326 Sistem kontrol nutrisi floating.... (Kurniawan dan Lestari) SISTEM KONTROL NUTRISI FLOATING HYDROPONIC SYSTEM KANGKUNG (Ipomea reptans) MENGGUNAKAN INTERNET OF THINGS BERBASIS TELEGRAM CONTROL SYSTEM OF NUTRIENT IN FLOATING HYDROPONIC SYSTEM FOR WATER SPINACH (Ipomea reptans) USING TELEGRAM-BASED IoT Anri Kurniawan 1 , Hanis Adila Lestari 1 1 Program Studi Teknik Pertanian dan Biosistem, Fakultas Sains dan Teknologi, Universitas Nahdlatul Ulama Purwokerto.  Komunikasi Penulis, email : a.kurniawan@unupurwokerto.ac.id DOI:http://dx.doi.org/10.23960/jtep-l.v9.i4.326-335 ABSTRACT Nutrient water in the reservoir of floating hydroponic system serves to meet the nutritional needs of hydroponic plants. Continuous circulation for 24 hours causes the water level to decrease due to the evaporation process in plants, resulting in reduced reservoir water every day. The research was conducted by designing a monitoring tool for water level and nutrient of water spinach (Ipomea reptans) on floating hydroponics through the telegram application. Ultrasonic Sensor HC-SR04 as water level reader and sensor TDS DFrobot as a nutrient reader and 2 channel relay as an automatic on-off pump for water and nutrients. The telegram API bot through the botfather is synchronized with nodeMCU-ESP32 so that it can be controlled via the internet of things (IoT) system. Telegram can receive and request information on water levels, TDS, pump status, start and stop water pumps, and nutrients. The water pump is “on” at a height of less than 15 cm and the pump is “off” at a height of above 20 cm, while for the nutrient pump it is “on” at a TDS value of less than 500ppm and “off” at a TDS value above 1000ppm. In ultrasonic sensor testing, an error of 0% was obtained, while in TDS sensor testing, an error of 0-04% and 0-05% was obtained. The hydroponic raft of floating water spinach at the age of 30 HST reached an average plant height of 52.63 cm and a total weight of 31.25 grams. Keywords: floating, hydroponic, IoT, telegram, water spinach ABSTRAK Air nutrisi pada reservoir hidroponik rakit apung berfungsi untuk memenuhi kebutuhan nutrisi tanaman hidroponik. Sirkulasi yang terus menerus selama 24 jam menyebabkan ketinggian air berkurang akibat proses evaporasi pada tanaman, mengakibatkan air reservoir berkurang tiap harinya. Penelitian dilakukan dengan merancang alat monitoring ketinggian air dan nutrisi tanaman kangkung (Ipomea reptans) pada hidroponik rakit apung melalui aplikasi telegram. Sensor Ultrasonik HC-SR04 sebagai pembaca level air dan Sensor TDS DFRobot sebagai pembaca pekatan nutrisi serta relay 2 channel sebagai on-off otomatis pompa air dan nutrisi. Bot telegram API melalui botfather disinkronkan dengan nodeMCU-ESP32 sehingga dapat dikontrol melalui sistem internet of things (IoT). Telegram dapat menerima dan meminta informasi tinggi air, TDS, status pompa, menghidupkan dan mematikan pompa air serta nutrisi. Pompa air “on” pada ketinggian kurang dari 15 cm dan pompa “off” pada ketinggian di atas 20 cm, sedangkan untuk pompa nutrisi “on” pada nilai TDS kurang dari 500 ppm dan “off” pada nilai TDS di atas 1000 ppm. Pada pengujian sensor ultrasonik didapatkan error 0%, sedangkan pada pengujian sensor TDS didapat error 0-0,4 % dan 0-0,5%. Tanaman kangkung hidroponik rakit apung pada umur 30 HST mencapai rata-rata tinggi tanaman 52,63 cm dan bobot total basar sebesar 31,25 gram. Kata Kunci: floating, hidroponik, IoT, kangkung, telegram Naskah ini diterima pada 16 September 2020; revisi pada 27 November 2020; disetujui untuk dipublikasikan pada 16 Desember 2020