CYA testing

Blake106

In The Industry
Jan 8, 2020
17
Hawaii
I have a pentair cya test kit (R151226 79) and getting quite a significant difference between different reagent bottles. I was using one that was almost empty and got a result of 120ppm. Tested in exact same lighting conditions. Used a bottle that’s never been opened and got 60ppm. There are no expiration dates for these so I’m not really sure what the deal is. Got both reagents no more than a few months ago. Could one just be a dud? Not sure what is actually correct. I can’t be having variations like that since this is a commercial pool. Any more accurate testing for CYA out there? Thanks.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
33,384
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
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Pentair Intellichlor IC-60
How did you read 120 ppm? The Pentair test only has a 100 ppm line as its maximum and then a 60 ppm line before it?
 

Blake106

In The Industry
Jan 8, 2020
17
Hawaii
50% pool water and 50% distilled water for the “A” line. There’s a faint white extrusion between line A and the bottom of the test tube for a 50/50 dilution test, well at least it looks like it’s there for that exact purpose. Doesn’t say in instructions.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
33,384
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
50% pool water and 50% distilled water for the “A” line. There’s a faint white extrusion between line A and the bottom of the test tube for a 50/50 dilution test, well at least it looks like it’s there for that exact purpose. Doesn’t say in instructions.

When you dilute the sample by 50% you double the error. The CYA test starts with a wide variability. I would take the 120 reading as inaccurate but telling you it is not far above 100.

So between the two reagents your CYA is between 60-100.

What is the CYA range you are allowed in your commercial pool?
 

Blake106

In The Industry
Jan 8, 2020
17
Hawaii
When you dilute the sample by 50% you double the error. The CYA test starts with a wide variability. I would take the 120 reading as inaccurate but telling you it is not far above 100.

So between the two reagents your CYA is between 60-100.

What is the CYA range you are allowed in your commercial pool?
Where I am in Hawaii there doesn’t seem to be any enforcements of CYA and cannot find anything on the internet about it, as long as the FC is at least 0.6ppm and PH is between 7.2 and 7.8 it’s good to go for the inspection. I follow the the average mainland enforcements for a public pool because it makes me feel more comfortable, so for me 20-100ppm CYA and follow the fc to cya ratio. Would prefer to keep cya at 30 but it’s challenging because we have trichlor tab chlorinators and manual dosing of liquid chlorine or cal hypo just barely makes it through the day.
 
Last edited:

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
33,384
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
With your CYA you need to keep the FC in the 8-12 ppm range.

I would plan for a 50% drain of the pool soemtime soon to bring the CYA down before it gets too high.

 
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Blake106

In The Industry
Jan 8, 2020
17
Hawaii
Taylor’s cya test tube #4088 for kit L-0206 and pentair’s test tube appear to be identical, can I use Taylor’s r-0013 reagent in a larger quantity bottle for the pentair kit I currently have?
 

Mdragger88

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Jun 1, 2018
4,310
Hernando, Ms
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Vinyl
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Intex Krystal Clear
The regeant is the same i believe-
I have used blue devil cya regeant (which is rebranded pentair regeant) in place if r0013 with similar results due to availability issues.
The amount of regeant & pool water you use for those slider tubes is higher than with the Taylor 9193 tube or the tf100 cya tube so you will go through reagent faster. The latter use a separate mixing bottle then you pour it into the view tube. They can both be had for less than $10 if u wish to change your method .
 
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