Unexpected CYA test result

[ajw22]

Does CYA naturally rise when undisturbed for a period of time?

Water stratifies when undisturbed and the chemicals separate in the different levels depending on their weight.

So depending on the level you took the sample you could get more or less CYA then when it is well mixed and equally distributed on the pool.

 

[Sws]

Since no one answered it directly, CYA does not naturally increase over time.

Thanks. I should have clarified that.

I wasnt asking if it increases, I was asking if it could physically rise to the surface.

 

[Donldson]

I wasnt asking if it increases, I was asking if it could physically rise to the surface.

No. If the water stratified it would leave fresh water at the surface and show low or no CYA.

 

[Newdude]

When you have the test kit, you're free to use the digital tester as long as it throws reasonable results. With frequent testing and some experience, you'll pretty much know what to expect each time.

But if it throws *1* wonky result, you go back to ole reliable until it's behaving again.

 

[Sws]

When you have the test kit, you're free to use the digital tester as long as it throws reasonable results. With frequent testing and some experience, you'll pretty much know what to expect each time.

But if it throws *1* wonky result, you go back to ole reliable until it's behaving again.

Thanks. I have a good feel for what the pool does and how it reacts to changes with the digital tester which is why I was so surprised yesterday.

FWIW, I let a pool water sample sit inside over night and tested it at room temperature (about 66) CYA was at 48 which is closer to where I expected it to be.

I also warmed the sample by placing the jar in a cup of warm water to get it into high 70s. CYA reading dropped to 42. My initial expectation was around 40 which is why the 94 was a shock. I think this validates the temperature skew.

I couldn't run the pump because the filter started to leak at the seam. Ill address that today and get the filter running.

Im really looking forward to trying the Taylor kit too.

This is what I decided to get based on the link you posted.

1 - TF-Pro Salt @ $270.50
Optional Items (see below for details): C-600 pH + Salt Meter
Optional Items (see below for details): pH Tester
Optional Items (see below for details): Salt Test Strips
Optional Items (see below for details): SLAM Option
Optional Items (see below for details): Standard Sampler

 

[ajw22]

You do not need the Salt Test Strips. The TF-Pro Salt includes a salt test.

I use this eSeasonGear Salt-3000 meter…

https://www.amazon.com/eSeasonGear-SALT-3000-Digital-Salinity-Temperature/dp/B019E82RPO

 

[Newdude]

FWIW, I let a pool water sample sit inside over night and tested it. CYA was at 48 which is closer to where I expected it to be.

Typically with the Taylor test, cold water reads low with less turbidity. But all bets are off with a digital reader of a test strip.

At least you'll have a fall back option when things get wonky going forward. Of course, Murphys says the handheld will be dead on forever once you have another way.

 

[Sws]

Typically with the Taylor test, cold water reads low with less turbidity. But all bets are off with a digital reader of a test strip.

At least you'll have a fall back option when things get wonky going forward. Of course, Murphys says the handheld will be dead on forever once you have another way.

That's fine with me as long as it's right. Also, I think everyone is thinking that the photomoter is reading the strip. Its not.

The strip dispenses the reagent into the water sample and the photomoter reads the reaction of the reagent in the water.

The Taylor test shipped already. It shouldn't be long before its here.

 

[Sws]

I did some limited testing with what I have. Here is what I found. Take it for what its worth until I get the TF kit to compare. Part is copied from a previous post but I want to keep the comparisons together.


I let a pool water sample sit inside over night and tested it at room temperature (about 66) CYA was at 48 which is closer to where I expected it to be.


I also warmed the sample by placing the jar in a cup of warm water to get it into high 70s. CYA reading dropped to 42. My initial expectation was around 40 which is why the 94 was a shock.

I let the pump run for 12 hours and found the following:
Cold sample 93ppm.
Warm sample 43ppm.

It appears that temperature is the biggest factor for the change. Circulation barely changed anything.

Ill do it all over again once the TF kit comes and post again. Hopefully someone finds it useful.

 

[Sws]

I was able to play with the TF kit tonight with Taylor reagents.

Results are as follows with Sensafe on the left and TF on the right. Its my first time using the TF so there may be human error here, but I did repeat some tests with the TF kit and the numbers didnt change. Updated with a Leslies test on the right.

Alk 100 70 59
Calcium 110 225 137
FC 6.6 9.5 7.0
CC .3 0. 0
TC 6.9 9.5. 7.0
CYA 43 30/40ish 40


I need to do them over in sunlight. I need to look more into the CYA testing method to see what people describe as "fully obscure" i was able to see a shadow of the black dot for probably the whole test with a warm sample and a around 40 with a cold sample.

Overall, I'm disappointed in the Sensafe numbers with Taylor reagents being the "gold standard", unless I just need to identify something I did wrong. I also wish the dot disappearing was more dramatic, but maybe its because my CYA was lower than I had thought...or it could be my kitchen light. Time will tell.

 

[PoolStored]

TF kit and the numbers didnt change.

I know...right?

I need to look more into the CYA testing method to see what people describe as "fully obscure"

Print these out. Read them a couple times. You'll get it:

CYA - Cyanuric Acid Test

Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…

www.troublefreepool.com

You can also get a standard sample that has 50 CYA..so you KNOW what it looks like...

