Calibrating Your Irrigation System

Calibrating sprinklers on campus, photo by Michael Gutierrez, UF/IFASPhoto by Michael Gutierrez, UF/IFAS

Calibrating your sprinkler system means figuring out how long you need to run your sprinkler system to apply the correct amount of water. In most Florida soils, the correct amount is 1/2 to 3/4 inches of water. This rate varies depending on your location in the state. Heavier clay soils, such as in North Florida and the panhandle, may only need the 1/2-inch rate. In sandy soil, which doesn't hold water as long, you may need to apply the 3/4-inch rate.

Set out five to ten coffee or tuna fish cans (any straight-sided can will do) around your lawn. If you have an in-ground irrigation system with multiple zones, place the containers in one zone at a time. Scatter the cans at random within the zone. Repeat the procedure in every zone, because there may be differences in how uniformly water is applied in each zone.

If you use a hose-end sprinkler to water your turf, place the cans in a straight line from the sprinkler to the edge of the watering pattern. Space the containers evenly.

Turn on the sprinkler system for fifteen minutes. Then use a ruler to measure the depth of water in each container. The more precise your measurement, the better your calibration will be.

Find the average depth of water collected in the containers. To do this, add up the depths in the different containers and divide that number by the number of containers. This will give you the correct rate in inches per fifteen minutes.

To determine the irrigation rate in inches per hour, multiply the above number times four.

Calibrating your system helps you save water and money and protect your grass and plants from disease. For more information about this and many other gardening topics, contact your county Extension office.