<![CDATA[The rapid reduction of agricultural land in urban areas necessitates the development of efficient and scalable farming systems. This study aims to develop an IoT-based monitoring and control system for hydroponic pakcoy cultivation using the Nutrient Film Technique (NFT), with a focus on improving environmental stability and supporting sustainable urban farming. The proposed system integrates multiple sensors, including pH, Total Dissolved Solids (TDS), water temperature, air temperature, and humidity sensors, with Arduino Uno and ESP32 microcontrollers. The system enables real-time data acquisition, cloud-based monitoring via Firebase, and automatic control of nutrient conditions using threshold-based mechanisms. The accuracy of the system was evaluated using the Mean Absolute Percentage Error (MAPE) method by comparing sensor readings with standard instruments. The results show that all sensors achieved excellent accuracy, with MAPE values of 1.36% for water temperature, 2.15% for air temperature, 1.38% for humidity, 5.52% for pH, and 7.82% for TDS. Furthermore, the system successfully maintained key hydroponic parameters within optimal ranges (pH 5.5–6.5 and TDS 1050–1400 ppm), which are essential for nutrient availability and plant growth. This stability reduces environmental fluctuations and minimizes plant stress, thereby supporting more consistent growth conditions for pakcoy cultivation. In addition, the implementation of real-time monitoring and automated control reduces manual intervention and improves operational efficiency in urban hydroponic systems. These findings demonstrate that the proposed IoT-based system not only provides accurate environmental monitoring but also contributes to improving the reliability and efficiency of hydroponic farming, making it a promising solution for sustainable urban agriculture.]]>
