It's not that simple, what is ...
Published by Derek French, Wateropolis Inc. - Founder
It's not that simple, what is the effective size of the sand (d10) and what is the uniformity coefficient of the sand (d60/d10) and how much head loss is there through support gravel and the under drain system and what flow rate per unit area are you running. There are too many variables to simply give you a number.