Actually another, unrelated conversation with a Bonsai Professional from Japan, has led me to think about planting certain types of trees in 100% "river sand", my fear is that I haven't shrunk the pot size on some of the trees that might thrive in that media to where I and a friend might be able to carry them..... But who know.
On the other Front, just bought another couple of hundred bags, with blending and the relative reduction in tree numbers without a "nursery" anymore, that should get me up in to my 70's. Unless I croak from Silicosis from so much sifting and using dry mix.....