The Impact of Silica Addition on Floc Volume Density in the Biofloc System for Juvenile Red Tilapia (Oreochromis niloticus)

Biofloc technology is a solution to the problem of waste management in aquaculture. Biofloc systems are beneficial because they not only reduce inorganic nitrogen waste from feed residues and fish excrement but also produce flocs. The aim of this research is to determine the effect of silica addition on floc volume density in the biofloc system for juvenile red tilapia. The research was conducted from January to March 2024 at the Center of Excellence in Science and Technology (PUI-PT) for Functional Nano Powder at Padjadjaran University. This study uses a Completely Randomized Design (CRD) experimental method with four treatments and three replications. The treatments used were (A) control, (B) 15 ppm silica, (C) 20 ppm silica, and (D) 25 ppm silica. The study used cylindrical containers with a capacity of 19 liters filled with 15 liters of water, a stocking density of 10 juvenile red tilapia per cylinder, with the juvenile measuring 3-4 cm and weighing 3-4 g. The parameters observed were floc volume density and water quality. The data on floc volume density and water quality were analyzed descriptively. The results showed that the addition of 25 ppm silica in the biofloc system was the best treatment for floc volume density. This was evidenced by the results in treatment D (25 ppm) achieving a floc volume density of 26.5 ml/L, which falls into the dense category. Therefore, the addition of silica concentration in the biofloc system can increase floc volume density.