Do You Need a pH Meter to Test Pool pH?

[PoolDoc]

Many color-blind people can use most of the tests in the Taylor K-2006 without problems. Color does is not usually a problem with the DPD-FAS test for free and combined chlorine, and also not for the cyanuric acid test.

The changes in total alkalinity (red/green) and calcium (pink/purple) tests can often be perceived even with color blindness.

But, the pH test, which is the only color MATCHING test in the K-2006 may be a problem. If you have difficulties with color perception, you may need a pH meter. You can check yourself against the images below, taken from the Wikipedia article (http://en.wikipedia.org/wiki/Color_perception_test). The first image is NOT a color test, but gives you an idea of what you're looking for. A key follows.

10 second cycle -- if you don't see it, wait 10 seconds!

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http://upload.wikimedia.org/wikipedia/commons/c/c7/Ishihara-12.gif
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Test images
-- for best results, back up about 3 feet from your monitor --

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1. Ishihara #1
http://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Ishihara_1.PNG/768px-Ishihara_1.PNG

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2. Ishihara #19

http://upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Ishihara_19.PNG/768px-Ishihara_19.PNG

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3. Ishihara #11

http://upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Ishihara_11.PNG/768px-Ishihara_11.PNG

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4. Ishihara #23

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Ishihara_23.PNG/768px-Ishihara_23.PNG

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5. Ishihara #9

http://upload.wikimedia.org/wikipedia/commons/thumb/e/e0/Ishihara_9.png/768px-Ishihara_9.png

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1. Ishihara #1 => normal color vision sees "12"
2. Ishihara #19 => normal color vision sees nothing; red/green blindness sees "2"
3. Ishihara #11 => normal color vision sees "6"
4. Ishihara #23 => normal color vision sees "42"
5. Ishihara #9 => normal color vision sees "74"


PoolDoc / Ben

[PoolDoc]

Unlike 'wet' pH tests, pH meters are not necessarily 'correct' out of the box, but must be calibrated. This is NOT optional. Also, these are cheap-o Chinese kits -- most probably work well, but Chinese products tend to have poor quality control. You MUST validate your meter, by comparing results with a drop test, used by someone who is NOT color blind! Also, pH tips are THIN glass, and will not survive a fall.

Inexpensive units from Amazon

Buffer pack (http://www.amazon.com/exec/obidos/ASIN/B06X3TKTBC/poolbooks/)
pH Meter (http://www.amazon.com/exec/obidos/ASIN/B07BVRGJ18/poolbooks/)

[JimK]

Interesting.

I’m “color blind” (a misnomer). I do fine with the pH test (confirmed by my non color blind spouse), but struggle with the CH test. I have a alternate procedure for CH that you helped me with years ago that helps. Still, I just have my spouse do the CH test for me. :)

[FormerBromineUser]

When I looked at the Wikipedia article, it said the following about the second image:
Ishihara Plate No. 19 (Nothing (hidden digit plate); Red-Green deficiency sees 2)

[PoolDoc]

Thanks, correction made.

[JimK]

When I looked at the Wikipedia article, it said the following about the second image:
Ishihara Plate No. 19 (Nothing (hidden digit plate); Red-Green deficiency sees 2)

I just see a bunch of dots. :D