Reusing water in a biofloc culture system favors the productive performance of the Nile tilapia (Oreochromis niloticus) without affecting the health status

Freshwater scarcity is a global problem and tends to be more severe. Five treatments reusing different percentages of water from a commercial BFT tilapia farm were evaluated: R0 (0%), R25 (25%), R50 (50%), R75 (75%) and R100 (100%). The water variables, fish and biofloc proximate compositions, as well as productive fish response and blood parameters, were determined. During the cultivation period, dissolved oxygen, temperature, and pH were similar between treatments, while alkalinity, total suspended solids, chlorophyll a, total ammonia nitrogen, and nitrite, showed significant differences (P < 0.05). The best productive response was obtained in the treatments with the highest water reuse (P < 0.05). The protein content in biofloc (24.92-26.30%) and tilapia (63.21-63.80%) was similar between treatments. No physiological implications by reusing water were detected; hematocrit ranged from 24.67 to 28.67%, erythrocytes 2.01-2.31 x 10(6) cell/mm(3), plasmatic glucose 73.45-79.93 mg/dL, and plasmatic proteins 3.20-3.58 g/dL. The results suggest that it is possible to reuse biofloc water, positively affecting water quality and productive response, and causing no adverse effect on the fish's health.

Automated summary

Freshwater scarcity is a global problem that is becoming more severe. This study evaluated the effects of reusing different percentages of water from a commercial BFT tilapia farm. The results showed that higher rates of water reuse had a positive impact on water quality and productive response, with no adverse effects on the health of the fish.