The Smart-valve controls the water level in a module (or your own tray) to give plants a wet-dry cycle. Unlike a conventional float valve, a Smart-valve allows total reduction of the fluid level before it refills. When connected to a water supply (which can be from either pressure reduced mains, or gravity tank) the valve opens to allow water to enter the bottom of the growing container to a set depth (approx 35mm). The valve then closes to stop further water to enter the container until all the original supply has been completely used. This absorption is achieved by capillary action that naturally occurs in the growing medium. Once the water has been absorbed to the extent that the film of water under the valve has gone, the valve re-opens and another supply of water enters the growing container - wet-dry cycles dictated by the plant's own rate of consumption
