The minimum impeller speeds for complete drawdown and concentration distributions of floating solids in an agitated vessel are measured for impellers used commonly in process industries, namely disc turbine impellers and pitched paddle impellers. A correlation for the minimum impeller speed is developed for disc turbine impellers and pitched paddle impellers rotating to create downward flow. The relatively uniform concentration distributions are obtained in spite of different impeller geometries compared to those reported for solids heavier than the liquid media.