5th November 2011 at 2:03 pm #806
My measurements on volcanic sand in Costa Rica indicate that you get up to 40 % passing a 0.15 mm (100 mesh) sieve. this should not be more than 10 %. Hence, this sand is WAY too fine. It will give a very low throughput and probably well below the 10 cm/hour (100 liter/m2 of filter surface and per hour.