Question: asking about death of fish in morning 
Answer: suggested to apply lime @ 10 kg per bigha mix the ammount with suitable amount of water and keep for 1 night and apply on the pond water on next day
 apply oxymore @ 20 tablet per bigha apply on the whole area of pond water
if oxymore tablet is not available then potassium permanganate can be applied @ 300 gram per bigha mixing with suitable amount of water to get dissolved