire tank to reach the thermostat. In theory it is all right, but in actual practice it has hardly proven necessary. Water circulation itself distributes the heat readily enough.

Any type of thermometer can be used in a fish tank that is partitioned into several sections. Judge the wattage required by the capacity of the tank. Place the thermostat and heater in the center section or in adjoining sections. The end sections may be a few degrees cooler than the center, but the difference will not be appreciable.

To make sure that your thermometer is giving the correct reading, place your thermometer alternately in warm and cold water to see if it rises and falls properly. Wash the thermometer carefully, and place the bulb edge under your tongue. An accurate thermometer will read close to 98.6° F., which is body temperature. A variance of 2° or 3° is not important, however, since aquarium temperatures are not that critical.

Check a new thermometer for breaks or spaces in the mercury or “spirit” column. These often occur because of jostling during transit. To eliminate such breaks, place the thermometer on a piece of ice until the indicator has retracted completely into the bulb. When the indicator fluid is allowed to warm up, the column should be continuous.