Results
3.1. Biofloc development and water quality
The biofloc development in terms of BFV and TSS over time is shown in Fig. 1. Both BFV and TSS levels increased gradually throughout the ex- perimental period and their changing tendency over time was basically
consistent. The treatments with higher dietary protein level had slightly higher BFV and TSS levels, and at the end of the experiment both of them were below 26 mL L− 1 and 430 mg L− 1, respectively.
The results of the main water quality parameters monitored are shown in Table 2. Except for the occasional regulation of pH, all water quality parameters remained within the recommended levels for shrimp culture throughout the experimental period.