Garnet Sand

Home / Filter Media / Garnet Sand

Photo of Garnet sand. It is used in a multi-rock multi-media water filtration system.Garnet sand is used as a filter media as a support layer in a multi-media filtration system. Garnet sand has various uses as an industrial mineral. Garnet is used to filter out some contaminant particles in water filtration systems. Garnet’s high hardness and high specific gravity help reduce bed expansion and particle abrasion during backflushing in water filtration systems. Garnet is a naturally occurring gem mineral with uniform physical, chemical, hardness, can be reduced to smaller pieces with little effort, especially by rubbing, and has 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.

Garnet is used in waterjet cutting, abrasive blasting, water filtration, abrasive powders and has various other uses. Garnet is a relatively hard mineral that allows it to be used as an effective abrasive in many types of manufacturing. When it is crushed it brakes into angular pieces where the sharp edges are good for cutting and sanding. Small granules of garnet are used on sandpaper.

The George L. Throop Company supplies garnet sand in many different sizes that is AWWA B100 and NSF 61 certified.

Garnet Sand Physical Characteristics:

  • High specific gravity: 3.8 – 4.2
  • Weight per cubic foot: 120 – 151 lbs
  • MOH hardness scale: 7.6 – 8.0
  • Acid solubility: <1%

Sizes of garnet sand for water filtration:

  • ES 1.4 x 1.55
  • ES 1.4 x 1.7
  • ES .35 x .45
  • ES .25 x .30
  • ES .21 x .28
  • ES .15 x .25

Cleanliness: Low dust

Durability: 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.

Garnet sand from the George L. Throop Company is available in the following packaging:

  • 50 lb sacks
  • 3,000 to 4,000 lb Supersack bags

We also carry silica sand and many other specialty sand for water filtration applications.