Question: asked about death of common carp fingerling due to green algal bloom 
Answer: first reduce organic load of pond, stop fertilization and reduce feeding rate
apply lime 5 kf per bigha and put 20 to 25 pundle of dry paddy straw and change it after every 7 days. continue for 1 month
chemical treatment: copper sulphate @ 250 gram per bigha and do not use pond water for 1 month
clean the pond bottom after every harvest using probiotic or any types of cleaner