Abstract: Chemicals are added to a fluid such as sewage to flocculate and precipitate solids therefrom which are deflected downwardly and sink by gravity to the base of an elongated chamber so that the substantially clarified fluid flows over a weir at one end of the chamber with the flocculated and precipitated material forming a sludge in the base thereof whereafter it may be removed either through a fluid lock device or pressurizing the system to stratify the flow and provide still areas for the sludge to settle through the fluid and be removed as required.