Chem Testing Reality Check!

paganok21

Member
Mar 3, 2022
24
Rio verde, AZ
Pool Size
10000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
I just wanted to take a moment and share yet another example of why TFP expertise is so helpful. I wanted to have my CYA double-checked because that darn dot messes with my eyes sometimes. ;). I’ve been slowly adding stabilizer and wanted another check on where I’m at. So I popped into Leslie’s and they graciously did a full pool water test and tried to sell me their NoPhos, Alkalinity up, and 1.5 lbs of their Fresh n Clear. It was odd to me because before leaving home, I had just ran my own tests and my water was crystal clear with results all in range. Reading all of our TFP forums educated me on this situation and all the chemicals that pool stores will try to push. Still, I’m shocked at how (and why) the results are so different! Especially with the free and total chlorine and salt levels. Has anyone else experienced this? It’s particularly concerning that Leslie’s reports my Total Chlorine so high with free chlorine so low, yet my results are near perfect.

Below are the Leslie’s results vs mine. I use the Taylor K-1005, the Taylor FAS-DPD Chlorine, and the Taylor K-1766 Salt test kits, fyi.
FC: Leslie’s 2.15. Mine: 7.8
TC: Leslie’s 5.51. Mine: 0
PH: Leslie’s 7.4. Mine 7.6
TA: Leslie’s 69. Mine 90
CH: Leslie’s: 388. Mine 450
CYA: Leslie’s: 64. Mine 60
Salt: Leslie’s: 3585. Mine: 4600.
Phosphates: Leslie’s: 556
 

Mdragger88

Bronze Supporter
TFP Guide
Jun 1, 2018
6,438
Hernando, Ms
Pool Size
26000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
You can take the same sample in again in 5 minutes & probably get different results.
Aside from that here are some reasons for some of the differences.
FC - your sample could have degraded on the way to the store
Cc - same issue + how well do they clean their stuff between customers, perhaps that’s someone else’s cc’s 🤷‍♀️
There’s also a difference between the sample sitting in a “clean” container for a couple minutes while you quickly do your own tests
& it sitting in that same container for an extended period of time. Unless you boiled the container first there will eventually be some interference the longer it sits.
Ta- they use “adjusted” ta in which they subtract 1/3 of your cya from your actual ta so 90-21= 69
Salt- meters (if calibrated) & strips are around +- 500 ppm accuracy
The k1766 is around 200+- accuracy.
The fact that the pool water sample can change after being transported/stored for extended periods makes relying on the pool store for accuracy a bad idea even if their tests we’re always 100% then throw in the other variables like who’s performing the tests that day, how well are they trained, how well they clean equipment between customers, how often do they calibrate their equipment & what does their computer want to sell you this week etc.
 
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paganok21

Member
Mar 3, 2022
24
Rio verde, AZ
Pool Size
10000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
You can take the same sample in again in 5 minutes & probably get different results.
Aside from that here are some reasons for some of the differences.
FC - your sample could have degraded on the way to the store
Cc - same issue + how well do they clean their stuff between customers, perhaps that’s someone else’s cc’s 🤷‍♀️
There’s also a difference between the sample sitting in a “clean” container for a couple minutes while you quickly do your own tests
& it sitting in that same container for an extended period of time. Unless you boiled the container first there will eventually be some interference the longer it sits.
Ta- they use “adjusted” ta in which they subtract 1/3 of your cya from your actual ta so 90-21= 69
Salt- meters (if calibrated) & strips are around +- 500 ppm accuracy
The k1766 is around 200+- accuracy.
The fact that the pool water sample can change after being transported/stored for extended periods makes relying on the pool store for accuracy a bad idea even if their tests we’re always 100% then throw in the other variables like who’s performing the tests that day, how well are they trained, how well they clean equipment between customers, how often do they calibrate their equipment & what does their computer want to sell you this week etc.

Well said. Thanks for the stats on the typical accuracy +\- variables. The pool store is a 40 minute drive from my home so perhaps that contributed. Or, perhaps it was indeed a tester error. She accepts my sample and tells me it will be just a minute. She takes care of a customer while I stand and patiently wait. About 10 minutes later after customer is complete, she apologizes to me that she forgot to ‘push the button’. Just when I began to lose confidence in their process, my report prints out and the first thing said to me was that my results are astounding and I have some serious problems going on in my pool. 🤦🏽‍♀️
 
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Mdragger88

Bronze Supporter
TFP Guide
Jun 1, 2018
6,438
Hernando, Ms
Pool Size
26000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
I used to depend on the local pool store for comparing my salt strip readings- they have a meter so I would just try to average the two. It never failed, even though I told them salt test only they tested everything & then always proceeded to tell me how high my fc was or how low my ta was & start asking me questions/giving me advice about my water. Soooo glad I got the k1766 - now I just buy my bleach twice a year & leave.
 
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PoolStored

Gold Supporter
TFP Guide
Jun 24, 2021
2,503
Ashtabula, OH
Pool Size
30000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60

markayash

Gold Supporter
TFP Guide
Mar 21, 2016
4,181
Atlanta Ga
It’s no different they being told your variable speed cross member is bad while getting your oil changed. And they usually through in “ if you don’t do it now you might die driving home and it’s only $750”

And and go just sit in a tire store and listen. 90% of them will say “ wow ok”
 
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paganok21

Member
Mar 3, 2022
24
Rio verde, AZ
Pool Size
10000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
It’s no different they being told your variable speed cross member is bad while getting your oil changed. And they usually through in “ if you don’t do it now you might die driving home and it’s only $750”

And and go just sit in a tire store and listen. 90% of them will say “ wow ok”

Knowledge is power. I’m super grateful for this site!
 

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