Chlorine level increases as it sits??

[gingern]

I use the TF-100 test kit. Whenever I am testing for chlorine, whether it's free or total, I have noticed that as it sits it reads a higher level. In other words, when I first drop the 5 drops of test in the tube it is pale yellow, within as little as 10-15 seconds it is brighter yellow (or, is already reading a whole point higher). Same with the pink of the free chlorine. I could add a few drops of the test and it turns clear and stays that way for many seconds after swirling, then I look back at it a minute or so later and it's bright pink.

So, my question is, when is the best time to record the correct reading for chlorine? The second I am done swirling the test tube, or 10 seconds later, 20...???

Thank you!

PS. I use a salt water system, but shock and increase with bleach.

 

[jblizzle]

With the OTO test, a darkening points to the presence of CC.

For the FAS-DPD, add drops until it is clear and you are done with FC, then immediately do the CC test. It will always go back to pink if it sits.

 

[bobodaclown]

Something doesn't sound right.
Pale yellow isn't a normal color. Here's the video on the test: FAS/DPD Chlorine test for the TF-100 - YouTube

Here's all the test videos: https://www.youtube.com/playlist?list=PLE98E18E2EE701C4D

 

[gingern]

Something doesn't sound right.
Pale yellow isn't a normal color. Here's the video on the test: FAS/DPD Chlorine test for the TF-100 - YouTube[/url

My question is in regards to two different chlorine tests. When I was referring to the pale yellow, I was speaking about the total chlorine... the one that uses the R-0600 drops. I know the pale yellow still indicates a problem... too low of chlorine. I am currently working on SLAMing my pool from opening it up for the first time this year.

Back to my question... When I read the results of the chlorine (the total chlorine with the R-0600 drops) should I read the immediate results... like, just a second or so after swirling? Or, should I wait 10 seconds or more????

 

[Patrick_B]

Read upon swirling. Don't wait ten seconds.

 

[gingern]

With the OTO test, a darkening points to the presence of CC.

For the FAS-DPD, add drops until it is clear and you are done with FC, then immediately do the CC test. It will always go back to pink if it sits.

Got it! Thank you. As you can see (or may have guessed) I am opening my pool for the first time this year, and it needs to be SLAMed.

- - - Updated - - -

Read upon swirling. Don't wait ten seconds.

Perfect! Thank you again!

 

[Patrick_B]

That's ok, you are on the right track, and all the help you need is here. Good luck on it, you'll be very pleased when it's done.

 

[jblizzle]

Or just skip the OTO test and stick with the FAS-DPD for now.

 

[bobodaclown]

Sorry I've only used the FAS-DPD test never the OTO.