uses for bark / DE / granite dust?
When all the gritty mix ingredients are screened through insect screen, what do you do with each of the three kinds of dust?
I've seen recommendations to use bark dust where peat would be used. Is it because bark is somehow better - or is it because it's already there? Peat is pretty cheap where I am, so if it's even a little better, I'd skip the bark.
I've also seen advice to roll seeds in DE/Turface dust before planting, so that moisture is retained close to them and so they germinate easier.
Any other gardening- or not related uses of these dusts? I only have indoor space.