Where to do CYA test

Bvacchiano

Well-known member
Apr 6, 2018
98
Houston
#1
Just curious WHERE people on this site perform the CYA test? Reason I ask is I can see different results if I do the test on my light travertine decking versus doing in the grass. Yes I do at high noon with my back to the sun, etc. I follow all the guidelines specified here.

I find the CYA test pretty bogus anyway. I’m confident we could get 5 people to test the water and get five different answers. I just fill to 90 and if I can see dot I’m happy. Then I fill to 50 and if I can’t see dot I’m happy because I’m between 60-80 and just keep FC at 6. (For SWG anyway)
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#2
I perform my CYA out back on my flagstone path. But that's not because I expect the ground below me to influence the visibility within the viewing tube. Unlike a pH test through the OTO viewer, I've not experienced any difference on the CYA test. I have seen differences if I hold the tube itself differently. The position of my fingers around the tube can skew my results. But when I do the CYA test, I do it several times to where I am confident in my CYA result within 10 ppm.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,535
Bedford, TX
#3
B,

In my opinion, knowing your CYA is between 60 and 80 is close enough for good pool management...

I also agree with your 5 different people theory... But the whole point is for you to run the tests in the same way each time, so that you end up with the about the same answer each time.

I use a sliding dot test kit and find that for me, it is much more repeatable..

Thanks,

Jim R.

Jim R.
 

MyAZPool

Gold Supporter
Jul 3, 2018
302
Chandler, AZ
#4
B,

In my opinion, knowing your CYA is between 60 and 80 is close enough for good pool management...

I also agree with your 5 different people theory... But the whole point is for you to run the tests in the same way each time, so that you end up with the about the same answer each time.

I use a sliding dot test kit and find that for me, it is much more repeatable..

Thanks,

Jim R.

Jim R.
Jim,
This is an interesting thread, as the CYA test in the TF-100 is the one test that drives me a little nuts, as I strive for consistency and try to get results at least within the "hand grenade :D" range. Can you please share a little more info regarding the "sliding dot test". Maybe switching over to that test, will help save me from explaining to my neighbors why I was using "colorful" language while I conduct my routine pool chemistry testing. ;-)
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,535
Bedford, TX
#6
Guys,

I have this Pentair test kit.. Amazon.com : Pentair R151226 79 Cyanuric Acid Test Kit : Swimming Pool Liquid Test Kits : Garden Outdoor

It appears to be a clone of the Blue Devil test kit.. I use Blue Devil reagent...

I am not saying it is better for everyone, just me... :p

The downside is that is uses much more reagent... the upside is that the volume of the pool-water/reagent never changes... You just slide the "dot" up and down, so that you can repeatedly make the dot appear or disappear. I doubt it is any more accurate than the test in the TF-100, I just find it much easier to use and my results are more constant.

It works the same way... with no CYA and the dot at the bottom of the tube, you can still see it.. With about 100 ppm of CYA, you have to bring the dot up near the top of the test tube to see it..

Thanks,

Jim R.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,331
Sebring, Florida
#7
B,

In my opinion, knowing your CYA is between 60 and 80 is close enough for good pool management...

I also agree with your 5 different people theory... But the whole point is for you to run the tests in the same way each time, so that you end up with the about the same answer each time.

I use a sliding dot test kit and find that for me, it is much more repeatable..

Thanks,

Jim R.
A great big PLUS ONE to this post. This test is the most over thought test that we use. We stress over the lighting, cloudy days, fingers position, etc. all trying to get a precision that the test simply does not provide.....regardless of how many tips and tricks you try.

Perform the test by following the instructions provided and then, if not comfortable with that result, pour the solution out of the view tube and then back in several times. Take the average of your observations and that is your CYA.

Sliding dot or the 9193 found in the TF-100, they will both give you results that are within the degree of precision we need.