My CYA is high. I know I need to drain my pool but in the meantime is there a CYA test that will give a reading over 100. The Taylor and Blue Devil test kits only go to 100. My pool store says it 140 by their test but I don’t want to keep going to the pool store. I take it I can’t just dilute the sample by half as it looks like the scale is not linear.
High Level CYA Test
- Thread starter mikewen2
- Start date
- Jun 22, 2014
- 49,396
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Here you go:
If your CYA level is 90 or higher, repeat the test adjusting the procedure as follows:
1. Fill the mixing bottle to the lower mark with pool water.
2. Continue filling the mixing bottle to the upper mark 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.
5. Continue the test normally from step 2, but multiply the final result by two.
In other words, you are diluting the pool water, performing the test, then multiplying the result by 2.
If your CYA level is 90 or higher, repeat the test adjusting the procedure as follows:
1. Fill the mixing bottle to the lower mark with pool water.
2. Continue filling the mixing bottle to the upper mark 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.
5. Continue the test normally from step 2, but multiply the final result by two.
In other words, you are diluting the pool water, performing the test, then multiplying the result by 2.
Thanks. So I take it the results are linear if the CYA is above 90. Thanks again!
Really, because you don't want to drain any lower than 1 foot above the floor of the shallow end (to prevent the liner from shifting) it's only vital to know you're well above 100. You'll be draining less than half the water so there's no way you're going to overshoot, so no harm in performing the drain and refill, allowing adequate time for the water to circulate, and then testing again.
As to your question, the scale is not linear but the dilution is. If you halve the CYA in the sample then you will be able to double the result to get your actual CYA.
As to your question, the scale is not linear but the dilution is. If you halve the CYA in the sample then you will be able to double the result to get your actual CYA.
Thanks. I would be pretty nervous about draining my vinyl liner pool even that far. I just plan on draining it down to the bottom of the skimmer refilling and draining again a bunch of times until I get to the level I want.