Pool Store CYA Test

[CreedenceTapes]

Background

I acquired a new-to-me pool at the end of last season with CYA through the roof. (I refilled recently and that, of course, took care of that.)

But before being hip to the TFP ways, I took a sample to a local (independent, I think) pool store. To be clear, this was before the refill.

They ran the sample through some kind of device that required injecting the sample with a syringe. It reminded me a little of the process of injecting the GC/MS machines I used way back in college. They then printed out an analysis that gave, among other things, a CYA level around 150 or so. I then discovered TFP, read up on CYA, and got a Taylor test kit. All I could discern from the Taylor kit was that the CYA was well over 100.

Also for clarity: I understand the logic of distrusting pool store tests in general and have come to, in fact, distrust them.

Question

Given the low amount of practical information yielded by turbidity testing when CYA is so high, I have been wondering if, in this limited circumstance, that pool store's "analyzer" is providing more useful data than the turbidity test's result of just "way too high". Does anyone have any insight on how this analyzer might find the CYA value, and whether it might, under such condititions, be at all reliable?

 

[ajw22]

Pool store analyzers are never as reliable as your testing.

For CYA > 90ppm, repeat the test adjusting the procedure as follows:

1. Fill the mixing bottle to the lower mark (15 ml line) with pool water.
2. Continue filling the mixing bottle to the upper mark (30 ml line) with tap water.
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark (15 ml line).
5. Continue the test normally from adding R-0013, but multiply the final result by two.

If you need to dilute the pool water further then apply these ratios:[7]

Pool water	Tap or distilled water	Multiply result by
1	1	2
1	2	3
1	4	5

 

[CreedenceTapes]

Pool store analyzers are never as reliable as your testing.

For CYA > 90ppm, repeat the test adjusting the procedure as follows:

1. Fill the mixing bottle to the lower mark (15 ml line) with pool water.
2. Continue filling the mixing bottle to the upper mark (30 ml line) with tap water.
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark (15 ml line).
5. Continue the test normally from adding R-0013, but multiply the final result by two.

If you need to dilute the pool water further then apply these ratios:[7]

Pool water	Tap or distilled water	Multiply result by
1	1	2
1	2	3
1	4	5

This is extremely helpful. Thank you!