Poly Quat Question

sunnydays

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Apr 16, 2007
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Bucks Count PA
#1
After a couple of hours adding my weekly dose of Poly Quat 60 my testing of FC dropped 4ppm. I remember reading that some people experience the drop when doing closings last season.

When should I bring the levels back up should I wait a certain amount of time before rasing the FC?

Does Poly Quat need the lower chlorine level to work initially?
 

NWMNMom

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Apr 8, 2007
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#2
I don't think it NEEDS to, it just does. The chemical uses some part of the the FC up. It just does. You make an adjustment for that. I believe it is appx 24-48hrs after applying the PQ, that its done doing its deed to your FC level and you make your adjustment from there. The amount of time may have something to do with the water temp? not sure. Look at the threads on closing for the season, I'll bet exact directions are there.
 

duraleigh

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Apr 1, 2007
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#3
Sunny,

Someone who uses poly will answer your question better than I can. I do seem to remember others reporting the FC drop, too, but I'm not sure. I can think of no logical reason but logic has never been my strong point :lol:

I am not a big fan of polyquat. While it certainly works, so does adequate levels of chlorine. Being somewhat of a cheapskate, I opt to go with chlorine only.

I would bring the FC up immediately.

Polyquat, I believe is effective regardles of chlorine level.
 

sunnydays

Well-known member
Apr 16, 2007
73
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Bucks Count PA
#4
Thanks. I did bring up the FC when I realized how low it got. This was the first time I noticed the dropin FC because I don't normally test the water the same day I add the poly quat.
 

chem geek

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Mar 28, 2007
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San Rafael, CA USA
#5
Moderate to high levels of chlorine break down polyquat, but only turn it into shorter chain polymers that are still effective. That's what the chemist at Buckman Labs told me (they make virtually all the PolyQuat used in the U.S., sold under a variety of brand names). Their recommendation for using PolyQuat upon closing a pool for the winter is to first shock with chlorine and then when the chlorine drops to normal levels, then add the PolyQuat.

As duraleigh said, PolyQuat is more effective at preventing algae than battling an algae bloom and its an extra expense that is unnecessary if you maintain chlorine levels. So if you believe you won't be able to maintain chlorine levels in your pool consistently and you have a bigger wallet, then a weekly maintenance dose of PolyQuat is insurance. Most pool owners that use chlorine or the BBB method to save on cost only use PolyQuat on closing in the winter, if then. I don't use it at all anymore, but my pool does not freeze over in the winter so I just keep chlorine in it (which is easy when the water temps are cold -- the chlorine lasts a LONG time).
 

chem geek

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Mar 28, 2007
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San Rafael, CA USA
#7
That's possible, though isn't anything the chemist wrote about. There are sites where chlorine could not only cleave the PolyQuat polymer, but attach to it (probably to a nitrogen site) and that would probably register as combined chlorine. I suspect that with exposure to sunlight, such chlorine attached to PolyQuat would breakdown and no longer measure as CC -- just like most other organics. Presumably, the relatively low normal levels of disinfecting chlorine and of PolyQuat end up reacting slowly enough to no longer measure as CC nor breakdown FC noticeably, but the remaining fragments are still effective as an algaecide (though may be less effective as a clarifier).

Richard