| dc.description.abstract | Biofloc technology application in aquaculture is limited by a number of limitations including the increasing of turbidity and total suspended solids (TSS). The aforementioned limitations were caused by the accumulation of metabolic wastes of feed and organic particles from the feces, as well as the low consumption level by the cultured organism, which is likely caused by the small size of bacterial aggregate. Therefore, the formation of bacterial aggregation is critical in the management system of biofloc cultivation (BFT). This study aims to evaluate the effect of ionic strength enhancement in stimulating bacterial aggregate in a BFT system. The objective of the first stage of the research was to evaluate the effect of several flocculants in stimulating bacterial aggregate represent by the decrease of turbidity. The flocculants used were kaolin, sodium sillicate, bentonite, and CaCl2. The result shows that CaCl2 is the best flocculant that reduced the water turbidity (20 NTU). The second stage was aimed to determine the most optimum ionic strength level of CaCl2. The levels tested were 5.10-5, 5.10-4, 5.10-3, 5.10-2, and 5.10-1. The result of this stage showed that I = 5.10-2 (1.7.10-2 M) resulted in the best turbidity decrease of 13.2 NTU. The third stage evaluated the effect of CaCl2 addition on shrimp survival and growth. White shrimp Litopenaeus vannamei with an average body weight of 0.3 g was stocked at a density of 20 shrimps/tank and cultured for 28 days. The result shows that CaCl2 addition has no effect on shrimp survival. CaCl2 addition at a dose of 0.46 g/L resulted in the best specific growth in this experiment. | en |
