To produce 1 kg live weight fish one needs 1–3 kg dry
weight feed (assuming a food conversion ratio about 1–3)
.About 36%of the feed is excreted as
a formof organic waste .Around 75%
of the feed N and P are unutilized and remain as waste in
the water . An intensive aquaculture system, which contains
3 ton tilapia, can be compared on a biomass basis to a
human community with 50 inhabitants . This intensive aquaculture system can also be
compared on grounds ofwaste generation to a community
of around 240 inhabitants .