Timing of Sprinkling and Measuring

TL;DR

1. Read the water meter before the sprinkling for the day. If irrigation begins late at night and crosses into the next day all of the volume is counted for the day irrigation started.

2. Make sure the App has the correct value for "Days to Water" and "Percentage Adjustment". These are the controllable settings App will compute to target a specific month end total.

3. More than one sprinkler program can run on a day, but every day must run the same programs (or be a dry day).

4. Adjusting individual zone run times will render target calculations incorrect to some degree, but over more days the calculations will make the corrections.

5. Ad hoc watering will also affect target adjustments, but consistent ad hoc watering will have minimal effect.

If it important to use monthly usage prediction then certain rules must be followed for these future predictions to be accurate. Essentially this boils down to a consistent gallons per run cycle, with a run cycle occurring inside a 24 period. The only sprinkling parameters that can change are the days of week (so called wet days) sprinkling runs, and a percentage setting that allows the runtime to be adjusted for the time of season.

The accuracy of gallons measured numbers are not affected by changes, but if past history in a month is used to adjust wet days and more often percentage then it is important that these values are reflected correctly when gallons value is entered. This allows the App to predict where you will end up at the month end, and with a known enforced limit of usage the App can predict what the percentage show be set to to hit this target.

This is done by computing the gallons per day at 100% based on the early month history, and this is what requires that system adjustments must be made after the gallons are entered. With a suggested change this new setting for wet days and percentage must be made before the system runs the next cycle.

In other words, the wet days and percent App settings must reflect the settings when the measurement is made. This may be one or more days following actual change, and at that point another suggested change can be made. These subsequent adjustments should get smaller and with fewer days left in the month the days of extrapolation are less, and the prediction should be more accurate.

One uncontrollable is water pressure and changes over the month will always reduce the accuracy of the monthly usage prediction.