questions: asked about death ofcommon carp fingerling  
 answers: first please perform water quality test- ph, oxygen (do), turbidity, ammonia, hydrogen gas
if the ph is found to be acidic, then apply 6 kg lime or chun per 3 kotha pond
if there is oxygen problem in pond, apply potasium permanganate @ 170 gram per 3 kotha pond
feed @ 3 % per body weight- half in the morning and another half in the evening
catla @ 400 fingerling for 3 kotha pond