DE For Sand Filter

sktn77a

Gold Supporter
May 16, 2010
762
0
Chapel Hill, NC
#1
I'm using some DE in my sand filter to clear up some cloudiness in my pool water. Chemistry is as follows:

FC 9.0
CC 0.0
CYA 50
pH 7.5
TA 100
CA 300

Looks good to me(?) I added a couple of cupfulls of DE slurries into the filter (making sure it dissolved as a slurry as I was doing this). The DE I'm using is the following:

https://www.amazon.com/gp/product/B00TEDE9GK/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Hasn't done squat - if anything it's getting worse! Also, the pressure hasn't increase at all. I thought the pressure would inclease as the DE coated (clogged) the upper layer of sand in the filter.

Is the DE going straight through the filter and adding to the cloudiness?

Thoughts?
 

tim5055

Mod Squad
LifeTime Supporter
TFP Expert
May 11, 2014
10,081
1
Franklin, NC
www.title-3.com
#2
Is the DE going straight through the filter and adding to the cloudiness?

Thoughts?
Maybe. You purchased the wrong thing. You want pool grade DE, not food grade DE.

I actually use Cellulose Fiber DE Replacement

https://www.amazon.com/Pro-Guard-23793BPG-Cellulose-Replaces/dp/B00D3J3G4W

If the pressure isn't going up, you are NOT increasing your filtration.

Now, on to another issue. Do we know the cause of the original cloudiness? Dull, then cloudy water are the beginning signs of algae. I would say an [OCLT][/OCLT] is in order to eliminate the possibility of something growing int he water. Filters don't remove algae....
 

sktn77a

Gold Supporter
May 16, 2010
762
0
Chapel Hill, NC
#4
Ah, OK, so this stuff won't do anything? What's the difference between food grade and pool grade?

The pool was a little cloudy (milky-like, not green, yellow or brown) beforehand but I had just added stain-free and metal magic, so I assumed that was the cause.
 

sktn77a

Gold Supporter
May 16, 2010
762
0
Chapel Hill, NC
#5
Well, I did a little more research on this and it turns out food grade DE is structurally and chemically different to pool grade DE. Importantly, it is a much smaller size and passes through the sand filter - hence the cloudiness. Oh well, live and learn!