SANDFILTRATION They guarantee crystal clear water. They work on the same principle as water purification in nature. The water from the pool enters the filtration system, where it passes through quartz sand that traps all impurities. It returns to the pool clear and sparkling. Sand filtration reduces the consumption of pool chemicals and is the "engine" for the operation of pool accessories. Our filters have powerful pumps, a coarse dirt trap, a pressure gauge and a 6-way valve for easy operation and cartridge cleaning.