The separation of suspended solids from river water has been the subject of many investigations over the years, attempting to improve the design and economy of conventional methods. The flocculator with helically coiled tubes is a newly recommended system for improved operation in the future. Here its performance has been studied and compared with that of the jar test flocculator. The experimental data obtained have indicated that the flocculator with helically coiled tubes gives improved removal of suspended solids with a lower velocity gradient and shorter detention time compared with the conventional jar test in water treatment.