Use of any of the chlorinated hydrocarbon and organo-phosphate group in ‘cleansing’ shrimp ponds is not recommended because of their long-term residual effects. In fact their use is discouraged. they should be handled and applied with extreme caution. Fish which are killed with chlorinated hydrocarbon and organo-phosphate poisons should not be eaten by people or animals.The use of synthetic substances, such as antibiotics and hormones, is no longer accepted in several countries. Millennium-20 is the best known compound (100% organic derivative) to selectively poison fish and shell animals predator without damaging the shrimp or food organisms in the pond. It is safe to use, while shrimp are in the pond. At the recommended dosage, it does not affect rotifers and copepods. It is bio-degradable and losses its toxicity after a short time, probably two or three days.Suggest dose = 5 Liter per acre of pond (depth 1m)The effectiveness of Millennium-20 Increases with increasing salinity. Best at 35ppt or above.