How to Size an Aquarium Chiller

Maintaining the proper temperature in your aquarium and keeping it stable is required to keep aquarium inhabitants healthy. An unstable or incorrect temperature can cause stress, disease, algae and death in your fish. The specific temperature may depend on your fish or coral, but a good rule of thumb is 75 to 82 degrees Fahrenheit. If you live in a hot region or you use heat-producing aquarium equipment, such as metal halide lights, you likely will need to add a chiller to your aquarium setup to maintain the optimum temperature.

Things You'll Need

  • Water volume of tank
  • Water volume of sump
  • Current tank temperature
  • Desired tank temperature
  • Heat output of tank equipment
  • Manufacturer̵7;s sizing documentation
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Instructions

    • 1

      Choose the specific type and manufacturer of chiller you plan to install. Some types of chillers to consider include drop-in chillers, in-line chillers and thermoelectric chillers. Thermoelectric chillers are most suitable for small aquariums. Drop-in chillers are more variable and don̵7;t require as much space, and in-line chillers can support the largest of tanks. Most manufacturers provide specific ratings for their chillers, so it is important to do your sizing exercise based on the specific chiller you have chosen.

    • 2

      Calculate the water volume in your sump and tank. One of the factors in the size rating of the chiller is how big the aquarium is. The larger the aquarium, the more horsepower that is required for the chiller to maintain the proper temperature. You can find the water volume of the sump by checking the manufacturer's specifications. There are two ways to find the water volume of your tank. The easiest way is to use the tank size from the manufacturer, such as 90 gallons. If you know the dimensions of the tank, however, you can do the calculation manually: Multiply the length times the width times the height of the tank in inches and divide that number by 231 to get the volume in gallons. For example, a tank measuring 48 inches across the front, 15 inches from front to back, and 24 inches from top to bottom holds 75 gallons. If the tank is not rectangular, such as hexagonal or bowfront, use an average measurement. For example, if it is bowfront, measure the width in the middle and on the end, and average the two measurements.

    • 3

      Record the current temperature and desired temperature of your tank. A large variance between the current and desired temperature can be indicative of environmental variables that impact the temperature of the tank.

    • 4

      Record the heat, in wattage, put out by your aquarium equipment, including lights, pumps and power heads. To find the wattage your equipment produces, look on the equipment itself or in the documentation provided by the manufacturer. The combined heat put off by your aquarium equipment must be compensated by the chiller. Some equipment, including metal halide lights typically used in reef tanks, can put off a significant amount of heat.

    • 5

      Use documentation provided by the chiller manufacturers to determine the proper size chiller your tank requires. For example, JBJ Lighting has an online tool to help you calculate the chiller size required based on the facts gathered in Steps 2 through 4. Chillers are typically measured in horsepower.