Fuzzy Logic-Based Automated pH and Temperature Control System for Biofilter in Smart Aquaponics
Authors: Amir A. Bracino, Ronnie S. Concepcion II, Danielle Grace D. Evangelista, Ryan Rhay P. Vicerra, Elmer P. Dadios
Abstract
Aquaponics is a modern agricultural approach that relies heavily on recirculating water between aquaculture and hydroponic units, thus a specialized set of water chemistry is needed to sustain a healthy and functioning aquaponics system. The addition of a biofiltration system helps in converting ammonia, a toxic byproduct of fish metabolism, to nitrates which is the nitrogen form that can easily be utilized by plants. Naturally present nitrifying bacteria need an optimum pH and temperature to maximize the conversion of ammonium to nitrites and nitrites to nitrates. Thus, monitoring and controlling the pH and temperature is needed to maintain a functional aquaponics system. To address this problem, a fuzzy logic-based system is created to control the solenoid valves that will supply additional acid or base and switches for the Peltier cooler and heater for correcting the temperature in the biofilter. Using the Mamdani approach in the fuzzy inference engine, the duration of the opening for the solenoid valves, cooler, and heater were suggested.