CYA level

[tony3138]

I have a 32K gal inground vinyl pool. 3 weeks ago I took a water sample to the local pool store for analysis. They said the CYA was 171 and that I needed to drain and refill 70% of the water. I am on a well system so that is not possible without having water hauled in. So, I set up a system to drain fresh rain water off my shingle roof into the pool. As of this week I have captured 10K gal of fresh rain water in the pool. Yesterday I took a sample of water to the pool store and was shocked to find that the CYA level is now 210. Does this make sense? With 10K gal of fresh rain water being put into the pool I would have expected at least a small drop in CYA. The pool is perfectly clear and appears algae free.

 

[ajw22]

That is why we recommend you have your own test kit and do your own testing. Pool Store testing is unreliable.

You need to get the Taylor K-2006C or TFT Test Kits

Your CYA is high and needs more dilution. Keep on capturing rain water into your pool.

When you get your Test Kit, you will need to do the CYA Dilution Test…

CYA > 90 dilution Test​

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:[8]

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

Note that when doing a diluted test not only do you multiply the range of the test you multiply the error rate of the test, so results are a ballpark - not an absolute.

See CYA Testing for tips in how to read the test results.