This research aims to eliminate the top sedimentation CAKE in gravity filtration for water purification in almost all water treatment plants due of blocking of large turbidity particles on top of first filter layer, it is strongly recommended to use a coarse materials that is lighter in density from sand, and can be float above the sand layer during the filtration circle back washing, our goal idea is to used crashed bricks due to its huge availability, cheep, high porosity &, less specific weight, bricks well washed and crashed mechanically then sieved to perform the required size, lab tests was made using waters supplied from city main network mixed with controlled percentage of kaolin as turbidity. Chemical are used to coagulate suspended materials before the filtration stage, chemical used include alum with some catalyst, such as poly electrolytes.