Question: asking death of fish and turbidity
Answer: lime @ 10 kg per bigha mix lime with suitable amount of water and keep it for one night and apply on the pond water on the nextr day 
on next day apply oxymore 20 tablet per bigha apply this tablet directly into the pond 
if oxymore tablet is not available then you can use potassium per manganate 300 gram for 1 bigha mix this potassium permanganate with suitable amount of water and stir it with a stick in order to get dissolve  and broadcast on the pond surafce 
kvk 9435092550 gunjan gogoi