The disaster that hit Palu City recently caused changes in the quality of water consumed by the community. To find out whether it is feasible or not, a method is needed to detect a water quality system that is easy to apply at an economical price so that people can know for sure the quality of the water they use for their daily needs. Therefore, a tool is designed to determine the quality of water, which samples are taken around the coast of Tondo by using the Fuzzy Logic method. This design was built using the Arduino module by combining four sensors, namely a pH sensor, a TDS sensor, a Turbidity sensor, and a temperature sensor. Water quality in this study was divided into three groups, namely drinking water (UM), water for washing (UC), and water not suitable for use (TL). While the water quality benchmarks are known from the incorporation of existing sensor readings, so that the value of water quality measured in the study is in the unsuitable category with a fuzzy value of 100 in sample 1, and to use washing with a fuzzy value of 45.68 in sample 2, and 26.4 in sample 3.