I have added on to my existing sprinkler system and setup 3 new valves into my garden. I only ran 1 pvc line to the garden and the wiring needed to control the valves. I don't want to keep the pvc line to the garden permanently pressurized so I was hoping to use one of the valves near my house as a master valve. The rest of my system does not need a master valve. Is there a way to set the system up so the master valve will only turn on for 3 zones but not the rest of the zones? I have the rain machine touch hd12.