Evapotranspiration is the amount of water that is lost from the soil through evaporation and plant use. As the days get longer and warmer from March to August, E.T., or the plant's need for water, gradually increases. Besides the length of day, temperature, humidity, and rainfall all are factored into watering schedules. When rain usually ends in March, irrigation controllers traditionally are turned on and then left running on a preset schedule until well into the fall when it begins raining again. This schedule waters too much on some days and not enough on others, either wasting water or causing plant stress. More efficient irrigation scheduling would read just the system run times to match the changing plant water needs daily, and would water less as days get cooler and shorter in the fall.

E.T. irrigation controllers re-adjust themselves automatically as often as needed without manual reprogramming by using three sources of information: 1. Built in logic has solar radiation values for every micro climate, permanently stored onboard in memory, by postal zip code or latitude. 2. Entered data about each zone to be watered: soil type, plant type, irrigation type (sprinklers or drip), and slope. 3. Real-time data from on-site sensors or wireless E.T. weather data service enabling fast response to unexpected storms or heat waves.

To deliver on these revolutionary water-saving promises, E.T. controllers require correct set-up with site & product specific input. After they are correctly installed and programmed, these controllers operate trouble free, delivering only the amount of water needed by the plants every day, through the wet and dry season, without waste. The Urban Farmer Store is a trained, certified, and authorized distributor of Hunter Solar Sync, Hunter ET System, Weathermatic’s Smart-Line®, Irritrol’s Smart Dial® ET controllers, Aquairus Acclima & etWater

Contractors and homeowners can learn how to properly set up these controllers from the Urban Farmer Store. Marin Municipal Water District and EBMUD may offer rebates and incentives directly to water customers who install these E.T. controller. Check the EBMUD or MMWD Marin Municipal Water District websites for detials.