Pool numbers before closing


Jun 12, 2015
Springfield/ MO
My pool closing is scheduled for this Thursday. I noticed last year they put in 4 gallons of 12.5% chlorine (yes I should have asked before they did anything last year). I suspect that is why I'm seeing significant fading on the bottom of my vinyl liner when I opened this summer. The liner just finished it's 6th summer, it was a medium blue Tara liner installed in 2015. Although I had noticed fading last year, when I opened this year the fading was significantly worse. I'm sure my cya was low or at zero when I closed. The pool store has indicated it's because I don't keep CYA high enough, I try to keep it up at 30 during season, but once no one is swimming I'm guilty of it dropping The pool only has direct sun for about 4 hours a day but the hottest part of the day. I have little to no fade on the walls, weird it's just the bottom. The pool sits on the East side of the house. I pour the bleach in front of my return jets, and keep my chlorine range between 2 and 6. Any thoughts on the fade? I've always used the TFP method with this liner.

Here are my current readings:

FC = 0
pH = 7.8
TA = 110
CH = 175
CYA = 0
Temp = 54

We have a mesh safety cover, is it fine to leave chlorine and cya at 0 and ask the pool store to not add chlorine and only algecide. The receipt from last year says they added Pool Open Complete (1 qt) no idea why when this was a closing, and Regal Algaezone Plus, 1qt.

Or should I just get polyquat and do that myself and not have them add any chemicals, just blow out the lines?

Thanks for your input.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
4 gallons of 12.5% chlorine in your 19,000 gallon pool will raise your FC by 26 ppm. That is a lot with CYA 0. It is perfectly fine with CYA 70.

You can:
  • Add 11 lbs of dry stabilizer to raise your CYA before closing
  • Have them add only 5 ppm of chlorine with your CYA 0 at closing
  • Add PQ60 before closing and no chlorine
Anyone of those will work. Depends what works best for you.
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