Depends upon water quality. ...

Depends upon water quality. Range of 0.15 – 0.35mm, and that the uniformity coefficient should be in the range of 1.5 – 3, although a coefficient of less than 2 is desirable.The homogeneous sand filter has a 0.9–1 m deep bed and typically of 0.85–1.7 mm of sand (effective size 0.9 mm) placed on a 50 mm layer of 4–8 mm or 75 mm of 6.7–13.2 mm gravel. Homogeneous sand of effective size up to 1.3 mm has also been used. Please see attached table.

Regards,