This document describes a study evaluating the use of crushed coconut shells as a capping material in water filters. Researchers designed a filter with layers of gravel, sand, charcoal from burnt coconut shells, and a top layer of crushed coconut shells. Water samples taken throughout filtration showed reductions in pH, turbidity, total dissolved solids, biochemical oxygen demand, and chemical oxygen demand, indicating the filter purified the water. Specifically, turbidity was reduced by 85%, total dissolved solids by 83%, and chemical oxygen demand by 82.8%. The filter was found to be a low-cost and effective method for purifying water, though further treatment would be needed to make the water suitable for drinking.