Can chickens use sand as grit, or is it too fine? I'm not talking the real smooth stuff like you'd see in one of those desktop rock gardens, but rather the heavy coarse stuff that you get in tubes for putting in the back of pick-up trucks for traction in winter and mixing for concrete and stuff. The reason I ask is that I've been carrying around tube sand in my truck for three winters and the packaging is clearly not going to last for a fourth. I figured I could dump the sand into a bucket, wash it several times to pull out any salt residue that might have been thrown up in the bed (though frankly, I can't see there being any in the actual sand; it's been wrapped in plastic all this time) and float out the really fine stuff, then give what's left to the birds. We seem to have a really loamy soil, and it doesn't offer much in the line of small rocks.