questions: asking about blue colour water in fish pond 
 answers: suggestion
remove green algal mate by using net
apply lime  7 kg per bigha
after 7 days apply cow dung @ 200 kg pere bigha and monthly dose @ 130 kg per bigha
 
after 5 days:
apply urea @ 3.7 kg per bigha
apply ssp @ 3 kg per bigha