This is a valve that prevents the accidental backflow of water in the system getting into the water line. This may be required by city ordinance in some municipalities. Considering the minor cost, it is probably a wise investment for anyone considering a system. A timing device can be added to automatically turn the system on and off. This can be as simple as a battery operated attachment or a more permanent timer that is wired into your electrical system.
Plastic tubing is used to get the water from the source to the garden.
This comes in many sizes. A variety of fittings are available to go around corners and to connect pieces. Plastic tubing considerations 1. Check with the supplier for the maximum length of tubing that can be run in any one direction. Consider what you intend to water with the drip system.