ok substrate test inprogress.

[StirCrazy]

Colour, Cost and... thats probably it. well if you look at the perfect composition for a dsb by Dr Ron the dolomite is probably a little better as it has more fine stuff in it (according to his chart even sugar sand is overall to coarse) but that is just one brand of dolomite I don't know the sizes or compositions of other brands.

for me thought.. it is cost and colour.

Steve