Cheaper solution for D.E.

[LittleTagAlong]

I love this forum. It has helped me immensely.
I was doing research on D.E. because I want to add just a little to my sand filter. Well, I don't need or want a 25lb bag. I thought maybe the insecticide kind would work. No, the chemistry and process is different. The D.E. for the pool is heat treated to make it more crystallized or calcined. Lo and behold, at Napa Auto Parts, they have a product called "Floor Dry part #8822" that is exact chemical composition of D.E. Filter Product. It is only a little over $8 for 24 qts. Will update weight when I get back with it.

 

[JoyfulNoise]

I don't think this is pool grade DE. First off, pool grade DE is calcined and crystallized silica. It is an inhalation hazard and could never be used in the manner that this product (Floor Dry part #8822) states. Here's a link to an MSDS for the product -

http://nova.saisd.net/storage/uploads/FacilitiesEnviron/sds699

Here's two sections -

INGREDIENT IDENTIFICATION
Diatomaceous Earth, Calcined (kieselguhr)......... 100%
Crystalline Silica (Cristobalite) .......................... <1%
Crystalline Silica (Quartz) .............................. <1%

But then, here in the "Chronic Exposure Section" it says (emphasis added)-

This granular product can contain respirable dust, composed primarily of amorphous silica but possibly with a small fraction of crystalline silica. Amorphous silica is not classifiable as carcinogenic to humans. Crystalline silica, when inhaled as respirable dust, has been classified as carcinogenic to humans over prolonged and sustained exposure. Long-term inhalation of respirable crystalline silica may contribute to the respiratory disease “silicosis”, a non-cancerous lung disease. In a 1997 monograph (Volume 68, “Silica”), the International Agency for Research on Cancer (IARC) concluded that overall the epidemiological findings support increased risk of lung cancer from inhaled crystalline silica resulting from occupational exposure (classified in Group 1), while there was inadequate evidence in humans for the carcinogenicity of amorphous silica (classified in Group 3).

Pool grade DE is not amorphous silica, it is crystallized silica. This is why pool grade DE is an inhalation hazard. My best guess is that they are using the term "calcined" in the ingredient section to refer to process of thermally removing organic matter but it is not processed at a temperature high enough to cause crystallization of the silica. Either that, or they simply made a mistake in the MSDS and should have used the term "uncalcined" instead.

I would caution against using this product and, if you've purchased some, return it. If you put anything but pool grade DE into your filter, you could be in for a clouded pool nightmare which will possibly require draining your pool or using flocs and clarifiers to restore clarity.

On a different note, most pool stores around my parts sell pool grade DE in 10-lb bags. I realize that is still a lot of DE but I don't think it is money wasted if you use it; it does not go bad or expire. It's not that expensive to have on hand but it will be VERY EXPENSIVE to clear a pool that is clouded with DE.

Your call, but I think it's a mistake.

Matt

 

[JoyfulNoise]

Update -

The term "kieselguhr" is German which literally translates as "gravel yeast". It refers to the as-mined product, NOT the heat treated product.

This from the Wikipedia entry on Diatomaceous Earth -

Diatomite produced for pool filters is treated with high heat (calcination) and a fluxing agent (soda ash), causing the formerly harmless amorphous silicon dioxide to assume its crystalline form

 

[MarianParoo]

I plan on bequeathing my DE to my son when I die... Maybe even my grandkids; I have plenty! It only cost me $20 bucks for the 25# box. I bet the pool store box is close in price.

 

[basod]

The big box I bought at Lowes ~8yrs ago for $30(IIRC) is still serving me 2 cups at a time for polishing after I neglect the pool and get an algae bloom.

 

[LittleTagAlong]

Thanks for the input! I was very lucky and irritated that Napa was closed when I got there. Had to go to Walmart&#55357;&#56867; and they had a 10 lb box. Put about 2/3 of a cup, mixed in water, in the skimmer. It kicked pressure up for about 20 minutes. Then I attached my AquaCritter and let them run all night. Looking better this morning.

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[Rollercoastr]

I too have way more than I can ever use. I'd like it give it to a local TFP'er if I could.

I was surprised that something apparently so dangerous is packaged so carelessly: a sloppy bag inside a loose box... If anyone from S.E. Mich to N Central OH wants to share some DE, let me know.

 

[banditig]

I wear a dust mask and mix with water in a bucket. Still get a funny taste on my lips even though I didnt breath it in.

 

[basod]

DE is really not as bad as the warnings state. There are OSHA permissible exposure limits(PEL) for inhalation exposure, you'd have to be around the dust for 8hrs a day everyday to meet a threshold of exposure.
It's one of those things once in your lungs it is near impossible to get out - similar to silica dust, asbestos, cement dust.

As a pool owner you may see a PEL excursion for ~1min while sprinkling in your skimmer (or mixing in a bucket) a few times a year. Just stay upwind of the dust and worry about dying from something else - like old age