Garnet sand is used as a support layer in a multi-media filtration system. Garnet is a naturally occurring gem mineral with uniform physical, chemical, hardness, friability and micro-structure characteristics, which provide the essential properties for water and industrial chemical filtration processes. Applications for garnet sand range from small, single-media filters to technically advanced multimedia commercial and industrial systems. Garnet sand helps to remove suspended particles from chemical and/or water filtration processes.

Because of its hardness, high specific gravity and the pounds per cubic foot, garnet sand, when installed correctly, stays in its own layer holding down the layers underneath during backwash. The layers above the garnet sand are lighter in weight (per cubic foot) and therefore they lift during backwash and dislodge the "floc" cleaning of the filter media. The Garnet sand is not used to replace silica sand but rather one or two support layers of garnet sand are used beneath the silica sand. Garnet sand is so durable and heavy that the layers above will be replenished or replaced well before the garnet and filter rock layers are replaced. Therefore, time and money are saved by using garnet sand in a filtering system.