A thermostat is a device for monitoring temperatures and switching devices on or off based on changes in temperature. Your home heating and air conditioning will have a thermostat to turn the heat on when it gets too cold and to turn it off again when your home has warmed up. Your refrigerator and oven also have thermostats to turn them on or off based on the temperature settings you select.

In an aquarium, a thermostat is necessary to properly and safely run a heater or chiller. By correctly setting your thermostat , you can properly maintain your aquarium temperature.

Most heaters and some chillers come with built-in thermostats, so you have a control right on the heater or chiller to set the thermostat to maintain the desired temperature.

Some heaters and chillers come with a remote thermostat which is separate from the heater element or chiller and is placed in a different location in the aquarium. Heaters and chillers with remote thermostats like this tend to do a better job of maintaining an even and consistent aquarium temperature. However, it is usually not necessary to keep a very exact temperature in your aquarium, as water temperatures in nature tend to fluctuate over time. It is, though, important to be familiar with the species and varieties of fish you are keeping to know how much temperature fluctuation they are likely to tolerate....