IoT-based pH Monitoring for Nutrient Absorption Efficiency in Hydroponic Plant at Pion Hidrofarm Start-UpAmanda Beatrice, Andi Pramono, Michael Hermawan Yuwono, Victor Runtuwene and Ida Bagus Ananta WijayaE3S Web of Conf., 444 (2023) 04037DOI: https://doi.org/10.1051/e3sconf/202344404037