What's my pH?

[MITBeta]

Hi All,

Went to measure pH for the first time with a new bottle of indicator and got this. pH was 7.5 at the end of last season and 7.5 when I opened 10 days ago. Fill water has always been in the 7.s as well and produces a similar result to this.

 

[JoyfulNoise]

What’s your FC?

 

[JoyfulNoise]

I see from your PoolMath Logs that your FC is 9.5. FC over 10 (your sample could have had higher FC) can cause the phenol red to convert to a different compound that turns light purple when the pH is above 6.5. What you are seeing there is likely the result of the FC being too high.

Take a water sample and dilute it 1:1 with distilled water and then retest.

 

[MITBeta]

That was my first thought, too. I but my fill/tap water is showing the same result.

 

[MITBeta]

I think I figured out at least part of the problem: My TFTest kit refill came with R-0014. My Taylor comparator block says to use R-0004. Should I get more R-0004 or a comparator that works with the R-0014? It doesn't look like TFT carries R-0004. Is this the right block to use for R-0014?

Taylor 9781 Comparator Block

tftestkits.net

 

[JoyfulNoise]

ooooooo ... yeah, R-0014 is used with the smaller volume comparator block. The midget comparator holds about 4.5mL of water while the larger comparator holds 9.5mL. You definitely will not get correct looking results with R-0014 in the larger block.

You can get R-0004 on Amazon from lots of different retailers. Just pick one and hope they send you fresh'ish stuff ... Amato Industries is very good about sending good stuff and I think you can direct order from them.

 

[MITBeta]

Thanks. I ordered R-0004 from Amazon and will grab a comparator for the R-0014 next time I order from TFT (the comparator is cheaper than the indicator...).

 

[JoyfulNoise]

My guess is that your pH is fine, probably around 7.8. The R-0014 is so much more diluted than the R-0004 that you just can't get enough color depth to compare it.

I use a K-1004 kit for my daily testing and save all my "big boy" reagents for the weekend.

 

[Newdude]

yeah, R-0014 is used with the smaller volume comparator block

Matt what is the current thoughts on this ? They have gone back and forth many times here.

The block pictured has the same colors as my little block from 7 to 8 and the only difference is the added colors for 6.8 and 8.2, which fools the eyes looking at them side by side.

If they both use phenol red, and the amount of drops used doesn't matter, say, using 6 instead of 5 with the little block, then why aren't they interchangeable with either 2 or 10 drops (ish) until the color lines up with the block ?

 

[MITBeta]

That's better:

 

[JoyfulNoise]

To answer the previous question - you really can’t interchange the reagents and comparators and just adjust the number of drops in any practical way. The comparator block color swatches are based on a specific concentration of the phenol red reacting with standardized pH test solutions. Not knowing the exact concentrations of phenol red makes it hard to figure out. I do know that even one drop of the R-0004 reagent in the midget comparator gives the wrong color intensities. I’m sure using the R-0014 in the larger comparator would require like half the reagent bottle. So it’s just not practical.

 

[mknauss]

My TFTest kit refill came with R-0014. My Taylor comparator block says to use R-0004.

Please email TFTestkits with that information. Feedback on any QC issues is appreciated.

[email protected]

 

[MITBeta]

I will, but I don't blame them. I bought a TF-100 refill set for my K-2006C kit. I assume they supply the reagent for the block that came with the TF-100. Though it would be nice if R-0004 was offered as an option.

 

[proavia]

Deleted
I see you ordered a TF100 refill kit that comes with R0014.

 

[mknauss]

I will, but I don't blame them. I bought a TF-100 refill set for my K-2006C kit. I assume they supply the reagent for the block that came with the TF-100. Though it would be nice if R-0004 was offered as an option.

I see. If you want something unique, you need to communicate that.

Take care.

 

[MITBeta]

I didn't realize when I ordered the refill kit that it included phenol for the other comparator. My mistake.