Proper Measuring for CYA Question

[davisito45]

Hello everyone! I am on the verge of doing a 1/3 drain on my pool due to high CYA readings.

I did my first CYA test with the Taylor Kit 2006 and the results were 120 ppm. Then I read this article http://www.taylortechnologies.com/ChemistryTopicsCM.ASP?ContentID=36 and followed their steps and came up with 60 X 2 = 120ppm. I am postive the CYA is at or near 120ppm.

I went to Leslies Pools and had them do a CYA test and they came up with 40-50ppm.

Please advise on the accuracy of CYA tests.

My results:

PH 7.5
TA 80
FC 11
CC 0
CH 310
CYA 120

Thanks!

 

[Buggsw]

Frankly, with the CYA test, it's hard to say which one is accurate. So many people have a difficult time reading that test. I know that I do.

Personally, I've had very good luck using Leslie's to test my water. Here's what I would do. Have your water tested a couple more times. At Leslie's by another person or at another Leslie's or even other pool stores, if you wish. Though, I find it's other pool stores who seem to be wildly off, especially if they use electronic testers, which may be out of calibration.

I'd hate for you to dump water needlessly or dose your pool incorrectly.

 

[PaulR]

Are you absolutely certain the black dot is completely obscured? Try wiggling the tube a little, sometimes that makes you notice the dot again. Perform the test outdoors during the day, in the shade; if your light is too dim the test will read incorrectly high.

It is true that the level of training, expertise, and care exhibited by pool store employees varies widely. You are almost certainly being more careful than they are; but in this case the discrepancy is so huge it's worth verifying as Buggsw suggests.
--paulr

 

[257WbyMag]

Assuming that you followed the instructions to a tee, I would tend to believe your CYA testing results over the pool store's.

The CYA test tends to be one of the toughest for folks to learn how to read since it is a turbidity measurement and not a color comparison. I'm with PaulR when he suggests performing the test outside in the shade. I do my CYA testing outside, on a bright and sunny day, in the shade. If I don't have those conditions, then I wait and test when I do have them. It's consistent that way.

 

[frustratedpoolmom]

Assuming that you followed the instructions to a tee, I would tend to believe your CYA testing results over the pool store's.

Me too.

 

[Buggsw]

You can follow the instructions to a tee and still be incorrect. Poor eyesight, perhaps even the beginnings of cataracts or other vision problems can contribute to an incorrect test reading.

 

[Guest]

Having worked in pool stores and knowing the competency of the average pool store employee AND the type of training they receive I would trust your test over Leslies, bad eyesight or not!

 

[davisito45]

Thank you for your replies.

I agree that the CYA test is difficult due to the variations of poor vision to great vision of the eyes. I will have the CYA levels tested at a different Leslie's store and see what results I get. My wife also did the test and came up with the same results as myself 120ppm.

Your support is appreaciated

 

[chris4150]

Let us know what your next Leslies test results are. I can profess to the possible errors of CYA testing at pool stores. For example, I just had my pool refilled and decided to have my water tested, despite having my T-100 kit, and I was told my CYA was 60

Now, for most of us here on TFP, a reading of 60 seems a bit extreme since I just filled my pool with fresh water. So I decided to to test my pool water myself via T-100 and my CYA was 0 as expected. The water in the tube was completely clear. Just goes to show.

 

[davisito45]

Update on my CYA levels.

I just had Leslie's Pool do the CYA test (I went to a different location this time) and they tested my CYA level at 100. Thanks for all of your help....this is a great forum.