Replacing DE in filter

nupoolsoon

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Jan 7, 2008
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#1
Our pool has been open for just over a week. We usually like to replace the DE after a week and all the junk is gone in the pool. My question is, I just added more CYA yesterday and I do dissolve it through a sock in the skimmer basket. Typically they say do not back wash your filter for 24-48hours after you add CYA, but since the CYA is already dissolved before it gets to the filter, is it ok to go ahead and change the DE tomorrow?

Thx!
 

PSW

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#2
The primary reason you don't want to backwash right away is because you just spent time and money adding CYA to the pool, only to wash away most of it.

I would recommend dissolving the CYA in a sock in front of a return jet (not the skimmer). This will send the CYA into your pool first, not your pump/filter.
 

nupoolsoon

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Jan 7, 2008
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#3
I understand the reasoning, but if it is dissolved in an actual tube sock, in a skimmer, there is not much difference from your way. The CYA doesn't come out of the sock unless dissolved, goes right from the skimmer, which we have skimmer socks on the baskets too, through the filter back into the pool. There are not little "crystals" coming out the sock, it is white liquid per se.
 

PSW

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#4
I understand that, but if you are back-washing your filter, then you are sending the CYA straight from the skimmer to the pump/filter (and losing it). You will keep more of the CYA in your pool if it was in front of a return.

Or at the very least, I would take the CYA sock out of the skimmer during the backwash process.
 

nupoolsoon

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Jan 7, 2008
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#5
Sorry for the confusion, but there is no CYA left in the tube sock. The sock is empty which means it has all dissolved into the pool (thru the filter).

I thought that "pre"dissolving through a sock meant the CYA "crystals" would not be stuck to the filter element...is that not correct? If I was to open our filter, would I see "crystals" inside or is all of the CYA dissolved already?
 

JasonLion

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May 7, 2007
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Silver Spring, MD
#6
CYA breaks down into finer and finer bits before it completely dissolves. A sock with CYA in the skimmer basket will let some CYA into the filter. A sock hanging in front of a return jet will not let CYA into the filter (well, perhaps a little if you have a floor drain, but close to none).