To measure the effect of zooplankton density on the growth and mortality of the common carp fry in fish farm ponds, four clay ponds of area 2500 m² were chosen, with each having no water for one month. One ton of organic fertilizer (buffalo waste) was added to each pond and then filled with water. After a week-long of restocking, the weight of 10.000 common carp larvae of 0.104 ± 0.002g was filled in each tank. All the artificial food like pellets were not kept for the fish during the experimental period (April 2 to May 18, 2019). For the results, the initial fish growth was high and then exhibited a significant decrease or ceased toward the end of the experiments. At the beginning of the experiment, zooplankton population was at the highest number, but the figure gradually went down, forming a linear trend, as the experiment progressed. That pointed out the likelihood of a strong relationship between the expected and actual growth rate with the total quantity of zooplankton, which is 99% with the significance level (P≤ 0.05). This hence leads to the establishment of the right weight for the larvae in order for zooplankton to serve as their natural food. In the process of zooplankton classification through the research in four basins, rotifers proved to be the leading group for being followed by the copepods.