my street water pressure is around 100 psi, my house pressure has a regulator on 70 psi. my yard sprinkler system is directly on my street water line before the house. I want to place pressure reducers at each of four zone valve locations as I cannot access the main line to the water yard sprinkler system. What in line pressure regulator setting should I use? same for yard lawn pop ups? how about a small zone with only droppers?