I've been looking everywhere for chick-sized grit. Our pet stores sell canary sized grit but it's all high calcium. None of the feed stores carry it - the one I went to today doesn't even sell regular sized grit. I was told that because our soil is sandy no one here uses it. I do have a box top with dirt in it in the brooder for them to scratch and bathe in. Is this sufficient? The chicks are 3 weeks old and look forward to greens and such every morning. I originally found decorative "organic" sand for little sand/rock gardens and such, but I'm out of that now. How old till they can use "regular" sized grit, assuming I can find any?