CYA Test Accuracy

[isergy]

Does anybody know a better way to measure CYA besides the disappearing black dot test? I feel like I can never be certain when the dot has "disappeared."

Anybody have tips on getting an accurate measurement or know of a better method/kit or test strip?

I'm currently using the following kit:

Amazon.com : Pentair R151226 79 Cyanuric Acid Test Kit : Swimming Pool Liquid Test Kits : Garden & Outdoor

Amazon.com : Pentair R151226 79 Cyanuric Acid Test Kit : Swimming Pool Liquid Test Kits : Garden & Outdoor

www.amazon.com

Thanks in advance!

 

[ajw22]

There is no need for more accurate CYA testing of pool water. +/-10 ppm is adequate to determine your FC level and the dot test gives you that.

Don’t obsess over the test. Round up to the higher line after the dot disappears.

 

[usedtobeayooper]

Does anybody know a better way to measure CYA besides the disappearing black dot test? I feel like I can never be certain when the dot has "disappeared."

Anybody have tips on getting an accurate measurement or know of a better method/kit or test strip?

I'm currently using the following kit:

Amazon.com : Pentair R151226 79 Cyanuric Acid Test Kit : Swimming Pool Liquid Test Kits : Garden & Outdoor

Amazon.com : Pentair R151226 79 Cyanuric Acid Test Kit : Swimming Pool Liquid Test Kits : Garden & Outdoor

www.amazon.com

Thanks in advance!

As a newbie to this, invest in plenty of R-0013, do every test a hundred times, (not literaly, but initially a bunch), write it down, and pay attention to different lighting. I hate that test. Neferiosly uncertain. But I've come to believe that repeatability is the best answer.... it's not exact (which kills me), but I have found that after writing it all down, testing 8 million times, replicating the lighting each time, it's not as variable as it seems.

 

[Donldson]

If there were a better method at a reasonable price, don't you think we would use it?

The melamine test isn't all that great, but it is accurate if not precise. The issue is that you are trying to find exactly where the dot disappears. Don't. You're going to round it up anyway so it doesn't matter exactly where it disappears. Don't fret over this test. And don't use test strips unless you want even less precision and infinitely less accuracy. I have never seen the melamine test show 50 ppm on a fresh fill (0 CYA), but I have seen strips say that.

 

[ajw22]

If you error on the dot test you are likely to error on the high side by saying the dot disappears before it did. The result of that would be using a bit higher FC level for your targets. No problem with a bit higher FC level. So don’t sweat the test.

 

[AUSpool]

There is no need for more accurate CYA testing of pool water. +/-10 ppm is adequate to determine your FC level and the dot test gives you that.

Don’t obsess over the test. Round up to the higher line after the dot disappears.

I gotten this wrong in the past so please check me, round up to the higher 10ppm value, which would be the lower line after the dot disappears.

Issergy,
my advise is the same, don’t stress over it. With a concrete / pebble pool and a SWG I stay in the 60 - 70ppm range. My CYA slowly drops over time, when it gets close to 60ppm I add enough to get it back to 70ppm and I keep my FC set as if I have 70ppm CYA all the time (5ppm FC). To be entirely honest I stay at 5 - 6ppm FC.

You can use the ‘fill to the line’ method - my favourite. Fill to the 70ppm line, look, if the dot’s still visible fill to the 60ppm line. If its still visible, fill to the 50ppm line. If its now disappeared at the 50ppm line your CYA is 60ppm. - Done -don’t second guess just move on to the next test or adjust your CYA. I too hate the lack of accuracy but Its the best we have.

 

[frogabog]

Maybe these will help:

 

[isergy]

Thank you all so much. Think I’ve got it down. After testing a bunch today I think the Pentair kit is the answer. Let’s me test repeatedly without having to remove or add additional liquid. Just keep sliding up and back down. ??