The AQUAvalve is supplied with all the AutoPot Watering Systems. Once connected to the water supply the AQUAvalve will control the flow of water to the plants, by simple gravity pressure from a tank or water butt, no pumps, mains water pressure, electricity or timers are required. Once connected to a tank the AQUAvalve will open and allow water to fill the tray to a preset level of 20mm. The AQUAvalve will not refill the tray until all the water has been used allowing the plant to go through a wet & dry cycle. Once all the water has been used by the plants the AQUAvalve will re-open and refill the tray. The AQUAvalve is a simple but very effective watering device and needs to be treated with care. Keep the AQUAvalve and the tray it sits in clean, free of obstructions, soil particles and it will help you water & feed your plants for many years. The AQUAvalve is guaranteed for 12 months.