Gravel 3.15 – 5.6 mm

Sand, or silica, has long been recognized as one of the most ancient and versatile natural filtration media available. Its various forms, such as sand, silex, and gravel, have been extensively utilized for water treatment applications across different settings. From large-scale municipal water treatment facilities employing open gravity filters to swimming pool filtration systems and pressurized filters for groundwater treatment, sand continues to be a preferred choice.

While sand has a rich history of use in water filtration, newer granular filtration media have emerged, offering enhanced benefits such as increased flow rates, superior filtrate quality, reduced weight, and more. Despite these advancements, sand’s ubiquity in nature and widespread availability make it a reliable option for a range of filtration needs.

Naturally occurring across the globe, sand is sourced, washed, and sieved to meet specific requirements. Different suppliers offer variations in sand grades, each tailored to meet distinct filtration needs. Primarily utilized for the removal of suspended solids, sand also proves effective in filtering oxidized iron or manganese from water sources.

Pressurized sand filters are a common configuration in many filtration systems, typically comprising multiple layers of sand. The filter bed is structured with finer sand at the top, transitioning to coarser gravel as a support layer at the bottom. Intermediate layers of varying particle sizes are often incorporated between the sand layers to optimize filtration efficiency.

The stratified arrangement of sand and gravel within a pressurized filter promotes efficient filtration by capturing impurities and promoting the passage of purified water. This layered design allows for effective removal of contaminants while maintaining a steady flow rate, making it an ideal choice for diverse water treatment applications.

When considering the selection of filtration media, the versatility and reliability of sand make it a timeless choice for both traditional and modern filtration systems. Whether used in large-scale municipal facilities or compact residential setups, sand’s natural composition and filtration properties continue to play a crucial role in ensuring clean and safe water for various purposes.

Manufacturers description:

Sand (silica) in its different forms (sand, silex, gravel) is the oldest natural available granular filtration media. Even today, the use of sand remains popular for the treatment of municipal water in very big open gravity filters, in swimming pool filters and in pressurized filters for the treatment of ground water.

In a lot of groundwater applications the use of sand has been replaced with other granular filtration offering more benefits (faster flow rate, better quality of filtrate, lower in weight, etc.)

Sand is present in nature all over the world, washed and sieved. It exists in different grades that vary from one supplier to another. It is used for the removal of suspended solids, but can also be used to filter of oxidized iron or manganese.

A pressurized sand filter always contains different layers of sand, going from relatively fine sand on top to coarse gravel as a support layer. In between the use of 2 more particle sizes is common.