I haven't found food grade diatomaceous earth locally. I found non-food grade DE at Country Max, but there's 1% "other" in the ingredient list, and I wasn't sure if that was OK. The local health food shop sells it in the pet section, and I wasn't sure if it was food grade or not, but the price was like $16 for a little shaker that would hardly do my coop once. Where can I get it online for a decent price? I have done searches, but the shipping is so variable, that it's hard to get an apples to apples comparison. I figured some of you have already done this homework and would probably be willing to share notes.