1. Calculate the anthracite diameter for a deep-bed anthracite filter of 1.5 m with a porosity of 42%. The clean-bed headloss is 1.8 feet at a filtration rate of 13.5 m/h and the temperature of 10C. Ky= 228, Kj = 4.4. 1. Calculate the anthracite diameter for a deep-bed anthracite filter of 1.5 m with a porosity of 42%. The clean-bed headloss is 1.8 feet at a filtration rate of 13.5 m/h and the temperature of 10C. Ky= 228, Kj = 4.4