Copper sulfate is applied in inland waters as a management tool to control phytoplankton and the snails associated with the condition of schistiosome dermatitis. Application rates to control algae and snails range from 1.0 mg/l to 25.0 mg/l of copper sulfate, respectively. Previous studies have focused on a variety of aspects of this practice, however, few have determined the effects of copper sulfate treatments on benthic algae. Therefore, a short-term laboratory experiment was executed. Algal communities were established in laboratory microcosms using sediment and water collected from Muskegon Lake, Michigan. Microcosms were assigned to one of four treatments: control 0, 1.0 mg/l, 10.0 mg/l, or 25 mg/l of copper sulfate. After 48-hours, chlorophyll a, total dissolved copper, cell density, and community structure were determined. Chlorophyll a declined significantly due to copper, however, algal densities did not. The differences in measured responses may be due to sediment adsorption or duration of the experiment.