Another CYA question

[keagle]

How do I know if I'm testing the CYA correctly? Does the black dot have to totally disappear? Do you kind of see it (because you know it's there)? If I hold the tester tube over something white it seems to disappear with less water/R-0013 then if non white service is below tube, etc. I use the T-100 test kit.

(We had to do a slam at the end of June. Followed TFP advice. Pool is crystal clear now.)

 

[Texas Splash]

Yes, the black dot should completely disappear. It may help to look briefly down the tube then look away, then back to re-focus. Staring at the dot can make you nuts.

Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently 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.

 

[keagle]

Thanks. I will go outside for my next test. When I pour the mixed solution from the skinny view tube back to the mixing bottle to repeat the test, should I empty the remaining solution in the mixing bottle first, or just add the mixed solution?

 

[AftonJeeper]

No need to empty the mixing bottle.

 

[keagle]

Thank you!

 

[TomGallopavo]

I do it in the morning Sun, back towards it. Fill to 100 then look at the tube waist level. If I see the dot I fill to 90 and repeat...so on until I don't see the dot. Your supposed to round up anyway so why not fill to the lines.

 

[Demegrad9]

I do it in the morning Sun, back towards it. Fill to 100 then look at the tube waist level. If I see the dot I fill to 90 and repeat...so on until I don't see the dot. Your supposed to round up anyway so why not fill to the lines.

I'll have to try this. I usually just add one drop at a time and drive myself nuts because I always feel like it needs "just one more drop". Maybe by filling to the next line and just taking a quick glance down the tube I'll get a better result. I'm pretty sure if you stare down that tube long enough knowing there's a dot down there that your brain will eventually tell you that you see a dot.