Adequate evaluation of the aquatic environment of any water body requires thorough knowledge of its many facets, not the least important of which is the relative concentration of nutrients (elements) within its various components. Previous research has been primarily concerned with determination of the roles of one or more of these elements within a single component of an aquatic environment. This chapter summarizes information on relative concentrations of calcium, magnesium, iron, manganese, copper, and zinc in filtered waters and suspended matter from three reservoirs on the Chattahoochee and Flint rivers and the comparative concentrations of these elements in filtered water, suspended matter, hydrosol, plants, and fish. 1 3