Wide ranging test results from 4 sources??

Alset2

Gold Supporter
Aug 16, 2019
50
Cent Fl
So, this morning at 8am I collected 3 sample bottles of water from same depth (about 18") and started on a trek to get 3 different ,independent, tests to see how they match with my testing for the last 2 weeks. I fully expected SOME variation but did not expect what I got and would welcome any input.
I will list the results below including mine at the same time I collected these sample. All tests were done with in 3 hours of collection .
I use 3 different test (yes I am crazy like this...I like data) I have a chl & ph drop kit(Clorox brand), a Lamotte Color pro 7 digital, and the test strips the pool builder gave me (this is a new pool and this is the 1st official tests done since SWG installed 2 weeks ago).
for the most part, all 3 test I have at home are pretty close . I do all of them at the same time. The most variance is always the alk and CYA but not more than 20%.

So with that said I will post the Lamotte results since they are expressed in numeric form.

{My Test: } { STORE A (MANUAL TEST) } { STORE B (MANUAL ) } { STORE C (DIGITAL TESTER)}
FC= ( 4.1 ) ( 5 ) ( 3 ) ( .34)
TC= (4.24 ) ( 5 (.02 DIFF) ) ( * ) (1.97)
PH= (8.1 ) (8) ( 7.8 ) ( 7.6)
ALK = ( 73) (200) (75) ( 60)
CH= ( 445) ( 460 ) (365 ) ( 370)
CYA= (69 ) ( 90) ( 45) ( 15)
SALT = (3670) (HAND HELD SLAT METER) (3000) (3300 ) ( none)

Store A & B are chains and store c is a local store that installs spas and above ground pools only if any of that matters .

I have not spent much time evaluating this but it appears that almost every test has an outlier result that makes no since. One of my questions is , which should i use for my monthly testing results for warranty stuff?
Another is ,for my sanity, which one should I use to add chemicals by? I am leaning towards my test since i know "I" care about it AND I followed proper procedure for each test.
I am more than happy to by the TFP test kit but truth is I have trouble with color distinction in my test kits at least.

Any input would be appreciated

Thanks
Neil
 
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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,446
Laughlin, NV
We will always select your own testing if done with a proper test kit.

The ColorQ is OK for low FC testing and some other parameters. Not accurate for CH testing.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,446
Laughlin, NV
Remember that a Taylor titration kit is looking for a color change, excluding the pH test match. So I would encourage you to get a TF100 or Taylor K2006C.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,633
Bedford, TX
Neil,

The only tests that we rely on are from either a TF-100 or a Taylor K-2006C...

That said, I have the ColorQ and it will work just fine for your routine tests.. The problem with any test system that uses the color of the water to determine a test number is that several things can interfere with the accuracy.. For the ColorQ, the test tubes need to be newish with no scratches and the inside of the test device, which has a light and a receiver must also be clean and not scratched.. The TF-100/K-2006 do not rely on the actual color of the sample, but rather when the color suddenly changes from one color to another.. The actual color is not all that important.

I use my ColorQ to give me a feel for any changes to the balance of my pool water.. as an example... I really don't care if my FC is 7 or 8 ppm... I'm just looking to see what my FC is today vs. the last time I tested. This test info lets me know if I need to increase or decrease the amount of FC in my pool.. In most cases this is all the accuracy that I need.. When I need to know for sure exactly what my FC is, I'll use my TF-100.

If you are managing your pool on the edge of any tolerance, then you are just making things much harder than they need to be.

To Marty's point about the ColorQ, and to what they call the Calcium Hardness (CH) test... No matter what LaMotte calls it in their paperwork, they actually measure Total Hardness and not Calcium Hardness. Total Hardness depends on a lot of other hardness factors other than just Calcium. Total Hardness depends a lot on your local water.. I use my TF-100 to get an accurate reading on CH measurement and then from the same sample, use the ColorQ to measure hardness. I then use the difference to adjust what the ColorQ says is the CH to what the actual CH should be... Again, I am not looking for absolute accuracy.. So, if my TF-100 says my CH is 300 and my ColorQ says 350, then when I use the ColorQ to test CH, I always subtract 50 ppm. I only test my actual CH with my TF-100 a couple of times a year.

The ColorQ does not test FC levels above 10 ppm (reads high)... This makes the ColorQ useless for doing a SLAM or other tests where your FC can be above 10 ppm... For me anyway, this does not happen very often, so I use the ColorQ for my routine tests and use the TF-100 when I need the FC range or accuracy.

To answer question about which test to use.. I don't really care what test kit you have, but the best tests are the ones done by you and not someone else... As an example... You have been testing your FC for a while and it is almost always at 7 ppm.. then one day you test it and it reads zero... You know this can't be right, so you test it again.. The guy at the store does not have a clue what is normal for your pool.

Thanks,

Jim R.







