Water quality is essential in aquaculture, particularly in intensive aquaculture (ponds, lakes). Aquatic animals can grow and thrive when water quality meets the standards and stability, or they will be mentally disabled or die when water is contaminated. Therefore, water’s chemical, biological, and physical indexes, such as dissolved oxygen, temperature, pH, must be monitored to help fish culturists control fish farming. This article proposes the simulation model of water quality monitoring in a pangasius pond based on cellular automata theory. The experiment results are verified using water quality data collected at Phu Thuan fish farm, Hau Giang province, Vietnam.