Hello and CYA @ 240-300

[han78216]

I took some water to local pool store for testing. Somehow, they came out with CYA=70.

Not sure what that means... I'm going to retest today.
If it's really 70 then I should be able to test without diluting the water first.

[PoolDoc]

It means -- if it's accurate -- that you have enough CYA in your pool without adding more. One way to check is dose with chlorine in the evening, wait, test, and then retest in the AM. If the chlorine doesn't drop much, then you don't have any unusual chlorine demand. Wait again till the following evening, and test again: if it doesn't drop more than 1/3 - 1/2 during a sunny day . . . you have a fair bit of CYA in the pool.

[aylad]

If it's any help, I am in Northwest Louisiana and my pool gets full sun from sunup to sundown and has a pretty heavy bather load from mid April through beginning of Sept--we also have a very warm, humid climate (today's high is 96 degrees, so far)....I keep my CYA at 80-90, and my chlorine in the 8-12 range. No ill effects on the kids, no faded suits or liners, no skin or eye irritation reported.

Janet

[han78216]

My original testing (240-300ppm) and retest after partial drain (160ppm) was done by mixing 3 cups of tab water and 1 cup of pool water. I then multiplied 4 to the reading.

I'm not sure how my testing of 160 is so far from pool store's 70 reading unless diluting water is messing up the reading or pool store's testing is way off.

[PoolDoc]

The tap water is not the problem -- there's no CYA used in potable water treatment. But, there are a variety of ways for CYA tests to be inaccurate -- it's by far the most subjective of the tests in the K2006, and is a good test ONLY in the sense of being better than 'guess-strips', and in being 'good enough', but only barely!

[han78216]

I tested water with K2006 yesterday and it was clearly over 100.
I guess this tells you can't really trust test results from the pool store.

[aylad]

I guess this tells you can't really trust test results from the pool store.

That's why we push for people to learn to test their own water. Pool store test results are designed to sell chemicals..