Certified filter sand with a grain size of 0.7–1.25 mm is a high-quality sharp-edged quartz sand of German manufacture intended for sand filter tanks. Thanks to certification according to ČSN EN 12904 and EN 19643, it meets the strict requirements for filtration of both drinking and pool water, and is tested according to DIN EN 4924.
The sharp-edged grain shape ensures significantly higher filtration efficiency compared to round sands, as it creates a denser filter layer that captures even fine impurities. The sand is thoroughly washed, clean, free of dust, clay and organic admixtures, which guarantees clean water immediately after the first filling of the tank without lengthy rinsing.
The sand is supplied in a sturdy plastic bag of 25 kg, which protects the contents from contamination during storage and handling. For a standard domestic filter tank with a diameter of 500 mm, approximately 50–75 kg of filter sand is recommended. Sharp-edged sand with this grain size is a globally recognised standard for pool sand filters.
