My Aquamatic Systems monitor the soil moisture in up to 4 locations and control the watering of the soil as needed. Sensors placed in the soil feed information to a controller operated by digital logic devices and determine amount of water to release.
Systems will operate with 24vac from household timers, a solar cell/battery or 110v DC Converters.
Systems are presently in use with a Hydroponics Grow Bed maintaining the cycling of water between 2 tanks as well.
Material parts for these systems vary as to power source, but range from $10 to
$50 making them very affordable for the average person.