Best way to test pH

Shapmaui

Well-known member
Jun 10, 2018
51
Kihei HI
One last question for the day...I have the TF-100 test kit which comes with the K-1000 pH and Chlorine kit.
To determine pH you guess at the closest color match on the kit and liquid for measuring pH and look across to the pH number- after adding 5 drops of
phenol red. Sometimes the liquid color isn't just like what is available on the color choices.
I find it's very subjective. Is there any system to test pH with better accuracy?
Or is this color system good enough...?
I have read about pH meters but they seem way too finicky and expensive. Thanks!!
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
15,841
Laughlin, NV
Be sure you use a white background to compare the pH readings.

I use 4 drops instead of 5. For my eyes, I get a better color match.
 

Shapmaui

Well-known member
Jun 10, 2018
51
Kihei HI
Now you're throwing me a curve ball...
Wouldn't using 4 drops instead of 5 would make the test color a little lighter? Thus possibly giving a false lower reading?
 

cfherrman

TFP Guide
May 10, 2017
2,207
Hays, Kansas
If you still struggle you could pick up the Taylor pH/acid demand test. It's the same except you can add (special kit acid) acid to your test to get the shade to drop and see how much acid you need to add to your pool. You can also use pool math to start figuring what your pH was with a little math.

There are also pH meters but they have upkeep
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,956
San Dimas, CA (LA County)
I get the best results by holding the test block at arm's length and squint a little so that the numbers and all get blurry. Against a light background (I use a white patio chair across the table) I have no problem determining whether that shade somewhere between 7.2 and 7.5 is 7.3 or 7.4.
 

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