Modern Ebb & Flow benches provide a sturdy, level, waterproof bench top surface on which the plants are grown. The benches are designed to be perfectly level, and the bench surface (typically vacuum-formed polystyrene) has drainage channels and plumbing wells to ensure complete drainage of irrigation water from the crop when the irrigation cycle is done. When the crop requires watering, the irrigation solution is pumped into the bench, and then allowed to drain, and is returned to the holding tank to be reused. The process from starting a watering cycle until the bench is at full irrigation (typically about 3/4″ of water), and then completely drained again usually takes 15 to 20 minutes. During this time capillary action within the plant root media takes up the irrigation solution, thoroughly watering the crop.