An irrigation controller is the clock that runs a sprinkler system. A good controller can make the difference between a landscape that is efficiently managed and one that is not. It can also have a strong effect on a business's monthly water bill.
Property managers who inadvertently water their landscapes too much or at inappropriate times of the day nearly always end up with high water bills. The newer controllers, like Hunter or Toto irrigation controllers, take into account local weather conditions. They make it easier to have a healthy landscape and a healthier water bill, too.
Really large sprinkler systems may have more than one controller. Each controller has several stations (timers), depending on its size, that control different parts of the landscape, each station with its own timer. Older controllers and their stations are programmed by hand, with the landscaper guessing https://www.youtube.com/watch?v=Khx Cu6cQBMs how much water each section will need. Newer ones take weather and other factors into account, modifying programmed schedules to water only when plants are thirsting.
What are Weather Based Irrigation Controllers?
There are several different kinds of "Weather Based Irrigation Controllers" (WBIC) or Smart Controllers, and all of them work by using input about the site from local sensors or satellite weather stations to modify the watering schedule. Examples of information WBIC's can take into account are: Weather readings, moisture in the air, moisture in the soil, solar radiation, plant types, soil types, slopes, and water pressure. Each of these factors affects the amount of water needed by plants in a landscape, and alters the amount of water the controller will allow through the sprinkler system.
How a controller works.
Each controller has several stations hooked up to valves that feed water to sets of sprinklers in different locations or zones. Controller sizes can vary from four to 200 stations, each with its own timing. Since stations are designed to match the watering needs of whatever plants are in its relevant zone, having a number of them provides a lot of flexibility with watering.
The size and number of controllers chosen for a sprinkler system depends on the size and complexity of the landscape. As mentioned, each landscape zone is watered by sprinklers controlled by a valve. Station timers control the valves and controllers host the stations. Since controllers/stations are hooked up electronically to the valves, they have to be located near enough to allow for a hookup.
A six acre site with valves spread out through the landscape with many different types of plantings could have 8 controllers with 64 stations each, whereas a one acre landscape may need only one or two controllers with 8 stations each. A station could be set up to water trees and bushes on one side, another for grass in front, a third for a drought tolerant section, another for medians or parkway, one for a shady section, or another for grass in a far corner.
Without thinking, most people schedule their sprinkler systems to water flat turf, whether or not it's best for the other types of plantings there.
Watering on http://www.hgtv.com/design/topics/lawn-care a slope is tricky. You want to water so it sinks in, but doesn't run off. That means scheduling your controller for short run times several times in a row, so water has a chance to sink down between times.
Native plants need hardly any watering. That section of the landscape needs a station of its own, with its own watering schedule, or the plants will be overwatered and die. | Source
Controllers vs. nozzles.
There are some situations in which problems with watering have been blamed on improper controller programming, when in fact that may not be the case. T he most common of these is really a problem with irrigation nozzles.
types of plants require different speeds and lengths of watering, and
so do different soils. For best watering, different plant types
should not be watered by the same station, nor should they be watered
by the same types of nozzles (see "Irrigation Nozzles").
Because different types of nozzles allow for different amounts of
water through them, if you mix them on the same station, you will
cause one area in a section to be either shorted or flooded.
reason a controller has a number of stations with their own timers is
so that a landscaper can take the difference in nozzles and plant
types https://www.youtube.com/watch?v=KhxCu6cQBMs into account when programming watering schedules. The stations
and their valves give much needed control. But a landscaper th at
bypasses that control by mixing nozzle types or plant types on the
same station loses the flexibility that a good controller gives.
WBIC scheduling assists - like rain & soil sensors.
When first installing a new WBIC, the landscaper will be entering the soil type, types of plants, water pressure, and location of property (latitude and longitude or zip code), among other data, as detailed by installation directions. Additional information will be provided by additional accessories that support more efficient watering with a WBIC:
Purchasing a WBIC.
The type of Smart Controller you choose to buy will depend on conditions onsite. Here are some things to look for:
Is it user-friendly? Easy to understand and program?
Does it allow for sensors to be attached and read?
Here are a number of links that show different brands of Smart Controllers:
Enjoy the shopping, but remember that the real benefits of your new controllers will depend on how well you set up, test, and adjust them. Make sure you and/or your landscaper follow the controller's written instructions, then check the results several times afterward to make sure they are operating efficiently for the sprinkler system on your site.