 

Alset2

Gold Supporter
Aug 16, 2019
50
Cent Fl
Thanks Marty, I have just ordered the tf-100 with PH meter . I will use that and hopefully get a good mix between that and the Lamotte that I can have confidence in .
I really liek the numeric read out . Its much easier for me , but hopefully a good TF-100 will be easier for me to read the color differences
 

beautifulpool

Well-known member
Jun 2, 2019
115
North TX
Alset2, the best money you can spend on your pool (aside from filtration/equipment)
is your test kit.
The TF-100 is a great kit- it’s available on TFTestKits.net and on other pool websites.
It’s a great value. I like especially like the larger size reagent for the CYA & chlorine tests. They use taylor technology’s top rated reagents, and gave me wonderful customer support when I had a lot of “how to?” Type
of water testing questions (when I first began my journey of water testing)
Ps JUST DO THIS
You will NOT be sorry
because at the end of the day,
NOBODY cares about your pool as much as you do.
But you need their technology to achieve accurate results.
 

Alset2

Gold Supporter
Aug 16, 2019
50
Cent Fl
Jim thanks for that detailed explanation and it really clears things up and confirms that my idea is correct about trusting my own testing. This will be extremely reliable once I figure out what test is best and/or the differentials with each kit and what not. I actually like doing these kinds of things !

I am logging my test results on a spread sheet so I can track while i get used to all of this. Right now I test once in the AM and once when I get home just to get a feel for what happens in my pool. I have added acid 3 times and I make notes to that so I Can go back and see cause and effect relationships.
I am going to shoot for TFP target ranges but Im also beginning ti think that maybe this si not as critical as I am making it out to be

BTW- 2 of the store test have 0% on metals in my water...well copper, iron, and phospahtes anyway . I am guessing thats a good thing . The water is very clear ,at least to me .

once again thanks
 

Alset2

Gold Supporter
Aug 16, 2019
50
Cent Fl
Fyi_ i Just read my orig post and it did not save with the spacing I tpyed to seperate the #s, so I just edited it to help it not all be jumbled up -hope that makes since
 

Alset2

Gold Supporter
Aug 16, 2019
50
Cent Fl
Ok, so I am back with more questions about this .

I received the Tf-100 kit last week and have used it 4 times to get used to it. I then decided to order the buffer solutions (all 4) to get a better idea on what I was looking at with these tests and have found some things to be off. I did each buffer test at least 3 times on the Tf-100 kit and one time on my color Q digital tester . Here is what I came up with

CH TF-100=275 2 times and 300 one time, the sample said it was 200ppm - the Color Q read 195
ALK TF-100= 10 drops (100) all three times (no issues) -Color Q read 141
PH TF-100 spot on at 7.2 - Color Q 7.3
CYA...here we go..lol -
On the Tf-100 I did this test many times and the dot does not disappear totally until below 40ppm (supposed to be 50) , so I spent some time trying to see what it looked like at 50ppm , i can definitely see the dot still . The only way I could get it to read 50 is if I stop filling tube the very 1st time I loose sight of the dot. But when I quit pouring at that point I once again can see the dot after a second or 2. Maybe this is how it is supposed to work ??
On the Color Q it read 60 on the 50ppm solution

Am I over thinking this too much? I expected the buffers to be correct and if so I am reading about 33% high on the CH test . I would consider the rest to be close enough to keep my pool in good shape . Heck, maybe all of it is close enough!
Any input or advice is welcomed

Thanks
 

aeh0603

Well-known member
Apr 6, 2016
237
San Diego, CA
How are you performing the CYA test? This test in particular can be skewed quite a bit with varying light conditions. Not enough light and your CYA will read lower than actual, I suspect this may be what is happening for you.

It is recommended to perform this test in full sunlight with your back to the sun (so the tube is in the shade of your body). As you fill the tube, hold the tube at waist level and GLANCE in (do no stare). When the dot is not visible at first glance it is considered to have "disappeared". If you stare you will be able to see (or think you see) the dot for longer and your CYA will read lower than actual. This is the other possibility for what is happening with your results. You can pour the solution back and forth to do the test a few times without having to mix a new sample if you are unsure of your result.
 
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Alset2

Gold Supporter
Aug 16, 2019
50
Cent Fl
I am testing as described Except out in sun...i am doing it on my screened porch with pan roof, could this be a problem? What if its cloudy out, should i wait until its sunny to perform test?

The staring at the dot is certainly a problem.

on pool math, I just subscribed and have a few questions

1- when view my log from TFP it has the time as four hours later than what the app says ???
2- is there a way to log info in using PC?
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
1,628
Chandler AZ
CYA testing results are more accurate when done the way @aeh0603 described. Whatever you do - do NOT stare at the dot.

When testing other parameters besides CYA, be sure to hold the reagent bottle perfectly vertical and allow the reagent drops to fully form on the dropper tip - don't squeeze them off. This will provide more accurate and repeatable results.

PoolMath
1 - What device are you using PoolMath on?
2 - If your PC uses Windows 10 version 16299.0 or higher you can download the PoolMath app from the Microsoft store.
 
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Alset2

Gold Supporter
Aug 16, 2019
50
Cent Fl
Understand on CYA testing and drop formation, makes since .
I currently have it on a Note 10 plus (works fine except for time differential) and Id like to get it on my windows laptop at home but i am having issues with Windows Store. It will not let me install the program . Keeps saying can not access page at this time.