US Patent 7867396 Water treatment apparatus, method and system

A modular water treatment apparatus is disclosed having a plurality of cells each respectively arranged in use for housing a treatment bed and a plurality of spacers located between respective adjacent cells. In use the spacers are for providing an air gap between the cells. The cells and spacers are stackable to provide a multiple stage treatment apparatus in which water to be treated percolates through the respective treatment beds located in the cells.