Teading PH comparator difficulty


Active member
May 7, 2011
I always seem to struggle reading Ph scales on the test comparator. I have tried using a variety of backgrounds and lighting and since my pool has always been an "acid eater", I test nearly every day. Is there another Ph test kit with better resolution or an easier to read scale? Almost forgot. I am using the one with the R-0014 reagent

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
The test comparator you are using is really the best method of home testing. I too have days where my eyes just don't seem to want to play nice with that viewing glass. :hammer: Some people like a white paper as a background, but for me personally, I use the siding on my house. I have an off-white beige color that seems to help me focus better on the color change. I also need to have it somewhat protected from direct sunlight as that tends to just make it a mess to read as well. In short - experiment with what works best for you.

Meters that may be available to the public don't seem to have the ratings that make them reliable for us. Here is an interesting discussion about that subject: Electronic PH Meter


Silver Supporter
Sep 17, 2017
Silicon Valley, CA
I also struggle with the colors on the higher end of the 7s, where my pH always pushes to. I only had the small comparator block with R-0014. My biggest complaint is that the scale on that block goes 7.5 to 7.8 to 8.2. There is nothing in between 7.8 and 8.2.

So I bought the larger comparator block 9056 and the associated reagents R-0004 and R-0005. This larger block scale is every 0.2 (7.6 to 7.8 to 8.0). That has really helped me differentiate between the salmon colors near 7.8 and rich pinks at 8 and above.

An upside to this 9056 block is that it has the textured CYA tube, so it also gives me a secondary measurement option for CYA.


Active member
May 7, 2011
I remembered an older test kid in th closet and low and behold it had the 9056 with some very old R004. I tried running a test and it came out looking like fire engine red! Old reagent obviously. In looking at the color scale, I would probably struggle with this one too. Wish there was a drop test similar to the chlorine test.