I used DE from the pool supply store this summer. Someone on Gardenweb warned me afterwards that the pool grade DE has something in it that should not be inhaled. Honestly, I would avoid inhaling any fine powder! It does work to deter Japanese beetles. I dusted my raspberry plants and green beans with it, either in the morning, while the plants were still wet with dew, or after a misting with the hose. I made something like a big salt shaker by drilling holes in the lid of a peanut butter jar, filling the jar with DE, and shaking over the plants. There's almost always some light breeze, and I stand so the DE drifts away from me. I doubt DE will scratch the beetles deeply enough to bother them. Rather, I think it gets into their joints or their mouthparts to cause trouble or discomfort. I haven't found a bunch of dead beetles under the treated plants, just not nearly as many on the plants as usual. However, it may be that the DE kills the first few beetles which heads off the orgy swarm later. Alex

I appreciate the reply and learning a bit more about the site see you've participated in some discussions re: diatomaceous earth. If you're willing, I'd appreciate the benefit of your knowledge on my intended use for the DE. We have two dogs and believe we have ticks in our yard. Not surprising since we hike frequently and can never remove ALL ticks. Ugh! We live in the suburbs, have a wonderful garden... we have quite a few critters that frequent the yard as well as call it home... birds, squirrels, toads, earthworms... we applied nematodes this spring to help with the flea population we believe exists as a result of the numerous squirrels... my questions, will we be doing more harm than good (to our general insect population) by spreading DE? Will the DE destroy the nematodes?

If it does not explicitly say food grade then do not assume it is. When I bought DE last spring the Safer brand DE was not food grade nor does Safer represent it that way. I read one online review, I think that it was on Amazon, where a person liberally applied the Safer DE around her house, her pet ingested it and the pet died. The way I interpret it, non-food grade DE like the Safer brand is probably a safer choice vis a vis blasting your home with Raid or something like that if you are trying to control insects, but it is not a completely safe for pets. I would feel comfortable putting it behind appliances or in cabinets where most pets don't roam, but I would not put it in a place where a pet can walk over the DE and then lick it's paws or lay on and then have the substance on their fur where they can either lick or inhale the DE. FOOD GRADE DE is safe for pets including putting it in your pet's food, it can be used as a de-wormer but you have to make sure that it is food grade(!!!!!!!!) and of course you use the right dosage. I also agree with the caution noted above that, even with food grade, the dust can be an irritant, so you also have to be careful with even food grade DE to probably keep your pet out of the area while you are applying the DE and give it time to settle.

I don't think DE kills slugs. Slugs do avoid it as they do any rough surfaces. Eating it may provide some calcium as it is skeletal, and may provide some roughage, but eating fiber and drinking milk would seem to be more effective than eating DE ??? In any event, if anyone wants to experiment by eating it, they should certainly ensure it is food grade from a reputable source. In small doses I think it is harmless and, however, IMO useless in anyone's diet DE is sprinkled on top of worm 'farms' to deter insects. Larvae will hatch. It is claimed that when they hatch the rough edges scratch the hatched fruit flies or other pests and they die. I don't know, maybe they just find it annoying and leave. It most likely keeps adults away from it and prevents more larval production. In any event worms do not digest DE. Small amounts simply pass through them harmlessly. It is not worm food. It is sprinkled on the top of worm beds not mixed into the soil. Jon