Recently Emptied & Refilled Pool: Add Cyanuric Acid (CYA) now before close or wait until spring?


Jul 18, 2012
Philadelphia, PA
We had some coping and tile work done that required us to empty the pool. The pool is now refilled, but we will be closing in a few days. Should we increase the CYA levels before close, or wait until we open in the spring? Current water temp is 57 degrees and all other levels are ok (although I normally keep alkalinity ~ 90 - guess that is from the refill with public water):
FC = 7.0
pH = 7.5
Alk = 130
CH = 250
CYA > did not test, but assume at/near zero b/c of filling with public water
My assumption is the amount of stabilizer (~ 5 lbs) will not dissolve easily in the cold water temperature. Note I have a solid cover for closing the pool. Thanks in advance for suggestions/tips.

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
Texas, San Antonio/Marion, South-Central Area
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
You do want at least 30 ppm of CYA. With no CYA, the chlorine is extremely strong and you don't want that against the liner. Shoot for a CYA of 30. You might try to pre-soak the stabilizer granules (in a sock that you can squeeze) in warm water in a bucket before taking it out to the pool. That might help.


Mod Squad
Gold Supporter
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
I ran the CYA needed amount thru the old PoolMath as I was hoping your pool size would be perfect for one entire jug of liquid CYA. Alas, one gallon is too much :(

So 74 ounces of granular CYA in warm water, per TexasSplash'es recommendation would get you to 30ppm CYA,

I would do this before closing because as you stand now the chlorine in your pool is harsh against your beautiful new pool and equipment.

Maddie :flower:
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