If the tank is regularly exposed to temperatures more than the desired maximum temperature, cooling may be necessary. Purpose built chillers can be purchased and many also have heating capabilities. As with heaters, you need to ensure the unit is able to cope with the change in temperature (between ambient and desired tank temperature) and with the tank volume. There are some DIY chiller plans available on the web.

If the ambient temperature is only slightly more than the desired tank temperature for short periods, cooling fans are usually more than adequate. A cooling fan blows air over an open expanse of tank water and evaporation cools the water. See: Cooling Fans for more details.

Last updated: October 16, 2002