CYA present even if I have not add it to fresh water

Pysiek

LifeTime Supporter
Apr 3, 2012
450
Frankfort , Illinois
So I tested my water last night. CYA came up to be about 12. Is this is correct if I just filled my pool and have not yet add it? Or is it just a reading from the solution I added to the mix ?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
23,647
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
What test are you using that can give you a value of 12 on the CYA test?

CYA does not naturally occur in water.
 

Pysiek

LifeTime Supporter
Apr 3, 2012
450
Frankfort , Illinois
What test are you using that can give you a value of 12 on the CYA test?

CYA does not naturally occur in water.
I bought the LaMotter ColorQ Pro 7. I have to add a pill to the glass tube and crush it to get CYA reading. So I assume the 12 might come from the pill? Or basically the unit is faulty?
 

Mdragger88

Bronze Supporter
Jun 1, 2018
1,760
Hernando, Ms
Pool Size
26000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
It shows you have an inline chlorinator- trichlor pucks have cya - also unless u removed every drop of water before you filled there could be cya in the water.
 

Donldson

TFP Expert
LifeTime Supporter
Jun 12, 2009
4,657
NW Ohio
They don't "put" CYA in the pucks, the pucks are made of trichlorisocyanuric acid. It's a chemical compound that has CYA and chlorine in it.

If you freshly filled yesterday then you do not have CYA in your water. The ColorQ is wrong. Sadly that's not surprising, it isn't a reliable piece of equipment.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
20,831
Bedford, TX
PY,

I also have the ColorQ and find it to be very reliable and repeatable, but not necessarily accurate. Especially with the CYA test. I have found, over the past 6 years, that the CYA test, in particular, will vary with each batch of tablets. In one case, I found that if I ran the CYA test with one batch of tablets vs. another batch of tablets, that I had about a 25 ppm difference, on a consistent basis between the two.

No matter what test you use, the CYA test is subjective anyway and most of the time, being close is good enough.

As a test, I would use tap water, and run another couple of CYA tests, and see what the results are. If they also read 12 ppm, you will know for sure that your ColorQ is reading high when using your current batch of tablets..

I use my ColorQ, because I have three pools and I like the portability and ease of use.. That said, I do not rely on it for accuracy. I generally want to just compare last weeks readings with this weeks readings. This allows me to see how my numbers are trending.. If I want to know for sure what my numbers are, I use my TF-100 test kit.

As an analogy, I use my ColorQ as a standard wrench, and I use my TF-100 as a Torque wrench.

Thanks,

Jim R.
 

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scottts

Gold Supporter
Nov 13, 2019
168
Gilbert, AZ
I will try the tap water and probably one more time pool water with another pill. Anyone ever did a test where they compare TF-100 to ColorQ results
I have done side by side testing with a Taylor K2006 and the ColorQ with the tabs. I originally got the ColorQ because I wanted an "automated eye" for the CYA test because I was having difficulty knowing if I was doing it right.

Unfortunately I didn't save my logs but I remember the ColorQ was reasonably close to the K2006C on FC, pretty dead on for pH, Completely unusable on TA (it often just read lo - not even a number - K2006C was at 60), too low on CH, and reasonable (about 10ppm lower) on CYA.

I did like the ease of the ColorQ but I've stopped using it because of its issues with the TA and CH tests and my pool is now settled in and I don't need to test things as often.

Funny thing is when looking at the colors of the reacted ColorQ tubes, it sure seemed like the actual reagents worked OK. I sort of came to believe one of the color sensors in the ColorQ photometer was either dead or out of calibration badly. Probably should have requested to have it repaired but I just let it slide.

Oh, most of this side by side testing was done in the winter with 58 degree water if that matters.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
20,831
Bedford, TX
Scott,

The ColorQ measures Total Hardness and not Calcium Hardness, so depending on the local water supply, the difference can be a lot... I know they label the test as CH, but it is actually TH..

Not sure when you did your comparison testing, but they had a bad batch of TA reagent.. They sent me an e-mail warning, and then recently sent a replacement bottle of reagent.

Thanks,

Jim R.
 

scottts

Gold Supporter
Nov 13, 2019
168
Gilbert, AZ
Ah yeah I remember that CH-TH difference now.

I tested this last winter. I didn't get an email or replacements so I amuse things we're OK then.
 
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