How does algaecide affect R-0014 performance?

[DeptOfMeteors]

How old are your reagents? Most will last 2 years if stored properly (cool, dry, dark place). If u are getting consistent readings based on your dosages it is unlikely they are bad.
The oto test (while not super accurate) can help reaffirm the results of the fas/dpd test. The ph test can change color if left alone a while. There are several different factors involved in how quickly this may occur.
For this reason it is recommended to read all tests immediately, record the results, then discard the sample.
Here’s some good info on common testing errors as well as how to identify bad reagents

Water Testing Errors - Further Reading

www.troublefreepool.com

The reagents are 3 or 4 months old. I keep them cool and dark and in the carry case they gave me.
The article, while interesting and possibly helpful in the future, doesn't seem to have anything that clearly explains how the pH test w/R-0012 would be so chromatically dynamic (I especially don't know what to make of "high levels of chlorine > 10 ppm can cause a false low or 0 chlorine reading"). I am partly colour blind (I fall over backwards on Ishihara tests), but every time I get someone to spot me, my colour perception over these tests are correct.

To confirm chlorine interference, you can add a drop of thiosulfate to the pH test sample to neutralize chlorine before adding the phenol red.

That could be helpful. But... I'm not sure the TF-Pro has that, does it?

 

[JamesW]

R-0007 is thiosulfate.

 

[DeptOfMeteors]

Ok, I did the pH test again and this time I put a drop of R-0007 in it first (and then made sure it was mixed). Once I dropped in the R-0012 again, it turned the same dark 7.2 that it gave me yesterday. However, over the next couple of minutes it migrated more to the 7.5 colour. Then after another 5, it was somewhere between 7.5 and 7.8. Is it normal that the colour migrate like that over time?

 

[JamesW]

Once I dropped in the R-0012 again, it turned the same dark 7.2 that it gave me yesterday.

R-0012?

What do you mean a "dark" 7.2?

What FC reading are you getting with the FAS-DPD?

Are you sure that you are doing the test FAS-DPD test correctly?

 

[DeptOfMeteors]

R-0012?

What do you mean a "dark" 7.2?

What FC reading are you getting with the FAS-DPD?

Are you sure that you are doing the test FAS-DPD test correctly?

I guess I mean R-0014.
I mean darker than the guide, like in the pic I posted this morning.
My FC tested at 8.5, actually, so from what I've been told, the R-0007 wouldn't have made a difference
I'm not sure about anything anymore. But I've read the guides and everything about how to take the measurements and been doing plenty of them in the last month.

 

[Mdragger88]

The pic looks like 7.2 or a scootch above to me which is totally fine (although pics aren’t always the same as real life). There aren’t marks/colors for every increment so it’s ok if it falls in between. Just Do the drops, invert the comparator a couple times, match the color (as closely as possible) , record the result & carry on. Having a white background can help with the color matching.
No sense in letting the sample sit as it may change color & that just causes confusion.

 

[JamesW]

I would call this 7.4.

If the sample gets darker as it sits, it is usually from chlorine combining with the pH indicator and converting it into chlorophenol red.

Maybe try some new reagents and/or get a pH meter.

Try the bigger tube with R-0004.

 

[Bperry]

The pic looks like 7.2 or a scootch above to me which is totally fine (although pics aren’t always the same as real life). There aren’t marks/colors for every increment so it’s ok if it falls in between. Just Do the drops, invert the comparator a couple times, match the color (as closely as possible) , record the result & carry on. Having a white background can help with the color matching.
No sense in letting the sample sit as it may change color & that just causes confusion.

Yep, don’t over-think it.

 

[DeptOfMeteors]

So you're saying this is all very normal? The colour I get as soon as I do the mix is correct, but after 30 seconds the colour will change and correct results will no longer be available?
Now that I'm able to test the pH, what do you think it should be during this neverending SLAM?

 

[Bperry]

So you're saying this is all very normal? The colour I get as soon as I do the mix is correct, but after 30 seconds the colour will change and correct results will no longer be available?
Now that I'm able to test the pH, what do you think it should be during this neverending SLAM?

I’ve never waited longer for the pH test than it takes to enter the number in my log and then dump the sample. The chlorine test will also change color over time and so can the pH…though I assume much slower.

But you can’t be testing pH while your in a SLAM because it’ll not be accurate and like mentioned above the high FC can goof up the red dye. The pH should be around 7.2 before starting a SLAM because it tends to rise over time and since you can’t measure it during a SLAM, it’s best to lower it so some rise won’t harm anything.

 

[DeptOfMeteors]

And that's what I've gathered from a lot of what I read, but James said the chlorine could be neutralized w/R-0007.

 

[Bperry]

And that's what I've gathered from a lot of what I read, but James said the chlorine could be neutralized w/R-0007.

I’ll let James answer for himself but if you added a drop of 0007 and the result is the same, I’d guess you don’t have an excess chlorine issue and it’s already below 10ppm. But I may be starting to lose track with what’s going on. It’s really hard to debug what’s going on without test data. It’s hard for you and for others. I think it you kept track of test results once a day it’s help figure out what’s going on.

 

[JamesW]

The R-0007 should neutralize excess chlorine.

However, it can change the pH some, so it's mostly to help determine if you have chlorine interference.

Maybe try new reagents.

The pH color might drift up some over 30 minutes, but if it changes a lot in a few minutes to where it goes to a purple, then there is some type of interference, which is almost always due to chlorine.