Ola Harry
I have another tip for you
Go to the local or nearest petshop and invest in birdcage sand. It comes in bags and packs of different sizes. and it is relatively cheap. It is a fine grain with often some stuff like crushed shells in it but they are not recognizeable as small shells and since groundwork is never consisting of one and the same material it is perfect for doing groundwork.
Years ago I bought a 2 kilo Milkcarton (it really looks like that) and I have used it for all my groundworks up to date and I still have enough for a few lives. Not bad for only 1,50 Euro`s