Silica sand is a high-quality filter media commonly used in swimming pool filtration systems. This type of sand is carefully sized and graded to ensure optimal performance in removing debris, dirt, and other impurities from pool water.Specifically, it means that the sand has a particle size ranging from 0.4mm to 0.8mm. This size range is ideal for swimming pool filters, as it allows for efficient filtration without excessive pressure drop or clogging.