Abstract: An automatic watering system for a plant growing in a growth medium, wherein the system comprises a water storage reservoir substantially filled with water and an air-tight closure that substantially seals a fill aperture. Water flows out of a reservoir drain opening through a water drain conduit and air in a water feed reservoir escapes through an air return conduit and into the water storage reservoir until a float valve seals the lower end of the air return conduit. Water thereafter flows into a growth medium through water feed apertures until the water level in a water feed reservoir drops below a water drain conduit and air is allowed to escape into the water storage reservoir therethrough. Thereafter the pressure differential between the water storage reservoir and the water feed reservoir is equalized, releasing the float valve to repeat the cycle.

Abstract: An automatic watering system for a plant growing in a growth medium, wherein the system comprises a water storage reservoir substantially filled with water and an air-tight closure that substantially seals a fill aperture. Water flows out of a reservoir drain opening through a water drain conduit and air in a water feed reservoir escapes through an air return conduit and into the water storage reservoir until a float valve seals the lower end of the air return conduit. Water thereafter flows into a growth medium through water feed apertures until the water level in a water feed reservoir drops below a water drain conduit and air is allowed to escape into the water storage reservoir therethrough. Thereafter the pressure differential between the water storage reservoir and the water feed reservoir is equalized, releasing the float valve to repeat the cycle.