Hi js,

WOW! This is one of those puzzles that has more unknowns than equations. How many irrigation zones? What is the flow rates and time for the sprinklers to max out? What is the capacity or size of the 3 tanks? How are the tanks hooked into the system? How much peak flow do you need for your house, if everyone flushed, brushed there teeth, did the laundry and washed the dishes at once? When does your geothermal pumps need to be running? Is the lawn split up into sections like front, back, side to side? What type of plants do you have in the beds? 1" of water for 100 sf of lawn per week is 63 gallons. Times 150 for your 15,000 sf is 9,450 gallons each week plus or minus for seasonal changes. Water your lawn and vegetables at night when you are asleep. Do a 24 hour matrix scheduling the quantities for all your uses and storage. Your pump designer/installer should be able to make sense of it all. Good luck. Aloha