https://www.youtube.com/watch?v=fBKlXDx6txo
Flow rate and operation of slow sand filter explained along with gradiation of fine sand and gravel below the source water.
Flow rates of 0.015-0.15 gpm/ ft^2 expected for typical performance with entry water of < 10 NTU..
Two day period of establishing Schmutzdecke Algal layer on the surface of the slow sand filter is explained and
how that period se