Yesterday I found a post that someone referred to picture tips on a Taylor test kit that was help for someone reading a TF-100 kit. Like an idiot I didn't bookmark it. Anyone know what I'm referring too?
I've also noticed this. It seems the PH test in the TF-100 is open to a lot of interpretation due to the color chart. Is there another PH test that can give more accurate results? Perhaps one with a color-changing indicator like the DPD chlorine test?
If you have trouble reading the colors on the PH test you can get a ColorQ. It is a little expensive and suffers slightly more from high chlorine level interference, but does give a very accurate digital readout of FC, CC, and PH. It also does other tests but they are not as good as the titration tests in the TF-100.
The standard PH test is really the best choice for most people. With a little practice you can learn to read it very precisely.
Sorry for any pun, but this is not a "black and white" issue. It's what works best for you. I personally find it easiest to hold the comparator up to a blue sky with no white paper behind it....that doesn't make my method it right, it's just what I'm used to.
Find a method that your comfortable with and then use the same method each time for repeatable results.
I, too, have a hard time matching colours on the comparison tubes. I think colour perception wanes with age somewhat.
While I cannot tell the difference on the TC bar for values 3 or 5 I can see that it's not 1. 2 is up for grabs most days. Since I do the titration twice a week it's good enough for me knowing that on the in-between days the TC is at least equal to or greater than 2.
pH is similar. I know that it's not 6.8, 7.2, 7.8, or 8.2. Therefore, it's between 7.3 and 7.7. Again, good enough.
Last season I stressed over not being able to do a better job reading those colour bars and yet the pool was clear and clean all season. IT doesn't know that my eyes don't work as well as they used to