Bill, what you have isn't exactly dry wash media. It is 'magnesol' which is a biodiesel purification agent (a synthetic form of magnesium silicate.) It is mixed with bio then filtered out to remove soaps and other contaminants. It actually works very well but a drawback is that it can go through a 1 micron filter but if settled for long enough it will drop out of the bio.
It also reduces the colour of the bio.
