Abstract

Water quality and the culture performance of juvenile rainbow trout (On-corhynchus mykiss) were evaluated between 2014 and 2017 in a recirculating aquaculturesystem (RAS) in the Chilean Altiplano. Key parameters such as temperature, total ammonianitrogen (TAN), nitrates, and dissolved oxygen were monitored, with values ranging from7 to 21◦C, <0.1 to 0.63 mg/L, 2.0 to 135 mg/L, and 1.8 to 7.5 mg/L, respectively. Additionalparameters—including alkalinity, arsenic, chlorine, true color, conductivity, hardness, phos-phorus, pH, potassium, suspended solids, and salinity—were also assessed, comparingdifferent points within the system (head tank, culture tanks, and settling tanks). The resultsshowed that water quality remained within acceptable ranges for aquaculture, althoughfluctuations in pH and low alkalinity levels caused stress in the fish. Despite these chal-lenges, the specific growth rate (SGR) was 1.49, the feed conversion ratio (FCR) was 1.52,and weight gain reached 298.7%, with a survival rate of 96.2%. This study demonstrates thataquaculture in the Altiplano is feasible and can contribute to the sustainable developmentof aquaculture in the region. Furthermore, it highlights the importance of comprehensivewater quality monitoring to optimize RAS performance in challenging environments.