8 Garnet, .335 Cf

This #8 Garnet from Water Softener Plus is a high-hardness, high-density granular filter media supplied in a 0.335 cubic foot quantity. Garnet is most often used as the lower, final polishing layer in a multi-media, also called mixed-media, down-flow filtration system, where its dense, fine grains trap the smallest particles and deliver superior water clarity.

The Science of Multi-Media Filtration

In a single-media filter such as a sand filter, backwash hydraulically classifies the bed by grain size, rinsing the smallest grains to the top. When water then flows down through the bed, those fine grains at the surface do most of the straining, quickly forming a cake that clogs and drives head loss up exponentially over time, with filtration confined to just the top few inches. The ideal arrangement is the opposite: large grains on top to capture large solids, with progressively finer grains below, ending with the smallest grains at the bottom for final polishing. Garnet makes this possible. With its high specific gravity of 4.0, it stays as the lower fine-grain layer even after repeated backwashing, and its 0.3 mm effective size can filter down into the 10 to 20 micron range. This inverse void gradation allows solids to penetrate deeper into the bed, providing increased solids storage, longer filter runs, and higher filtration rates.

• High-hardness, high-density granular filter media
• #8 grade at roughly 150 lb per cubic foot
• Ideal fine bottom layer for multi-media filters
• Specific gravity of 4.0; filters into the 10 to 20 micron range
• Excellent support bed for sand, anthracite, Corosex, Pyrolox, and similar media
• High hardness resists attrition for years of reliable service

A properly designed multi-media bed maintains its inverse gradation and keeps performing well even after long periods of backwashing, because it combines materials of different sizes and specific gravities. Garnet pairs naturally with lighter media such as filter sand (effective size around 0.5 mm) and anthracite (around 0.9 mm) or Filter-Ag to form the larger, less dense upper layers. The #8 grade also makes an excellent support bed beneath high-density oxidation media such as high-purity Corosex II or manganese dioxide media like Pyrolox. Applicable to both water and wastewater treatment, garnet lets designers build custom filter configurations that achieve higher flow rates, higher loadings, and better filtration than single-media beds can deliver, all while its high hardness minimizes attrition for long, dependable service life.