Automated Nutrient Sensing and Recycling

Abstract. The goal of this project was to develop a low-cost automated system to recycle used nutrient solution in a closed loop hydroponic growth system. The system works by maintaining stable nutrient concentrations in the hydroponic solution and controlling them to set point levels. This would be achieved by using ion selective electrodes (ISE), electrical conductivity (EC) and pH sensors.  During operation, the system would monitor real-time nutrient concentrations in the solution and attempt to maintain pre-set nutrient ratios or concentrations. The main goal of this system is to improve the nutrient and water use efficiency without diminishing yield quantity and plant quality. The secondary goal is to allow researchers to have a better understanding of root system nutrient uptake across plant cultivars and stages of growth. The final goal is to reduce water quality pollution from disposal of used nutrient solution by hydroponic producers.