It is best to drain most of the water from the pond before applying poison so that less will be needed. In the case of quicklime, acidity in the pond soil affects the amount used. For acid soils, use the high dose rate mentioned in Table 1. A general rule to follow when poisoning puddles is to add poison until fish start to die. For example, one puddle may require a cup of quicklime, a cup of chlorine or a handful of mahua powder.
Experience can tell a farmer how much is required.
Calculations should be made for larger volumes of water. The following are example calculations for determining the amount of poison to use. Refer to Table 1 for help with these problems. A farmer needs to poison his pond. He plans to stock it with fish in 3 weeks.