CYA Standard Test Pics - Which is the result?

[Self Evident]

The following image contains two columns/series of pics taken of CYA tests. One series is a test of the 50ppm CYA Standard (R-7065) provided with the TF-100 test kit. The other series is a test of my pool water. I know which is which is which (I have a legend).

what I would like to do is compare interpretations/readings. In other words, in each column, which pic represents the "take this value" point?

(Each column is labeled from the top: L1, L2,... L7 for the left side; and R1,...etc for the right.)

For reference, here is a link to Taylor's CYA instructions with a few images of their test and what they indicate is a "reading": Taylor CYA Test.

I'll post the "answer" a little later (which column is the 50ppm Standard, and which pic contains the view tube filled to the "50" ppm line).

And, in the spirit of the Olympics, the first "winner" gets a gold colored looking smiley.
(sorry, no silver or bronze...)




Note: These pics were taken indoors, but near a large sliding glass door with plenty of light. However, it's not quite as much light shining thru the view tube as would be outdoors.


ETA: See post #29 for another series of pics comparing sun -vs- shade -vs- inside.

 

[Kiss4aFrog]

Ok, I'm game. I'll take L2 and R3

 

[TexasHeatWave]

I'll take L3 R3 for $500 Kiss4afrog......

 

[26venus]

My money is on L2/R2

 

[max2k]

L1 & R2 - the first ones where dot disappears.

 

[nlindelldc]

So I'm not sure that I fully understand. If one of them is the known 50 sample, and the other one is a pool with 50ppm, then in theory they should look the same.

My guess would then be L1 and R1.

And I would also suggest this renders the test inaccurate because you weren't outside in full sun with your back to the sun and the vial in the shadow of your body with vial at waist level.

 

[Self Evident]

So I'm not sure that I fully understand. If one of them is the known 50 sample, and the other one is a pool with 50ppm, then in theory they should look the same.

Ok, a minor clarification - I don't know what my pool CYA level is, hence the test.

So, both columns contain pics from the same fill points in the view tube, and one of those points is at the 50 ppm line. One column is of the standard, and one is of my pool water. However, I thought it would be interesting to ask for extra opinions on which reading seems the "most correct". And by not revealing which column contains the standard, the question can also check the quality of the overal test method. Maybe...

 

[nlindelldc]

Ok, a minor clarification - I don't know what my pool CYA level is, hence the test.

So, both columns contain pics from the same fill points in the view tube, and one of those points is at the 50 ppm line. One column is of the standard, and one is of my pool water. However, I thought it would be interesting to ask for extra opinions on which reading seems the "most correct". And by not revealing which column contains the standard, the question can also check the quality of the overal test method. Maybe...

Ahh, I gotcha.

I always have trouble with the CYA test it seems so my answer is probably not right

 

[max2k]

Ok, a minor clarification - I don't know what my pool CYA level is, hence the test.

So, both columns contain pics from the same fill points in the view tube, and one of those points is at the 50 ppm line. One column is of the standard, and one is of my pool water. However, I thought it would be interesting to ask for extra opinions on which reading seems the "most correct". And by not revealing which column contains the standard, the question can also check the quality of the overal test method. Maybe...

not all is lost- if you have known quantity or set of calibrated known quantities all you need is some sort of difference detector to place unknown quantity between 2 known ones. The difference detector doesn't have to be very accurate or linear- as long as it can detect the difference and its sign you're good.

Your pool water sample looks close to 50 ppm 'known quantity' so you could extrapolate up or down to get your value. Of course I'd prefer drop counting color changing test any day.

 

[Holydoc]

My money is on L2/R2

Agree.

 

[Dz7]

I see the dots all the way to L1,R1...obscured but clearly there below those points.

 

[Self Evident]

Re: CYA Standard Test Pics - Which is the result? Survey Says....!

Drum roll please...

The Left series of pics if of the CYA 50ppm standard; the Right is of water from my pool (both with CYA reagent, of course).

And the order of the pics is as follows:

# | ppm line
--+--------
1 | 25
2 | 30
3 | 35
4 | 40
5 | 50
6 | 60
7 | 80
|empty

(Yes, I know there's no "25" or "35" line on the CYA view tube, in those pics it was filled to those approximate levels, logarithmically.)

So, L5 is a pic of the view tube filled to the 50ppm line, with the CYA 50ppm standard.

At least I now know it's not just me.

In practice I was taking the CYA reading for my pool to be 30 or 35 (L2 or L3). But now it seems it may be closer to 50. This comparison makes me question my prior readings. But, it also makes my question either the standard, or the instructions on how to read the test. To be fair, the pictures do show the black dot just a tad more evident than when read in practice. That is, pic L5 looks like L4 in practice, etc., but that's not enough to change the reading from 30 to 50...

I'm going to do another CYA test of my pool & the standard tomorrow to see if results are repeatable. Stay tuned for the exciting results!

Until then, has anyone else tested the standard in their kit to see if it actually produces a reading of 50 (black dot not visible at the 50 line)?

