Effect of Probiotics in Recirculating Aquaculture System (RAS) on the Concentration of Ammonia, Nitrite, and Nitrate in the Aquaculture of Catfish ( Clarias sp.)

The purpose of this research is to determine the effect of probiotic administration on ammonia, nitrite, and nitrate levels in catfish cultivation (Clarias sp.) with the RAS system. The research was conducted in February - March at the Anatomy Laboratory and chemical laboratory of the Faculty of Fisheries and Marine Airlangga University. This study was conducted experimentally using the RAL method consisting of 5 treatments four replays, namely control treatment (P0), probiotic dose 0.5 mL/L (P1), probiotic dose 1 mL/L (P2), probiotic dose 1.5 mL/L (P3), and probiotic dose 2 mL/L (P4). Data analysis is processed using ANOVA and DMRT. The result of this study was the administration of probiotics with the bacterium Nitrosomonas sp. And Nitrobacter sp. with different doses has an effect (p<0.05) on the concentration of ammonia, nitrite, and nitrates.