Estimating pool volume and high CYA issues.


LifeTime Supporter
Jul 29, 2008
San Antonio, Texas
Pool Size
Liquid Chlorine
My new (to me) pool had an initial CYA of 100 and we all agreed to drain enough water to get the CYA closer to 50.

The pool volume was rumored to be 15,000 gallons but that seemed high to me. It is a very irregularly-shaped pool that is never more than chest high.

I drained out about half by the eyeball method and refilled. My CYA is now 50. So far so good.

I have a Flume water meter (Highly recommended and almost completely paid for by my water company rebate!) My Flume meter says the quantity of water used to refill half my pool was about 4,500 gallons.

Do I declare my new pool volume as 9,000 gallons going forward when I add chemicals and see how it goes?

I have a 55 pound tub of boric acid on the way.



Gold Supporter
Bronze Supporter
Nov 30, 2019
Pawleys Island, SC
Pool Size
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Believe your meter. Published volumes are notoriously inaccurate. My pool builder and the manufacturer both were not even in the ballpark. I was told 14K gallons when it tests/doses at barely 7K with PoolMath.
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