Drop Test for Ph?

[jj]

Is there a drop test for Ph? Or have I missed the boat?
I am having trouble reading the colorator that came with my TFP kit.
I see people posting numbers that are not on the colorator. Are they just guesstimating?
I would like a exact number Not my wife and I guessing what shade it is.
Is there a better way to do this?

 

[JasonLion]

No, there isn't a titration (count the number of drops) test for PH. With practice it is possible to read the PH color reliably to the nearest 0.1. You might be interested in the ColorQ. It has a very good PH test with a digital readout as long as your FC level is below 10, though it is somewhat expensive. The FC and CC tests are also good, again if FC is below 10, but it's other tests are only so so.

 

[jj]

That can't really be true can it? When the colorator goes from 7.2-7.5, 7.5-7.8, 7.8-8.2.
How can you determine you are within 0.1 guess? I'm just asking?
I think hub has practiced enough. He's aspiring to Waterbear's theme....I've tested more water than....
I walk over and glace at it quickly to make sure we aren't staring at it
We opened to a beautiful pool after the winter, by the way. Thanks to BBB and this forum.

 

[Guest]

He's aspiring to Waterbear's theme....I've tested more water than....
.

ROFL!!!
I started 'testing water' when I was a kid and got into aquariums, continued in high school when I was in an accelerated science program and was doing research in seawater chemistry at the University of Miami, and getting into Marine aquarium keeping, which I still do. This does NOT include all the water I have tested for pools and spas both professionally and personally!
To answer your question as to why some people post numbers for pH that are not on your color comparator, Taylor makes two pH color comparators tha use different reagents (they actually make a few more than that but the two most common are the ones I am referring to). The one you have is a wide range (6.8 to 8.2) comparator but it is marked in about .3 increments. This is actually fine since you are testing a pool, not doing a chemistry experiment. Their other comparator has a range from 7..0 to 8.0 (not quite as useful when you need to lower TA) but it is marked in .2 increments.. The nice thing about the comparator you have is that it has a marking for 7.5 which is actually the 'sweet spot' for pH.
A good way to get an idea for the pH colors is to add a tiny speck of baking soda to some plain water and put it in your vial and add the pH reagent. Your pH should be 8.2. Now add some diluted vinegar a drop at a time and watch the color changes as it goes from purple to red to orange to yellow as the ph drops. With a bit of practice you soon learn to recognize the colors and the pH without the comparator. Once you can do THAT you can certainly say that you have tested more water then you care to think about!

 

[rimshaker]

It really depends on an individual's ability to differentiate between similar shades of pink. Naturally it can be subjective; but with enough practice you can at least correctly guesstimate if the reading is closer to one number or the other.

At the end of the day I just close my eyes and pray the reading lands on an exact color band

 

[Guest]

It really depends on an individual's ability to differentiate between similar shades of pink. Naturally it can be subjective; but with enough practice you can at least correctly guesstimate if the reading is closer to one number or the other.

At the end of the day I just close my eyes and pray the reading lands on an exact color band

The phenol red pH test is NOT shades of pink. The color changes are as follows (and it doesn't matter WHOSE teskit you are using, the colors are determined by the indicator, phenol red, which is almost univeraslly used to test the pH of pools and spas):

6.8 and below yellow
7.0 yellow with a bit of orange
7.2-7.3 orange
7.4-7.5 red-orange
7.6-7.7 red
7.8-8.0 "pinkish" or "cool" red but not quite purple
8.2 and above purple