<![CDATA[The Nutrient Film Technique (NFT) hydroponic system requires stable nutrient solution management, particularly pH and nutrient concentration parameters that affect plant nutrient absorption. Based on observations conducted at the Mega Regency greenhouse, pH and nutrient monitoring are still performed manually, causing changes in nutrient conditions to not be monitored continuously in real-time. This study aims to design and implement an Internet of Things (IoT)-based monitoring and control system for nutrient solutions in NFT hydroponics. The development method used is Rapid Application Development (RAD). The system was developed using an ESP32 microcontroller integrated with pH, TDS, DS18B20 temperature, and ultrasonic sensors, as well as actuators in the form of pH up, pH down, and AB Mix nutrient pumps. Sensor data were processed using the Exponential Moving Average (EMA) method to reduce reading noise, while the control process applied the hysteresis method. Monitoring data were sent to the ThingsBoard platform and displayed through a Cloud-based dashboard. The results showed that the system was capable of continuously monitoring pH, nutrient concentration, temperature, and water level, with sensor accuracy reaching 95.84% for pH, 98.66% for TDS, and 97.14% for ultrasonic sensors. The EMA method effectively reduced sensor reading fluctuations by up to 0.74 pH units, while the hysteresis method maintained parameters within the specified range through automatic pump activation. During integration, electrochemical interference was found between pH and TDS sensor probes in the same reservoir. Various solutions were attempted progressively, from voltage stabilization using capacitors, switching power mechanism via transistors, to probe relocation to different pipe flow points as the more effective final solution. The developed system supports hydroponic management more effectively and automatically]]>
