The comparator block that came with my TF-Pro (yellow and red sample cell tops) has pH colors for 7.5 and 7.8 that are almost indistinguishable between them. The other block available on the TFtestkits website, the Taylor 9781, shows clear color differences between 7.5 and 7.8. The Taylor block for sale on the web shows virtually the same distinct differences as my old HDX comparator which is much easier to read when pH is anywhere in between 7.4 and 7.9. I’m using the Taylor reagents that came with the TF kit so can I buy/use the 7891, or just keep/use my old HDX block that appears almost identical in colors and distinguishable differences as the Taylor block? Are other people having a hard time with the middle pH numbers on the yellow/red topped comparator block?
Comparator Block pH Colors
- Thread starter Ray.Pyle
- Start date
- May 3, 2014
- 62,672
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
There is really no need to commiserate over the pH level. If it is 8 or above (purple hue), add acid to lower the pH by 0.4 points.
Whether the pH is 7.5 or 7.8 is really immaterial.
Whether the pH is 7.5 or 7.8 is really immaterial.
I am starting to get comfortable with the idea that as long as it’s higher than 7.2 and less than “purple” then I can relax from constant adjustments to find whatever hue is equal to 7.5. Smiling as I write this: as an engineer, however, logging daily tests as guesses on somewhere in the mid-sevens +/- .4 irks my geekish need for better accuracy and the notion that comparators that compare things should be comparable 
. No further entries this post - going swimming.
. No further entries this post - going swimming.
Note that the reagents that come with comparators cant always be interchanged. Theres two different phenol red reagents each for a specific comparator.I am starting to get comfortable with the idea that as long as it’s higher than 7.2 and less than “purple” then I can relax from constant adjustments to find whatever hue is equal to 7.5. Smiling as I write this: as an engineer, however, logging daily tests as guesses on somewhere in the mid-sevens +/- .4 irks my geekish need for better accuracy and the notion that comparators that compare things should be comparable