First of all, DO NOT RELY ON YOUR SPRINKLER SYSTEM!!!!! Relying on the sprinkler means you are not checking the soil moisture, and probably not watering enough, which voids your warrantee. Turn on the hose (we know that getting up to do it is the hard part). The flow coming out of the hose should be between a trickle and full blast. It should be strong enough to get the job done, but not strong enough to move the soil. Now, go inside and set the timer on your watch, oven, or computer (your can down load a timer) for 30 minutes. When the alarm goes off….turn the water off and mark your calendar, so you know when you last watered.