I'm such an idiot. I thought I was taking such good care of my little flock. Last night when I was buying new sand for the run I noticed a bag of Diatomaceous Earth for swimming pool filters & thought oh yes, I've heard about that stuff, it will help keep the run fresh & clear of pests. So this morning I mixed it in with the new sand ~10 lbs per 200 lbs of sand. Then I read that it's not the right stuff at all! So I'm in a bit of a panic, what have I done?! It's silicon. What will this do to my chickens?