© 2019 Elsevier B.V. Chirostoma estor estor, commonly known as whitefish, is an important species that lives in some Mexican lakes and is endangered due to overexploitation. This work proposes a new computational model for water quality assessment in freshwater intensive culture tanks using fuzzy logic, and an Analytical Hierarchy Process (AHP). The most critical parameters for whitefish culture, namely dissolved oxygen, pH, temperature, total ammonia, and non-ionized ammonia, were measured. Using measurements from real cultured tanks, different situations were studied to define importance parameter weights. As a result, an index concerning good or bad water quality conditions was obtained. Chirostoma farms were assessed using the proposed index to detect potential undesirable situations, improving water management for a constant growth, reproduction and survival of this important fish.