We need a hydro cyclone , I came across this in the engineering field used for cleaning cutting lubricants on grinding machines, Dyson vacuum cleaners use the same principal I think. the liquid enters a cone in a circular motion, it travels down the cone, at the bottom the heavies drop out (that our particulate) and somehow the now lighter liquid travels back up the inside of the cone clean and without the particulate, easy ! if only I new more about it !!!!!!