The use of different aerators on Litopenaeus vannamei biofloc culture system: effects on water quality, shrimp growth and biofloc composition

This study evaluated the effects of different aeration types on water quality, shrimp growth and biofloc composition in a Litopenaeus vannamei culture. The study was conducted with three treatments: (1) PR-propeller aspirator pump aerator; (2) VP-vertical pump aerator; and (3) BL-diffused air blower. The study was performed in a greenhouse with nine 35,000-L rectangular tanks. Water quality parameters (temperature, salinity, dissolved oxygen, pH, ammonia, nitrite, nitrate, settleable and suspended solids) were measured along the 33 experimental days. Moreover, samples were collected to quantify the microorganisms present in the tanks. At the end of the study, samples of the biofloc of each tank were collected to proximal analysis. Throughout the experiment, the temperature, pH, salinity and alkalinity were maintained within the recommended levels for L. vannamei. The propeller treatment showed a concentration of total ammonia above the recommended levels and lower densities of ciliates and flagellates, most likely because of inadequate biofloc formation in this treatment. The final weight was higher in the blower and propeller treatments. However, survival was lower in the propeller treatment compared to the other treatments. The results of this study suggest that diffused air systems (air blower) improve the formation of biofloc and growth performance of L. vannamei.