Process involving repeatedly applying some of the liquid composition to the granular filter media to remove water from the liquid composition by passing through the granular filter media with the particulate solids collecting on top surface of granular filter media. Water is first allowed to fill from below to just above the top layer of the filter media. A non-porous liner is located on the inner, bottom surface of the container. A drain pipe, having small openings, is located on top of the liner in the valley. A porous layer of large filter media, with the drain pipe therein, is located in the bottom of the container. A grid having open passageways, with fine filter media therein, is located on top thereof. A layer of fine filtrate sand is located on top of the grid.