Multi-species biofloc bacteria and application test on snakehead fish (Channa striata bloch, 1793) juvenile

Multi-species bacteria in biofloc fish farming systems are used as an effective way to decompose nitrogen waste. Snakehead (Channa striata Bloch, 1793) fish farmers require biofloc bacteria to improve growth performance. This research aims to easily evaluate the multi-species biofloc bacteria consisting of Lysinibacillus fusiformis, Bacillus sp., and Bacillus subtilis and their application on snakehead fish. The bacterial density tests on molasses mounting media in indoor and outdoor hatcheries were done. The research location was at the multi-species hatchery, aquaculture environment, and toxicology research installation. The experiment fish used was snakehead fish with a length ranging from 12-15 cm and a stocking density of 15 fish per container. The fish parameters measured were total length (cm) and average body weight (g). Water quality parameters: temperature, pH, DO, nitrite, nitrate, and ammonia. The parameter measurement of bacteria was the growth number, and floc bacteria was measured on volume. An application test in a laboratory scale was done with probiotic stocking doses: A (2 mL L-1 probiotic), B (4 mL L-1 probiotic), C (6 mL L-1 probiotic), and D (control, 0 mL L-1 probiotic. The results show the best dose in applying snakehead fish culture with biofloc was 4 mL L-1.