Am I testing pH correctly??

crek31

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Jun 28, 2009
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I'm using a Walmart HTH kit for this. Just the block and red drops. I think I have read to do the test in sunlight (sun at my back) and to hold it up in front of a white background to read the result. I have a pretty hard time distinguishing the top three colors, but it is easier when I hold it in front of a white thing. If I hold it a few inches in front, it looks like 7.5. If I put it up against the white thing, it suddenly looks like either 7.8 or maybe even 8.2. When you guys say to hold in front, do you mean right up against, or a couple inches away?

Also, is there a drop test akin to the FAS-DPD test for pH for those of us who have trouble with the color matching?

Thanks!
 

Richard320

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Jan 6, 2010
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I just hold the vial at arm's length and the white backdrop is a few feet behind. I like to let it get a little blurry - I'm looking at the color, not the shape! Besides, all we do is estimate anyway - it's a pretty big jump between values.

And no, there is no foolproof pH test. I asked already.
 

Miranda

Well-known member
Jan 20, 2008
161
Northeast Florida
I have LOTS of trouble distinguishing the color. I have a Taylor kit, and an old Walmart kit. The Taylor kit is in even increments (7.2, 7.4) while the Walmart kit is in odd (7.3, 7.5) When in doubt, I do both. Sometimes one kit is easier to read, other times the other, depending on the increment.

I try to focus on the difference between the COLORS rather than the lightness or darkness of the shade. For my eye "orangeness" is the key to my ideal ph of 7.4. At 7.6, I see pure pink, no orangeness, and at 7.8 I start to see a purplish cast. On the low end, as the pH drops, I lose orangeness in favor of yellow.

The chlorine is even harder for me to distinguish, since it relies on shades of the same color.
 

JasonLion

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The background should be at least several inches away, and more is better.

Reading the colors in the PH test takes some practice. Good lighting helps a lot. But in the long run it is practice that really makes a big difference.
 

Woodberg

Well-known member
I also have trouble distinguishing between the different shades of pink. I have a lot of aeration so I'm always fighting PH rise. One thing I've been doing to help is use the acid demand test. I'm using the Taylor K-2006 test kit. By adding a drop of acid demand reagent, I can see the color change and it helps determine whether I really need to add acid. If it turns more orange I may add acid. It the extra drop causes the color to change to yellow, I just leave it alone.
 

257WbyMag

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Feb 23, 2008
5,061
Denton, TX
Woodberg said:
I also have trouble distinguishing between the different shades of pink. I have a lot of aeration so I'm always fighting PH rise. One thing I've been doing to help is use the acid demand test. I'm using the Taylor K-2006 test kit. By adding a drop of acid demand reagent, I can see the color change and it helps determine whether I really need to add acid. If it turns more orange I may add acid. It the extra drop causes the color to change to yellow, I just leave it alone.
I am also one that uses the acid demand to help detect the differences. Always have. Most people don't bother with it but it really helps me.
 

crek31

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Is the acid demand testing stuff in duraleigh's TF100 kit?
 

Durk

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Jun 14, 2007
654
New Jersey
I use my skimmer lid as my white background. I hold the lid at arm's length with one hand and the block at reading distance with the other. I'd use a white wall if I had one, but all I have is blue (pool/sky) and green (grass/trees).

I also use the acid demand because I have trouble with the red shades in the higher values. If one drop takes me to below 7.5, I leave it alone. If it takes it to 7.5 or above, I hit it with 1/3 of a jug (amount from Taylor table for my size pool) and retest. Works for me.
 

JasonLion

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No, the acid demand reagent is not included with the TF-100.

You can add it on by getting a bottle of Taylor R-0015 Acid Demand Reagent.
 

crek31

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Jun 28, 2009
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Since I just have a temporary pool with more or less disposable equipment, I've never worried that much about pH. Have just started to care a little due to some hair issues my kids are having, and wanted to be sure it wasn't attributable to poorly balanced water (and my pride couldn't take it if my pool was not as awesome as I like to think it is). Given that the color block should be away from the white backdrop, I think I'm okay and that the pH is 7.5. I know TA is high (210 or so), but have never cared about that either since pH has seemed in range and water looks and feels great. Thanks for all the replies, and I'll add on some R-0015 next time I place an order. Unfortunately I just got my refills so it won't be til next year in all likelihood. Thanks again!
 

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