PH Testing Question - slightly off topic

Jun 20, 2007
9
#1
I have recently had a whole house water conditioning system replaced (acidic well water -- (6.4) ). I've got a Taylor k2006 test kit (which I have been using for 1 year on my pool) and the tap water is now reading way over 8.0 which is the limit of the kit. The company that installed the system is saying their testing is showing it to be in acceptable ranges (7.2-7.6) and the swimming pool kits are not as accurate as their 'laboratory'. This sounds like a load of BS to me. My question is what is the accuracy of the PH test (Phenol red r-0004 44ML 5 drops - new reagent) in the K2006 kit? I would assume it's fairly accurate, and the testing procedure is not rocket science so I can't imagine any issues with my execution.
Any insights would be appreciated.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#2
The standard phenol red PH test is very accurate as long as the free chlorine level is below 10. With a little experience and good lighting it can be read to +-0.1 or perhaps a little better and practically anyone can read it to +-0.2. Properly calibrated and operated laboratory equipment can read PH to better than +-0.01, but many places don't seem to take the time to maintain the calibration.
 
Jun 20, 2007
9
#3
Thanks jason.

Before I read them the riot act, anything else that could potentially be in the well water that could throw off the results?
 

stevenbrla

LifeTime Supporter
May 11, 2007
237
Baton Rouge, LA
#4
I think before you could push them too far, you would still have to present them with a 3rd party test.

its not terribly uncommon to have different answers... especially when one party wants them to lean a certain way...

Find out what lab they use, then find another one to do a test for you.

Either pay someone to do a test, or think of someone you know who might work in/near a lab.

industrial, maybe a medical lab, municipal water suppliers... anyone...?

if you live near me.... i'll send it to work with my wife on Monday...
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#5
Very high iron levels (more than 10 ppm), high chlorine (more than 10 to 15 ppm) and high bromine (more than 20 to 30 ppm) are the only listed interferences for the standard PH test.

Keep in mind that if the alkalinity is very low (unlikely but easy to test), it doesn't take much contamination to change the PH significantly.
 
Jun 20, 2007
9
#6
Thanks all. I took a sample to one of their competitors. They tested it and PH is reading 8.2. I'll have a conversation with the folks who installed the neutralizer and suggest they re-test and adjust it so it is not overcompensating.