In this method of hydroponics, a thin film of nutrient solution is constantly flowing across the plant roots in a tray or trough. Like aeroponics, this system utilizes very little to zero growing media for plant roots to colonize which in the event of pump failure gives very little time before roots dry out and can lead to loss of crop. The advantage of a NFT system is the high level of oxygen in the root zone and the relative simplicity of the components using for fertigation. This system is most popular for growing leafy greens and herbs at the commercial production level.