What's the most accurate CYA test?

[PatL34]

The method I outline in this thread below should help you to be consistent in your CYA testing. Because the test is so subjective it may be tedious to some people, but if you want reliability in your testing you have to be consistent.

Accuracy of the CYA test will always be debatable, but until you are consistent with the way you test, this will be the closest to accuracy that you can get.

Pat

http://www.poolforum.com/pf2/showthread.php?t=1855

[dafletcha]

Thanks, Pat. There's some very helpful information on that thread.

[tenax]

does anyone else have the plastic type tube with the dot in it? i thought that is what everyone has..it's called a taylor C.A. view tube and the range is from 20 to 100. it's what i was given when i bought my pint of test re-agent this summer. seems to work quite well

[chem geek]

dafletcha,

Don't forget that part of the reason for having higher CYA with higher chlorine levels is to have enough in "reserve" so you don't go below the minimums at any time during the day. If your pool is exposed to sunlight, then it may lose around half of it's total chlorine in a day assuming you have at least 30 ppm of CYA (it will lose even more with less CYA). If you have a pool cover, then you can probably have low CYA and low chlorine levels, but without a cover and with exposure to sunlight, you might not be able to do it.

See what your chlorine loss is during the day and specifically between the times you pour more chlorine into your pool. If you think you can keep a minimum level, then fine, but if not, then it's better to play it safe with higher CYA and higher chlorine. That's why Ben's chart doesn't "roll off" to very low FC at low CYA because it's really hard to maintain very low FC in outdoor pools exposed to sunlight.

Richard