Any irrigation system with a conventional irrigation controller can be upgraded to an unpowered system where each solenoid valve is replaced by ...

Any irrigation system with a conventional irrigation controller can be upgraded to an unpowered system where each solenoid valve is replaced by an Unpowered Irrigation Valve. The conventional irrigation controller and the associated wiring become redundant. Please watch the video "Unpowered Irrigation Valve"
https://www.youtube.com/watch?v=4PwyPALKwd0