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Thread: Diatamaceous Earth for Pools vs. an insecticide?

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    Diatamaceous Earth for Pools vs. an insecticide?

    This may be a tough one.

    Last year I had an ant problem in my house and was doing some research on pesticides. It appears Diatomaceous Earth ("DE") is one of the best and least hazardous methods of killing insects, (Beetles, ants, roaches, centipedes, etc.). Diatomaceous earth appears to be made of ground fossils of prehistoric fresh water diatoms. To insects DE is a lethal dust with microscopic razor sharp edges. These sharp edges cut through the insect's protective covering drying it out and killing them when they are either dusted with DE or if it applied as a wettable powder spray. If they ingest the DE it will shred their insides.

    Based on my unscientific research, it appears that both swimming pool grade and natural diatomaceous earth come from the same fossil sources but are processed differently. The natural grades are mined, dried, ground, sled and bagged. The pool grade is chemically treated and partially melted and consequently contains crystalline silica which can be a respiratory hazard.

    My question is; does anyone know if this is true or just another ploy to buy more expensive DE?

    BTW For once, it appears to be cheeper for the pool then as an insecticide.
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    Mod Squad JohnT's Avatar
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    Yes, it is true. I think a lot of the claims for DE as an insecticide are exaggerated.
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    midtngal's Avatar
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    Interestingly enough I was just at Lowe's yesterday and saw this DE in the insectiside section and wondered if it was the same thing. Are you saying that it is and can be used in pools? I was looking for some to add to my sand filter after reading the benefits of doing so.
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    Mod Squad JohnT's Avatar
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    Quote Originally Posted by midtngal
    Interestingly enough I was just at Lowe's yesterday and saw this DE in the insectiside section and wondered if it was the same thing. Are you saying that it is and can be used in pools? I was looking for some to add to my sand filter after reading the benefits of doing so.
    No. The pool DE is processed.
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    Thanks John! Why do you think the claims for DE as an insecticide are exaggerated?
    -400 sq ft ingroung Fiji (straight back kidney) ~ 13,500 gallons - Vinyl Liner - 3 to 6 Feet
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    Mod Squad JohnT's Avatar
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    Quote Originally Posted by Craig
    Thanks John! Why do you think the claims for DE as an insecticide are exaggerated?
    There are a lot of claims. I do think it works in some cases, but there are many, many unsubstantiated claims about it. Almost treated as if it is magic by many organic producers. I guess many of them would be easy enough to test, but there aren't a lot of test results. It used to be a widely held believe that feeding it to livestock would eliminate the need for parasite treatment, but there are no studies showing any significant effect.
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    First post after lots of lurking and learning.

    I'm looking to add some DE to my sand filter (after an algae bloom, I just can't get the water to sparkle. It looks like Lake Louise!).

    However, in my town, the ONLY diatomaceous earth I could find is sold as a "green" insecticide. I couldn't get "pool grade" DE at the pool store, Wal Mart, or anywhere. The label tells me that it's "97% Silicon Dioxide. Contains only Diatomaceous Earth and food grade attractants." (Doesn't sound any worse than 99.9% of the stuff the kids put in the pool!)

    Soooo....Can I use it?

    Thanks!

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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    I looked into the same thing. Apparently there is a difference between the pool type and the type for gardening as used in greenhouses. The gardening type is supposed to be less refined and have sharper edges if examined microscopically. Not saying this is fact, but I read it in several different places.
    Geoshecks
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    I really do not know if there is a real difference or just the claimed difference, but nonetheless if you are having difficulty finding DE locally, order it on line. I have had very positive experiences ordering for In the Swim or Doheney's Water Warehouse. Both sites have very reasonable prices.
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    They are different. Pool DE gets heat treated, which causes it to contain far more crystalline silica. Crystalline silica is a respiratory hazard and a carcinogen when breathed in. It is pool DE that has all the sharp edges.
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    Thanks for the clarification. Unfortunately, I live in Canada. Well, okay, that's not unfortunate, except when it comes to buying things online. I can't find a company that will ship the DE to me without RIDICULOUSLY high shipping charges.
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    My understanding is that it works as an insecticide primarily as a dessicant.
    http://www.ehow.com/how_4470217_cockroa ... -ants.html

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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    Interesting enough it mentions that DE is used for swimming pools and to kill insects but never makes a distinction that there are two different types. It also states that it is safe.

    I tend to believe that there are two different types based on manufacturing and neither is safe.
    -400 sq ft ingroung Fiji (straight back kidney) ~ 13,500 gallons - Vinyl Liner - 3 to 6 Feet
    -Hayward 1.5 HP Super Pump
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    -Hayward H 250 Heater

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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    Jason,
    Thanks for setting me straight!
    Geoshecks
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    The WikiPedia article, while not a truly definitive source, does explain the difference fairly well, if perhaps to technically. Neither version is completely safe, but then most pool chemicals are not completely safe.
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    DE certainly can be used as an insecticide. It is the best thing to use for snails and slugs, and though it washes off in the rain it will tend to build up in the soil as you reapply it until after a yeaer or so the snails and slugs simply don't come around. I read that it is also useful for grub worms if you scratch it into the soil. And for spider mites if you dust it into the webs and around the plant. Sure helped the plants that I used it on but it looks like I need to reapply after a month or so. I also read that it is useful for de-worming pets and comes in pill form for that use.

    The garden variety of DE is way more expensive, at least in the organic gardening shops where I see it. Being cheap, I bought the swimming pool grade for garden use and eventually found that working in that garden irritated my lungs. Might have been mold and mildew, or maybe the DE, I dunno. Now I go on and buy the garden type of DE.

    So, with that info, I do wonder when you guys with DE in the filter do the work to clean it, do you take precautions against breathing it? And, do you find that dumping the mix on the ground has ever prevented damage in the lawn from insects like grub worms and cinch bugs and snails?
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    Just to chime in...
    I used to have a de filter system. The need for proper handling of the material convinced me to switch back to a sand filter.
    Although the de system did produce better filtering results than the standard sand filter, I did not wish to continue confronting the potential hazards of using de, both personal and environmentally. Also, the cleaning of the filter screens was a maintenance nightmare. When I switched back to sand, I made it a point to use Zeolite, instead of the standard sand. The Zeolite produces results just as good as the de, but without the hazard and maintenance worries. If you take the time to properly maintain your pool, by following the advice offered elsewhere on this forum, you will be very pleased with the results, without using de.
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    Re: Diatamaceous Earth for Pools vs. an insecticide?

    There are DE alternatives for DE filters that work quite well. I started using Fiber Clear this year and so far am quite happy. It is an extremely fine powder made from wood cellulose - not supposed to have the health problems that DE does, but probably not an insecticide either!

    There are some caveats - Fiber Clear absorbs oils that DE does not, so that helps clear the water but also may require more frequent back washing. It is more expensive (but you use less, so it is not as expensive as it appears). Some folks have said that it continually clogs, I have not had that problem. On the plus side, if you have a DE filter, it is much cheaper to switch than to buy a new filter....
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