Certain physico-chemical characteristics, such as temperature, pH, dissolved oxygen, free carbon dioxide, carbonate/bicarbonate alkalinity, chloride, silicate, phosphate phosphorus, and nitrate-nitrogen of surface and 1.5 m deep water showed diel variation with a varied trend. Plankton dominated the surface water during the day. Green and blue-green algae dominated at midday. Maximum density of zooplankton (584 indiv. dm-3) was recorded at 6 h followed by 10 h and 14 h.