Substrate - Dusty?

[MrBosc]

Hi all,

I bought some top soil and play sand for my Bosc and I used a 70/30 ratio. To quickly accomplish this I used a fairly large tin and for every 7 fills of top soil I done I would then add 3 lots of play sand to the top soil. However rather than the Bosc being able to burrow it's pretty much just like dust, what have I done wrong? In addition I should add I have not added any additional water to the top soil (if you have to add it that is)

Thanks for any replies