CYA (Stabilizer) Testing Question

[Puertex]

Hello,
I understand that CYA protects Chlorine by providing a shield on the surface of the water. (Correct me if I am wrong). If CYA does not mix homogeneously with water, then what is the best depth to sample it for testing. It seems to me that the deeper you collect the sample the less CYA will be sampled. What is the best depth to collect the sample at? Thanks !

 

[Donldson]

You are wrong (hey, you told me to correct you ). CYA is mixed equally throughout the water, what it does is bind to the chlorine which buffers its strength and protects it from UV degradation. You can take sample from any depth, though a foot below the surface is the standard instruction.

 

[Isaac-1]

What he said, that bit about floating on the surface acting as a sunblock is a myth that pool stores have been spouting out for decades

 

[Puertex]

Thanks for the information !!!. I have been wrong before but it was a long time ago I had a 100+ CYA and recently drained near half my pool to lower it. I am injecting bleach and adding no CYA but I believe I am losing too much chlorine. About 2.6 ppm during sunny days in Pearland Tx. My CYA now is 30 and want to increase it to no more than 40 ppm. Since the Taylor test is so tricky I wanted to make sure I am collecting the sample correctly. Thanks to all.

 

[pooldv]

Once summer gets here you might want your CYA up around 50 in that TX sun.

 

[Isaac-1]

Don't worry the test gets easier with practice, but you may want to make sure you don't have something trying to grow in your pool. You can do an overnight chlorine loss test to confirm this. Pool School - Perform the Overnight FC Loss Test (OCLT)

 

[Texas Splash]

Puertex, the CYA test can certainly be the trickiest. Here's a couple items that may help: Testing Cyanuric Acid with the TF-100 - YouTube

Proper lighting is important for the CYA test. You want to test for CYA outside on a sunny day, but keep the skinny view tube in the shade. Taylor recommends standing in the sun with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.

While several factors determine a reasonable FC loss for each pool, a 2.6 FC loss is not unheard of. In very "general" terms, if we are in the 2-4 ppm FC loss range, we're doing pretty good. I'm usually right around 2 - 2.5 depending upon activity in the pool. As Isaac-1 said though, whenever in doubt, run an OCLT. That's what I do too. And Pooldv has a good point about our TX sun. I actually crank my CYA a bit higher each summer. The sun is brutal where I live.

 

[kimkats]

I found just glancing into the tube and away, back and forth, until I cannot see the dot at a glance works best for me. Other wise I drive myself batty! I can see the dot if I stare long enough.

Kim