i cannot find "chick grit" at any of my local suppy stores, but i had read on here that sand would work. i have "construction grade" sand on hand, so i put a window screen over a bucket to filter out any bigger stuff, which left me with a bucket of very fine sand. would that be good for the chix? i'm really wanting to give them some "fun food" but i know they need grit for that to happen. plus... how much grit? i figured i'd just put it out and let them have as much or as little as they want. or should i give it to them in smaller amounts at a time? thanx for the info.