1. ## Question about lowering CYA

As I am draining my pool can I test the water for CYA or do I have to drain then refill then test with pool full of water. Finally biting the bullet and lowering it. I used the pool math calculator and it says 50% so that's roughly where I am going with it. Thanks!

2. ## Re: Question about lowering CYA

Originally Posted by GinaLovesSummer
As I am draining my pool can I test the water for CYA or do I have to drain then refill then test with pool full of water. Finally biting the bullet and lowering it. I used the pool math calculator and it says 50% so that's roughly where I am going with it. Thanks!
You're testing for relative levels of CYA. Less water with no other changes = same relative level of CYA. Like when you're testing the level in the pool by using a small sample of water. So 1 ounce of that water is the same as 10,000 gallons. Unless you introduce new CYA-free water to dilute the overall CYA content of your pool it will always read the same.

3. ## Re: Question about lowering CYA

Originally Posted by GinaLovesSummer
As I am draining my pool can I test the water for CYA or do I have to drain then refill then test with pool full of water. Finally biting the bullet and lowering it. I used the pool math calculator and it says 50% so that's roughly where I am going with it. Thanks!
No sense checking the remaining water, it will be the same as the CYA is evenly distributed throughout.

Check it after you complete the refill.

4. ## Re: Question about lowering CYA

Originally Posted by GinaLovesSummer
As I am draining my pool can I test the water for CYA or do I have to drain then refill then test with pool full of water. Finally biting the bullet and lowering it. I used the pool math calculator and it says 50% so that's roughly where I am going with it. Thanks!
It hurts now but you'll be a lot happier when all that excess CYA is gone.

5. ## Re: Question about lowering CYA

That's what I figure. Might as well get it right and slam properly so that when I close for the winter I am not kicking myself for not lowering it. In the beginning of the summer I was being pool stored and that's why I have a CYA of 110. I read it wrong when I first started testing. I figure fix it right this year and hopefully be running smooth next year.

6. ## Re: Question about lowering CYA

The good news is right after I finished draining what I wanted we started getting flooding rains so the pool filled super fast! Woo Hoo! Gonna wait for the sun tomorrow to retest my CYA!

7. ## Re: Question about lowering CYA

EXCELLENT planning!

8. ## Re: Question about lowering CYA

Where did your CYA end up, Gina?

9. ## Re: Question about lowering CYA

It ended up at a 60 which I figure at least I can manage for the rest of the season. Plus I will drain part off to winterize once the water gets consistently down to 60 degrees.

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