Bio-flock is an innovative and cost-effective technology in which toxic materials to the fish and shellfish such as Nitrate, Nitrite, Ammonia can be converted to useful product, ie., proteinaceous feed. This technology is  used in aquaculture system with limited or zero water exchange under high stocking density, strong aeration and biota formed by bio-floc.

Biofloc system is a wastewater treatment which has gained vital importance as an approach in aquaculture. High stocking density and rearing of aquatic animals requires wastewater treatment.principle of this technique is the generation of nitrogen cycle by maintaining higher C: N ratio through stimulating heterotrophic microbial growth, which assimilates the nitrogenous waste that can be exploited by the cultured spices as a feed. The biofloc technology is not only effective in treating the waste but also grants nutrition to the aquatic animal.

Higher C : N is maintained through the addition of carbohydrate source (molasses) and the water quality is improved through the production of high quality single cell microbial protein. In such condition, dense microorganisms develop and function both as bioreactor controlling water quality and protein food source. Immobilization of toxic nitrogen species occurs more rapidly in bioflocs because the growth rate and microbial production per unit substrate of heterotrophs are ten-times greater than that of the autotrophic nitrifying bacteria. This technology is based on the principle of flocculation within the system.

Bio-Flock system was invented in Indonesia .From there, it spreaded all over the world. Last Week ,I visited farm of Mr. Rajan Budhathoki, who has installed two bio-flock plant in his farm in Itahari. This is very good initiation to promote Food Security.