Iraqi Journal of Veterinary Sciences

Abstract

Abstract. Many Indonesian catfish farmers apply the aquaponics system to overcome the problem of limited cultivation land. However, the use of high-stock solid method on aquaponics system causes a decrease in water quality due to the accumulation of fish feces and food scraps that are not consumed by fish and are left to pile up and turn into ammonia. Ammonia in water is toxic and dangerous for fish health. This study aimed to determine the effect of Nitrobacter bacteria on specific growth rate (SGR), survival rate (SR), and feed convertion ratio (FCR) of African catfish (Clarias sp.) in aquaponics systems. The sample used was African catfish with a size of 5-7 cm as many as 720 individuals. The research method used was experimental design in the form of Completely Randomized Design (CRD). This study used 5 types of treatments with 4 repetitions. The control group were treated without Nitrobacter administration and 4 intervention groups were given Nitrobacter 1 ml with a density of 1x108 CFU ml-1. The main parameters observed were SGR, SR and FCR. Whereas, the supporting parameters were water spinach (Ipomoea aquatica) plant growth and water quality conditions in aquaponics systems. The administration of Nitrobacter in aquaponics systems gave a significant effect on the SGR, SR, and FCR of catfish. The administration of Nitrobacter in an aquaponics system can give maximum effect if there are 45 fish stocking densities and 1 ml Nitrobacter with a concentration of 1x108 CFU ml-1.