Bio Floc Technology (BFT) is a new approach toward management of ponds, in most cases intensive tilapia or shrimp ponds.
Water scarcity, the demand for bio-security and economy, all leads to minimizing water exchange, even down to zero water exchange. Under these conditions, a major problem is the accumulation of ammonia and nitrite, both toxic to shrimp and fish. One way to solve this problem in low water exchange systems, is to recycle the water through a bio-filter system. Recirculating Aquaculture Systems (RAS) are known to work well, yet they have two major problems: First they are expensive in both investment and maintenance and secondly, they recycle water but do not recycle feed residues. Feed is becoming more and more expensive and its recycling is essential.
An alternative approach, the Bio Floc Technology (BFT) is based upon the activity of the microbial community within the pond. Water treatment is done within the pond, with no need for a separate water treatment component. Very dense microbial community develops when water exchange is limited. Typically, we find 10-1000 million microbial cells (107-109) in 1 cm3 of pond water. If we add carbonaceous material (molasses, starch, tapioca and others) to adjust the C/N ratio in feeds to 15-20, the microbes take up the ammonium from the water and create microbial protein. By the adjustment of the C/N ratio, the nitrogen problem can be easily and consistently solved.