RESUMEN
An investigation was carried out in Ramankere tank near Honalli of Davangere on physico-chemical characteristics and Planktonic composition during January to December 2011. The results of physico-chemical parameters were compared with the standard values prescribed by the Bureau of India Standards (BIS) and World Health Organization (WHO). The study revealed that, tank water is polluted as it possesses high BOD, CO2, phosphate and nitrogen. A total of 36 species belonging to 27genera of phytoplanktons were recorded, of which Bacillariophyceae and chlorophyceae were dominant. Eight zooplanktons and six macrophytes were also recorded. In the light of standard of water quality recommended by WHO, the tank water should not be used by human beings especially for drinking and cooking.