Will it make a difference if I change the zones on my time to run 2 15 minute waterings rather than 1 30 min watering? Right now it is set to run twice a week for 30 min per zone. I am being asked to change it to 4 times per week (same days) for 15 min per zone. I can't find any good reason to do this. It's for 2 18 zone panels.