It is FILTER sand which has a very high scale of hardness, is suitable for backwashing and is produced naturally. Since the quartz sands obtained by crushing are angular, they are more successful in holding the particles in the water. Filter sands do not dissolve against pool chemicals, acid and other factors, pollute the water because of being highly silica and there is no decrease in the amount. It can used safely in drinking water, waste water treatment facilities, swimming pools, closed circuit boiler filters.