In the present investigation impact of copper as a microfertilizer of water for better production of zooplankton has been studied. Varying Cu concentrations (as CuSO 4.5H 2O), Viz. 0.02, 0.04. 0.06 and 0.08 mg/l were tried in combination with farm yard manure (FYM - 2g/l) to fertilize the water for 49 days. FYM (2g/1) was used independently as control. The average zooplankton population were observed significantly high (P ± 0.01) in all Cu fertilized water as compared to control. Among various levels of Cu fertilized water, 0.08 mg/l showed highest population of zooplankton (1290 nos/l) followed by 0.06 (1190 nos/l), 0.04 (930 nos/l) and 0.02 mg/l (850 nos/l). The lowest zooplankton population (690 nos/l) was evident in control, i.e. FYM fertilized water. In Cu fertilized water cladocerans showed significant increase in population followed by copepods, nauplii and rotifers. Physico-chemical characteristics indicate that traces of Cu along with FYM did not influenced pH, dissolved oxygen, carbon dioxide and alkalinity of the culture water. However, orthrophosphate and nitrate-nitrogen concentrations were observed higher in water treated with Cu.