What is an “ET” timer?
The short answer is that it is a timer that is controlled automatically by the local weather. ET stands for evapotranspiration, which is the amount of water in the soil that is lost to evaporation. CIMIS (see their website) keeps a record of this info. These timers use technology that pools information from local weather stations and CIMIS to determine how much and when to water. When the timer is first installed it is adjusted for many factors, including plant type, sun vs. shade, slope, soil type, drip vs. sprinkler and more. Once set up by EarthCare they can be adjusted easily in 5% increments by the client if necessary. There is currently about a $4/monthly fee for the technology, which is paid to the company that services the controller, not to EarthCare.
