If possible, ponds should be lined. In soil ponds without lining, the intensive water flow can erode pond banks and add significant amounts of fine soil particles to the bottom sludge. In addition, the large amounts of organic residues sinking to the pond bottom will mix with soft mud and create a deep sludge layer that is hard to control. All this will generate anaerobic condition in the pond bottom failing fish (or shrimp) production. Lining can be made using plastic sheets (HDPE), soil – cement mixture or compacted Laterites.