In anycase, thanks for playing along with this episode of "The View Tube Feud"!
Or maybe it should be called, "View Tube of Fortune!"
Or, "The Reading is Right!".
Or...

 

[PAGirl]

I've often see them recommend more of a "glance" than at "stare" when looking for the dot.

 

[JoyfulNoise]

You may want to repeat your test using the #9056 (2000 Series) comparator block from Taylor. It is designed differently that the round tube as it has a frosted plastic side. I would also strongly suggest you repeat your test outdoors, the CYA test is not meant to be done with indoor lighting.

Independent tests by TFP'ers have shown that they get a read of the 50ppm CYA standard much closer to that mark on #9056 comparator block than they do using the round view tube.

 

[max2k]

Re: CYA Standard Test Pics - Which is the result? Survey Says....!

Drum roll please...

The Left series of pics if of the CYA 50ppm standard; the Right is of water from my pool (both with CYA reagent, of course).

And the order of the pics is as follows:

# | ppm line
--+--------
1 | 25
2 | 30
3 | 35
4 | 40
5 | 50
6 | 60
7 | 80
|empty

(Yes, I know there's no "25" or "35" line on the CYA view tube, in those pics it was filled to those approximate levels, logarithmically.)

So, L5 is a pic of the view tube filled to the 50ppm line, with the CYA 50ppm standard.

At least I now know it's not just me.

In practice I was taking the CYA reading for my pool to be 30 or 35 (L2 or L3). But now it seems it may be closer to 50. This comparison makes me question my prior readings. But, it also makes my question either the standard, or the instructions on how to read the test. To be fair, the pictures do show the black dot just a tad more evident than when read in practice. That is, pic L5 looks like L4 in practice, etc., but that's not enough to change the reading from 30 to 50...

I'm going to do another CYA test of my pool & the standard tomorrow to see if results are repeatable. Stay tuned for the exciting results!

Until then, has anyone else tested the standard in their kit to see if it actually produces a reading of 50 (black dot not visible at the 50 line)?

In anycase, thanks for playing along with this episode of "The View Tube Feud"!
Or maybe it should be called, "View Tube of Fortune!"
Or, "The Reading is Right!".
Or...




good point- meaning members often misread their CYA lower by at least 20 ppm. This needs more data IMO under different lighting conditions. This test is too subjective and unfortunately it's the basis for everything else.

 

[oldguy70]

Re: CYA Standard Test Pics - Which is the result? Survey Says....!

I have the Standard 50...outside bright sun to my back, tube in shade, I get a close 50 (using the Taylor #9193 test tube)

If I turn the tube towards the sun, I can get reading as low as 30.

 

[JamesW]

The bottom set of pictures reminds me of this quote:

“And if you gaze long enough into an abyss, the abyss will gaze back into you.”

 

[JamieP]

This is a very interesting thread. You revealed your answer before I was able to record my guess (I just finished reading through from the beginning and had decided my guess before I got to your reveal), but since only yesterday I had done something similar with the standard CYA solution compared to my pool water, I had in my mind what 50 looked like for me with the sun to my back and the view tube in my shadow. It looked just like your L5! The hard part is that is nowhere near what I would have considered constituting having the black dot gone. Even in the shade the dot was still very visible. It was at 40 when I would have considered it closer to actually "disappeared." It makes me dread doing the CYA test! Thinking the CYA is lower than it actually is would cause someone to add more CYA than they needed, possibly throwing off their target FC range. This is especially troubling during a SLAM, and even more so when you keep your CYA at 80 to manage a SWG in a southern climate like I do.

It sounds like I need to invest in the #9056 comparator block. Hopefully that will help.

 

[nlindelldc]

This is a very interesting thread. You revealed your answer before I was able to record my guess (I just finished reading through from the beginning and had decided my guess before I got to your reveal), but since only yesterday I had done something similar with the standard CYA solution compared to my pool water, I had in my mind what 50 looked like for me with the sun to my back and the view tube in my shadow. It looked just like your L5! The hard part is that is nowhere near what I would have considered constituting having the black dot gone. Even in the shade the dot was still very visible. It was at 40 when I would have considered it closer to actually "disappeared." It makes me dread doing the CYA test! Thinking the CYA is lower than it actually is would cause someone to add more CYA than they needed, possibly throwing off their target FC range. This is especially troubling during a SLAM, and even more so when you keep your CYA at 80 to manage a SWG in a southern climate like I do.

It sounds like I need to invest in the #9056 comparator block. Hopefully that will help.

This is me exactly to the letter. I bought the known 50 to make sure I was guesstimating the CYA correctly and, as it turns out, I was reading my CYA low, thus adding too much thus not keeping my FC high enough. I've had 2 algae blooms because of it (at least that's my theory). i will be ordering the 9056 also

 

[Scoop]

I bought the Taylor 9056 and have been using it for my pH & CYA tests for a while. It's a little easier for me to read the CYA test with this vial vs the Taylor 9193 tube.

When I use the TFP 50 CYA solution, I usually read about 50-60.