I'm trying to figure out watering need for the area in front of our house which has bermuda grass. According to several websites the weekly need is 0.49" to 0.75". Let's say its 0.5"/week. The area is 1600m2 (or 17200 sq.ft). I have a sprinkler which sprays a radius of 14 meters and i measured it filled a 525 us gal tank (in which the sprinkler had been left on) in 2 hours so 262.5 gal/hr. To allow 0.5" of water to cover this circle of 14 meter radius, my math says I need to let it run for jusdt under 7 hours ?! Can this be correct ? Thanks in advance