Effect of different C/N ratio, carbon sources, and aeration flow rates on ammonia fluctuations during start-up period of biofloc-based system

Biofloc is a new emergence technology in aquaculture industry that relies on the carbon and nitrogen ratio to remove the toxic nitrogenous waste from aquaculture water. This technology requires start-up period to achieve well-functioning system in maintaining the good water quality for sustainable aquaculture system. During this stage, ammonia fluctuation typically occurs due to bacteria development. This study aimed to evaluate the effect of different carbon to nitrogen (C/N) ratios, carbon sources, and aeration flow rates on the ammonia fluctuations during start-up period of biofloc formation using bioflocculant-producing bacteria, Bacillus infantis as inoculum. This experimental study was conducted in 25 L synthetic aquaculture water that initially contained ± 5 mg/L to study the ammonia trends in varied C/N ratio (5, 10, 15, 20), carbon sources (molasses, rice bran, glucose, and sucrose), and flow rates (