Land of course, but any land would not do. Site selection is most important requirement in aquaculture. For site selection, Soil Quality, Water Quality & Availability, Topography of the Land, Drainage Channel / Sem Nali and the location are very important. The soil must have 25 - 30% clay content for building dykes, water retention and good production. There must be ample water of good quality. Lifting water to fill in large ponds is very costly and area that can be gravity filled and or drained are preferred.