Air baku yang digunakan dalam pengolahan air bersih sebagian besar berasal dari badan air seperti sungai, yang umumnya mengandung berbagai jenis polutan. seiring meningkatnya pembangunan, tingkat pencemaran sungai juga mengalami peningkatan. Sungai Mandar, yang terletak di Provinsi Sulawesi Barat, menunjukkan penurunan kualitas air berdasarkan hasil pemantauan dari Dinas Lingkungan Hidup, terutama akibat banyaknya sampah plastik dan limbah rumah tangga yang terbawa aliran sungai.Penelitian ini bertujuan untuk membangun sistem Fuzzy Logic Tsukamoto pemantauan kualitas air Sungai Mandar secara real-time menggunakan sensor turbidity, TDS, dan pH. Data sensor kemudian diolah menggunakan metode logika fuzzy Tsukamoto untuk menentukan status kelayakan air bagi kebutuhan MCK (Mandi, Cuci, Kakus). Hasil pengujian menunjukkan bahwa algoritma Fuzzy Logic Tsukamoto berhasil mengklasifikasikan kualitas air menjadi dua
kategori, yaitu "Layak" dan "Tidak Layak". Berdasarkan uji coba yang dilakukan dalam satu minggu pada empat waktu berbeda pagi, siang, dan sore hari , hasil pembacaan menunjukkan bahwa nilai pH berkisar antara 7.02 hingga 9.96, nilai TDS berada pada rentang 140 – 176 ppm, dan nilai kekeruhan berkisar 4.0 – 5.20 NTU. Ketiga parameter tersebut menunjukkan bahwa kualitas air Sungai Mandar masih dalam kondisi layak untuk digunakan, khususnya untuk keperluan MCK (Mandi, Cuci, Kakus).
Raw water used for clean water processing mostly comes from water bodies such as rivers, which generally contain various types of pollutants. Along with the increase in development activities, the level of river pollution has also risen. The Mandar River, located in West Sulawesi Province, has shown a decline in water quality based on monitoring results from the Environmental Agency, primarily due to the large amount of plastic waste and household waste carried by the river flow. This study aims to develop a real-time Mandar River water quality monitoring system using the Tsukamoto Fuzzy Logic method based on the Internet of Things (IoT). The system utilizes turbidity, TDS, and pH sensors, where the collected data is processed using the Tsukamoto Fuzzy Logic algorithm to determine water suitability status for bathing, washing, and sanitation (MCK) purposes. The experimental results indicate that the Tsukamoto Fuzzy Logic algorithm successfully classified water quality into two categories: “Suitable” and “Unsuitable.” Based on a one-week trial conducted at four different times (morning, noon, and afternoon), the readings showed that pH values ranged from 7.02 to 9.96, TDS values ranged from 140 to 176 ppm, and turbidity values ranged from 4.0 to 5.20 NTU. These parameters indicate that the Mandar River water is still in a suitable condition for use, particularly for bathing, washing, and sanitation (MCK) purposes.