R-7065 CYA Standard 50ppm (2oz)

tftestkits.net

 

[PoolStored]

Overall, I'm disappointed in the Sensafe numbers with Taylor reagents being the "gold standard", unless I just need to identify something I did wrong. I also wish the dot disappearing was more dramatic, but maybe its because my CYA was lower than I had thought...or it could be my kitchen light. Time will tell.

The L1 ANSI standard is just not up to the Taylor accuracy. It's not you it is the chemistry and the technology. Trust the Taylor reagents. They are the "gold standard."

I just updated the CYA testing article last fall. CYA test is turbidity test and highly dependent on light. Read the CYA testing article, it will help you.

I conversed with Taylor, over a period of time, to understand. You need to use indirect lighting to see the turbidity. You need strong indirect lighting, with the sun to your back, vial in the shadow of your body. Very roughly speaking, direct overhead sunlight is around 100,000 lux, strong indirect light (i.e. shaded from the sun) is around 10,000 lux, an overcast sky is around 1000-5000 lux but varies on how overcast (which is why a bright white cloud overcast is still OK), indoors is usually < 1000 even in a bright kitchen (more typically 500 lux). Sunlight, even on an overcast day, will provide more accurate results than indoor lighting. See the article for obscured, or order the 50ppm standard (that is how I learned).

 

[Sws]

The L1 ANSI standard is just not up to the Taylor accuracy. It's not you it is the chemistry and the technology. Trust the Taylor reagents. They are the "gold standard."

I just updated the CYA testing article last fall. CYA test is turbidity test and highly dependent on light. Read the CYA testing article, it will help you.

I conversed with Taylor, over a period of time, to understand. You need to use indirect lighting to see the turbidity. You need strong indirect lighting, with the sun to your back, vial in the shadow of your body. Very roughly speaking, direct overhead sunlight is around 100,000 lux, strong indirect light (i.e. shaded from the sun) is around 10,000 lux, an overcast sky is around 1000-5000 lux but varies on how overcast (which is why a bright white cloud overcast is still OK), indoors is usually < 1000 even in a bright kitchen (more typically 500 lux). Sunlight, even on an overcast day, will provide more accurate results than indoor lighting. See the article for obscured, or order the 50ppm standard (that is how I learned).

Thank you,

I was just reading that. Ill try outside in the daylight tomorrow. Im also going to buy the 50ppm sample for a solid comparison.

I appreciate the support.

 

[PoolStored]

If you have found value, TFP is a 503c non-profit. We are all volunteers...you might consider becoming a supporter to keep the lights on...

Become a TFP Supporter

Help Support TFP Trouble Free Pool is run by a dedicated group of volunteers that … Read more…

www.troublefreepool.com

 

[PoolStored]

As I reflect on this thread. You and I are not much different. I was *PoolStored* for $1500 before I found TFP. I figured, I got a 5 on my AP Chem, I can figure this out....I questioned everything.

Two threads for you....my AHAs!!!

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...

www.troublefreepool.com

I knew I was Pool Stored when...

With the influx of springtime new members rolling in, oddly, I found myself astounded at the number of members that have been Pool Stored. I don't know why it struck me this year, after helping so many that have been pool stored in the past, and even having the username PoolStored, but...

www.troublefreepool.com

 

[Sws]

As I reflect on this thread. You and I are not much different. I was *PoolStored* for $1500 before I found TFP. I figured, I got a 5 on my AP Chem, I can figure this out....I questioned everything.

Two threads for you....my AHAs!!!

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...

www.troublefreepool.com

I knew I was Pool Stored when...

With the influx of springtime new members rolling in, oddly, I found myself astounded at the number of members that have been Pool Stored. I don't know why it struck me this year, after helping so many that have been pool stored in the past, and even having the username PoolStored, but...

www.troublefreepool.com

Question everything...story of my life. Lol

I need to see things for myself, even if it means spending hours messing with stuff. I probably did 10 tests just to see how temperature affects CYA readings.

Im done for tonight. Ill play more tomorrow. Thanks again.

 

[PoolStored]

Question everything...story of my life. Lol

I believe we live in a simulation...JK.

We are brothers/sisters of another mother.

Show me/tell me, let me see it for myself. I have been TFP red pilled. My pool and thousands others are proof. Link--How Clear is TFP Clear?

 

[DrewLG]

I need to look more into the CYA testing method to see what people describe as "fully obscure"

You bought the Standard Sampler, so you have a 50ppm CYA sample that you can use to calibrate your eye.

Wait for a sunny day, then perform the CYA test using that Standard instead of pool water:

1. Fill the CYA test bottle to the 7.5ml line with liquid from the CYA Standard.
2. Add CYA reagent to the 15ml line.
3. Mix for 30 seconds.
4. Wait 2 minutes.
5. Mix again, and fill the CYA test tube to the "100" line.
6. Standing with your back to the sun, hold the test tube at waist level and look down into it. What you see is not obscured enough.
7. Add more liquid, to the 90 line, and look again. That's still not obscured enough.
8. Add more to 80, 70, and 60. Look each time; those aren't obscured enough.
9. Add liquid to the 50 line. Look. What you see now is what you should look for when you do the test for real, with pool water.

 

[PoolStored]

hold the test tube at waist level and look down into it.

Hold the sample IN THE SHADOW OF YOUR BODY at waist level and look down into it...

 

[DrewLG]

Hold the sample IN THE SHADOW OF YOUR BODY at waist level and look down into it...

With your back to the sun, it's kinda hard to do it any other way...