Does winter (midwest) impact CYA levels?
This will be my first year closing my AG pool and was wondering if the winter weather will have any impact on my too high CYA of 100? As I have been learning from this forum the best way to reduce CYA is to do a partial drain, but I was wondering if I should do it before closing or in the spring or will the cold midwest winter impact CYA?
Thanks
Re: Does winter (midwest) impact CYA levels?
If you let your pool water go South (ignore it) there is apparently a process that, because of the big load of organics in the pool, will eat up most, if not all, of your CYA.
That has never seemed too good an idea to me because you have to clean up a murky pool in the Spring as well as add new CYA. Drain and refill seems a far better choice.
Re: Does winter (midwest) impact CYA levels?
My understanding (although being a newbie I could be wrong) is that once we properly close our pools here in the freezing midwest we don't touch them again until spring. I'm sure it's different in NC with your much warmer winters.
So my question is assuming I properly close my AG pool will CYA be signifantly impacted by the winter (reduced from current 100 level)? or will I need to drain and fill to get my CYA down?
Thanks Again
Re: Does winter (midwest) impact CYA levels?
I believe the process Dave was referring to is that there are certain anaerobic bacteria (that is, bacteria that do not need oxygen to survive) that actually consume CYA. In fact, CYA is considered to be somewhat bio-degradable in the environment (soil) for this reason.
However, if you "properly" close your pool by adding a large amount of chlorine to it, then the bacteria that consume CYA will not survive the chlorine. On the other hand, if you "let your pool water go South" by not adding chlorine to it, then you may get the sort of bacteria in your pool that consume CYA so that when you open up in the spring your CYA levels may be lower (but your pool will likely be full of green algae and need a lot of cleanup). Many users of this forum do seem to startup their pool in the spring looking pretty full of algae and they just shock it to clean it up.
So your options are either to drain and refill (a certain way to reduce CYA) and keep your pool "clean" during closing by adding lots of chlorine, or don't add any chlorine during closing and "hope" that the CYA gets consumed. It's possible that even adding chlorine at the start of closing won't be enough to keep your pool clean as it the chlorine could get consumed over the winter season (this depends on what goes on in your closed pool over the winter).
Richard
Re: Does winter (midwest) impact CYA levels?
Got it . Thanks very much for the replies, I think I'll wait until spring to do my drain/refill assuming CYA is still too high.
Re: Does winter (midwest) impact CYA levels?
Quote:
Originally Posted by chem geek
However, if you "properly" close your pool by adding a large amount of chlorine to it, then the bacteria that consume CYA will not survive the chlorine. On the other hand, if you "let your pool water go South" by not adding chlorine to it, then you may get the sort of bacteria in your pool that consume CYA so that when you open up in the spring your CYA levels may be lower (but your pool will likely be full of green algae and need a lot of cleanup).
Then there are some of us who do close properly and who open to clear pools, (not green, no algae) and yet still have lost all the cya from their pool over the winter.
Re: Does winter (midwest) impact CYA levels?
Watermom,
Just curious, but was there a measurable chlorine level when you opened up your pool and found the CYA was gone? Perhaps the chlorine level went away, the bacteria ate the CYA, but it was too cold and not sunny for algae to form???
Richard
Re: Does winter (midwest) impact CYA levels?
Yes, I always have cl upon opening. This has always been the case for my pool. Always open to clear water.
Re: Does winter (midwest) impact CYA levels?
Great, another mystery to solve! Namely, how does the CYA go away over a winter closing when there is chlorine in the pool that should prevent bacteria from eating the CYA. Does the CYA breakdown due to the cold? Does this bacteria survive chlorine? Who knows?!
Thanks for the info.
Richard
Re: Does winter (midwest) impact CYA levels?
I second Watermom. I open to clear water and chlorine. However, my CYA level is always significantly lower when I open than it was when I closed. This year I opened and had no measurable CYA at all. The pool is generally closed for 6-7 months out of the year and basically frozen for 3-4 of those months, depending on the winter.
Jean