How long do Standard Solutions remain effective? (regarding R-7065 CYA 50ppm Solution Shelf Life)

duraleigh

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In The Industry
Apr 1, 2007
34,363
Sebring, Florida
The R-0013 (correct number) That comes from TFTestkits is supplied by Taylor........they are totally identical. You may have even been using the same batch number.

The view tube from TFTestkits is used because it uses a sample volume double that of the Taylor view tube and it was felt should give a somewhat more precise test result....there is no conclusive evidence to support that over the years but it (TFTestkits view tube) is a bit easier to read.

Y'all are wa-a-a-y overthinking the issue. The CYA test using R-0013 has always been the least precise of all the tests so it allows your personal interpretation to come into play. The bottom line is the Taylor R-0013 and the TFTestkits R-0013 comes from the same "bottle" and is unaltered by either company in any way.
 
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Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,904
Central California
TishTash, thanks for that very thorough experiment and right up. It's bad enough that the CYA test sucks as bad as it does, considering how important a good result is to proper pool water care. Apparently the standard sucks, too. I hope Taylor and TFTestKits can get to the bottom of this unfortunate situation. Did you share your results with both of them?
 
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pb4uswim

Well-known member
Jul 23, 2020
72
Michigan
I know this is heresy, but I rely on the pool store for my CYA reading. I still do the dot test and I actually come reasonably close to the pool store. I also am a new pool owner so I know how much CYA I’ve actually put in the pool. Thankfully, all three data points are consistent. Again, I know this is frowned upon, but if I had readings when I did the dot test that were as far off as described in this thread, I’d rely on the pool store to get me back on track. I’m lucky enough to have two stores near me so I might even see if, between them, they would come up with a similar, to each other, reading.

I wonder if there’s a digital test (meter) available and how much that would cost. Or, is there an independent lab that a sample could be sent to that is trustworthy. At some point, us folks with OCD, need to have a number we can rely on.
 

Dirk

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TFP Guide
Nov 12, 2017
6,904
Central California
I know this is heresy, but I rely on the pool store for my CYA reading. I still do the dot test and I actually come reasonably close to the pool store. I also am a new pool owner so I know how much CYA I’ve actually put in the pool. Thankfully, all three data points are consistent. Again, I know this is frowned upon, but if I had readings when I did the dot test that were as far off as described in this thread, I’d rely on the pool store to get me back on track. I’m lucky enough to have two stores near me so I might even see if, between them, they would come up with a similar, to each other, reading.
So it's good that you know it's heresy, but I'm not sure you understand why. Trust your own test result. Even if it's not exactly right, if you do the test carefully, and the same way each time, then you will get repeatable results. Which is way more important than getting the number exactly right. When you go to the pool store, or worse, multiple pool stores, the tests are being done by a random member of however many employees staff the store. So those results are not repeatable, and so completely unreliable.

Even if your CYA number is off by 10, if only you are doing the testing (carefully) it will always be off by 10. And when you apply that result to dosing CYA, your dosing will be consistent. If you at some point find your FC not holding as it should (and have ruled out other factors that can cause that, also by doing your own testing), then you know you need to add a bit more CYA. Which will then be the norm for your pool, which you can recreate with your testing.

If you side with pool store numbers over your own, they will sometimes be dead on, other times be over by 10, other times be under by 20, etc, and you'll never get to the point where you can confidently dose the correct amount of CYA each time.

Trust your CYA number. Don't go after any others. Your pool will be better off in the long run...
 

Bperry

Gold Supporter
Aug 20, 2020
71
Knoxville, TN
For what it’s worth, I accidentally bought two larger bottles of the CYA 50 standard from Taylor and using the 2006 kit, the dot “disappears“ at 50. But I have to really strain to see whether the dot is there or not as it sort of looks like it’s there and sort of not. So I’ve determined that when I do the test, I make sure I have to do the same amount of straining to figure out if the dot is really visible, then I know it’s the right time to read the value it’s at.
 
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DanF

Silver Supporter
Mar 17, 2019
265
Chandler, AZ
Sounds like what I will try, @Bperry. When you did the test with the standard solution, did you use the smaller tube attached to the comparator, or the larger CYA view tube? And did you use 7ml each of the standard solution and the R-0013?
 

Pauls234

LifeTime Supporter
Jul 4, 2012
475
Chicago, IL
I'll throw in my experience to this worthy discussion.....

The standard solution looks like 40 to me when I do the outdoors, afternoon, back to the sun, but Taylor is telling me this is what 50 looks like so I believe them.

Interestingly, when I do the test indoors with the standard solution it does looks like 50, so now I just do the test indoors and go with that.
 
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Bperry

Gold Supporter
Aug 20, 2020
71
Knoxville, TN
Sounds like what I will try, @Bperry. When you did the test with the standard solution, did you use the smaller tube attached to the comparator, or the larger CYA view tube? And did you use 7ml each of the standard solution and the R-0013?
In my kit, the CYA tube is the smaller of the two. I use 7ml of the standard and 7ml of the reagent.
 

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