Sand is the most cost effective media. The grade of sand is tightly controlled so only highest quality, triple washed water treatment grade sand is used. The water passes through the sand and any particulates get trapped by the sand. Particles above 40 micron are typically trapped.
Filter Ag has a high surface area and complex flow path for a more efficient removal of suspended matter. Typically particles down to 20 micron can be trapped. Filter Ag is slightly more expensive than sand and should be soaked for 24 hours before use. A 50:50 mix of sand/Filter Ag forms an excellent value media mix.
How does it work?
Water flows into the valve at the top, down through the media and then up through the riser tube in the middle of the vessel. As the water travels through the media the sediment is trapped so only clean clear water flows out to service. There are timer options that can be set to automatically self clean (backwash) and wash away any of the accumulated sediment.