Take the 2-minute tour ×  I'm going to automate the bottom
watering process (reservoir and wick method). This design should
uses a water float valve instead of a timer. What is the best
way to do this? Here are two methods:  Use a full-pressure water
float value and use one of those steel covered hoses made for
the washer/dryer. Connect that to a float value in an enclosure.
The water will be siphoned off to all the plant sitting at the
same water level as the float valve. The washer dryer hoses can
come with a safety cut-off if the water flows too quickly. A
small defect however could cause the system to loose a lot of
water.  Another method might use a pressure regulator that will
sit under constant pressure and work when the water is not
flowing. In other words, it will be hooked up to the outdoor
faucet and be connected to a small low pressure tube. So, the
pressure can't build up when the water is off (some models say
they only work when the water is flowing). This should probably
go down 10 PSI or lower