Approx price: 14/Kg Minimum Order Quantity: 50000 Kg 12/20 or 12/40 coarse grains are widely used in water filtration applications such as Industrial waste water treatment and commerical water filtration. Garnet is the most cost effective alternative for waste water filteration beds as it resets the filter bed more rapidly after the bed is back-flushed. It is effective for elimination of heavy minerals as well.