pH color too intense

[engrav]

so with 5 drops R0004 color is too intense to read
with 4 drops still too intense
with 3 drops reads well

why is recommended 5 drops too intense?
is 3 drops Ok?

 

[Bama Rambler]

What is your pH?
Which kit are you using?
Are you sure its R0004 reagent you are using?
How old is the reagent?

 

[jblizzle]

Sounds like you may be using the wrong reagent for your test tube ... there are two that are different "strengths" R-0004 and R-0014

Did you recently buy a reagent refill? Which kit's comparator are you using?

The number of drops does not really matter if this is just a case of the wrong reagent (4 vs 14).

There are other threads about this if you search:
ph-phenol-red-taylor-reagents-r-004-and-r-0014-t37257.html

 

[engrav]

as always thank you

checked out the threads but all seem to discuss 0014 vs 0004
but this is clearly R-0004 and K-2005
but Bama asked about age of reagent, ie quality so...

I have been refilling the little R-0004 from a big one so can put it away in the case
?contaminated

I have another bottle of R-0004 and tried it, works fine
Then I emptied the little bottle, rinsed it out, refilled it and it now works fine

I guess I contaminated the little bottle somehow

 

[Bama Rambler]

That's good detective work you did finding that out.

I wonder what the contaminate was?

 

[engrav]

I think will never know but a rule(s)...
if test does not work, try a different bottle
and maybe
do not refill little bottles
or if refilling
rinse out and start fresh
or something
or not

 

[chem geek]

I have both the Taylor K-2006 and the TFTestkits TF-100. The R-0004 pH test with the K-2006 is also dark for my comparator and I use 3 or 4 drops instead of 5 so this does happen and it's been that way for multiple bottles so I don't think it's contamination, at least in my case. It could be that the comparator has faded as it is older -- I'd have to get a new one to be sure. Since it's the hue that is important in comparison, using fewer drops is OK unless the chlorine level is higher in which case there might not be enough chlorine neutralizer so you may get a falsely high pH reading (though with CYA in the water it takes some time for the chlorine to affect the pH dye).

 

[engrav]

emailed Taylor
they said both of my bottles as identified by lot # should work, not expired
they also said if 5 drops does not work something is wrong; use another bottle
so it goes...

 

[engrav]

well
now 9 months later same problem, pH color too intense to read
will need to try new bottle and new comparator

 

[jblizzle]

Did you ever try using fewer drops?

 

[engrav]

Did you ever try using fewer drops?

I did and that makes it better
but Taylor person said "if 5 does not work, something is wrong; you should use 5"
and chem geek said fewer drops could mean less neutralizer and falsely high pH
so may be time for new stuff, may be time for the tfp stuff
in fact
I will go read about it now

 

[engrav]

so ordered the TF100 large
will be sad if it does the same thing

 

[chem geek]

I almost always need to use 3 drops and never more than 4. Perhaps my comparator is faded, but I wouldn't worry that much about using only 3 or 4 instead of 5.

 

[engrav]

I almost always need to use 3 drops and never more than 4. Perhaps my comparator is faded, but I wouldn't worry that much about using only 3 or 4 instead of 5.

Hi & thank you

based upon using 3 and 4 drops, I think you are correct

but it bugs me
so I got a new bottle

now all is fine, funky colors gone