I am tapping a new irrigation system into my main household water line. I have a 3/4" meter and main line coming into my crawlspace. It is immediately reduced to a 1/2" line running to the water heater then dispersed thruout the house. I want to know if I can tap into the 3/4" section before the reduction giving more flow to the irrigation but not effect the flow to the household fixtures or do I have to tap into the line after the reduction and use a 1/2" feed to the irrigation.
No matter which way you do it the flow will be the same depending on the type, number and size of the sprinkler heads.
The main run lines in the house and the supplys in and out of the water heater should have all been 3/4" not 1/2.
When those sprinklers come on the pressure and flow will drop like a rock.