So I have been playing with the pool water chemistry for about a month now. I have been using the K-1000 OTo for quick testing( comes with the TF-100.) The DPD test question: my 1st time doing this type of testing so forgive my dumb question: when I add the suggested amount of powder the sample turns pink, ok did that right. then I put the drops in and count until it turns clear, ok did that right, But, then a few seconds later it turned pink again??? Do I begin adding drops again and continue counting? Yes i am swirling each drop.
Taylor DPD test question
- Thread starter Ame
- Start date
Hi, Ame,
You have the FAS/DPD test just for clarification.....it's much different than the DPD test.
You should continue adding drops of R-0871 like you have been doing but make sure you continue to add them until their is absolutely no further color change whatsoever. Then subtract the last drop (the one that made NO further color change) from your total to finish the test.
The pink color will always return if allowed to set for a minute or so but it should not be turning back in the "few seconds" you indicate. I might be that you have not added enough drops to take the test to completion.
You have the FAS/DPD test just for clarification.....it's much different than the DPD test.
You should continue adding drops of R-0871 like you have been doing but make sure you continue to add them until their is absolutely no further color change whatsoever. Then subtract the last drop (the one that made NO further color change) from your total to finish the test.
The pink color will always return if allowed to set for a minute or so but it should not be turning back in the "few seconds" you indicate. I might be that you have not added enough drops to take the test to completion.
ok, Yes its the FAS/DPD that comes in the TF-100 kit. Like you said maybe I didnt add enough drops to take the test to completion. Because its only a few seconds not 1-2 minutes.
First it is the FAS-DPD test ... The DPD test is like the OTO test only pink.
Second, normal for the water to turn pink again eventually. But if it is only a couple seconds, I am not sure you are done with the FC portion.
Second, normal for the water to turn pink again eventually. But if it is only a couple seconds, I am not sure you are done with the FC portion.
Sometimes high cc levels can bleed through the fc test like this. Are you measuring cc?
Also, if you're not swirling effectively, the test can react like this. A SpeedStir can help.
Also, if you're not swirling effectively, the test can react like this. A SpeedStir can help.
Great, thanks for info, Im looking now for a speedStir now. That swirling thing may be the issue also. And I did measure CC but not sure how acurrate that was due to my Pink coming back. Will try test again today.
arvil
Well-known member
The speedstir was the second best investment for my pool after the TF test kit itself. I even use it to mix the CYA test, then pour it back into the squirt bottle.
The stir bar will fit through the opening on the squirt bottle, and the bottle fits fine on the speedstir. Save yourself a step.arvil said:
arvil said:
Just be sure to rinse and clean well other cylinders you use, as the CYA residual can interfere with other testing if left behind. Don't ask me how I know...
