That is quite possibly the worst substate you can possibly have lol. Vita sand is the same as calci-sand, which is horrible. It has things in it that make beardies want to eat it, but one it's ingested it's deadly. It hardens in their stumach like cement, which, as you can imagine, isn't exactly a good thing.
We always recommend non-partical substrates such as paper towels, slate tile, non-adesive shelf liner, or newspaper.
But if you have your heart set on sand, at least use just regular playsand (but I still wouldn't recommend ANY sand)