The Effect of the Use of a Settling Chamber in the Cultivation of Penaeus vannamei and Salicornia neei in Aquaponics with Bioflocs.

Abstract

This study aimed to evaluate the effect of the continuous use of the settling chamber for solids removal in the cultivation of the marine shrimp Penaeus vannamei and the halophyte Salicornia neei in an aquaponic system with bioflocs. Two treatments were tested: with settling and without settling. Each experimental unit consisted of an 800 L tank for shrimp rearing (stocking density of 375 shrimp m^-3) and a hydroponic bench of 0.33 m² for 28 seedlings (84 plants m^-2). In the treatment without settling, water was continuously pumped to the hydroponic bench. In the treatment with settling, the water was first pumped to the chamber, and the overflow was then distributed across each irrigation channel, returning to the tank by gravity. To maintain the concentration of suspended solids in the shrimp culture, solids that accumulated in the settling chamber were pumped back into the tank every 30 min. During the 54-day trial, the reduction in suspended solids in the treatment with settling led to an increase in TAN and NO₂ levels, while the concentration of NO₃ remained stable. Although water quality parameters were more stable in the treatment without settling, no significant differences were observed between the treatments regarding plant and shrimp production indices. These results demonstrate the feasibility of cultivating P. vannamei and S. neei in a biofloc-based aquaponic system without the continuous use of a settling chamber during the pre-grow phase (until 10 g), offering a potential method for simplifying aquaponic system design.