Dpd powder questions

Aug 3, 2015
17
Plano, Texas
Sorry if this is a repeat question. Still new here and I've searched a few times but can't quite find an answer. This is my first time to do the chlorine drop test but I've had the tf100 test kit for a couple months now. I have two pods of the test powder. One is kind of a light gray/purple color and the other is a little bit lighter. I've read that as long as it still turns the sample pink then it is still good to use. Well I've tried with both containers and it does not turn the water pink but rather a shade of the gray/purple. I still tried adding drops of the reagent and stopped after ten drops because I was not seeing any changes. After a few minutes of sitting it starts to get a slight pink tint but I know that's not accurate. Do I need to get new powder? Can someone guide me in the right direction pretty please!
 
Welcome to TFP :)

You are good, you have a much higher FC than you think, the purple color is around 20 to 50 drops or 15 to 25 FC using the 10ml mark

I hope this helps :)
 
Well I don't think I have that much chlorine because I added bleach a day ago and I know I need to shock. Pool is clear but algae keeps returning on the walls. Sorry which one is the oto test? Is that part of the basic kit in the blue box?

- - - Updated - - -

Thanks Texas splash! That link was very helpful. Now my only question is why is my sample turning just the color of the powder and not pink. Would that be equivalent to having zero chlorine? Or should I still expect it to be clear at zero chlorine even though the powder is that color
 
Generally when there is no chlorine, the water remains clear in the 10 ml sample. In some cases it may get cloudy, or even a quick flash of bright red if some levels are really odd. The OTO is that same glass viewer that you use for the pH. On the left side (CL), add the pool water and reagents to see if it turns shades of yellow or brown. If it stays clear again, you have no chlorine.
 
So clear and pink are the only color options, right?. If the water turns any color other than those is my powder bad? I did that test and there's barely a tint of yellow so I know I'm most likely at zero. So all I'm left wondering is of my gray/purple colored water is an actual result or not
 
If FC is 0 the powder test will not turn pink. It might turn grayish.

Also if you are getting algae you need to SLAM and then maintain to your CYA.
 
I've read that as long as it still turns the sample pink then it is still good to use.
That's pretty much correct.

Your OTO test that you took is really important. It is very dependable and the results of your test indicate that you have some chlorine but not very much.

Do you have a pic of that grey/purple result? Is the Chlorine Only tube nice and clean? Sorry to ask, but you are sure you are using the correct reagents?

That is a very unusual result and I am thinking what may cause that. Let's start with a pic if you can do that.
 
It does sound as though you have next to no chlorine at all in the water. You can do this test .... Add 2 gallons of regular 8.25% Bravo or Great Value bleach to the water and let it mix for about 15 minutes then re-test. Two gallons should take your FC to 10. If you only have one gallon handy, then use that (FC of 5). After mixing for 15 minutes, there should be no doubt ... your color viewer should be yellow and the 10ml sample should be bright Barbie pink.
 

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OK so I added bleach and retested. The water immediately turned dark pink. I followed directions and stopped counting when it returned to the gray color. I think my results are 15 total chlorine. The Oto test (then one paired with the pH test) shows the darkest shade of yellow. So 10. Are these results OK? I guess my baseline is going to be gray instead of clear. image.jpg
 
It seems that depending on where I hold it, theres the slightest pink tint. If I hold it up to light and look straight at it then it's clear gray. When I set it down and look from the side theres seems to be a tint. So now I'm confused this seems like too much guess work! I try adding more drops and it's them same. Clear from one angle, slight pink from another.
 
Yes I did. I should clarify. When I first added the powder to the sample it immediately turned dark magenta pink. Then I added the drops until it was clear gray. The picture I posted was after I completed the test for cc. That is the "after" test picture.
 
In that case you might be okay. This note is from the extended test kit amplification:
In rare cases the sample may turn cloudy. If this happens the test is still valid. You add drops until the sample turns cloudy white, i.e. the red/pink is completely gone, rather than waiting for it to turn clear.

So I'm curious ... what was your FC reading (bright Barbie pink to the clear/cloudy/gray); (i.e. 10ml sample, number of drops divided by 2)?
 
14.5 (29 drops pink to "clear")
This is my first time testing so hoping I will be more confident ad time goes on ��

So am I good to start a slam? The water is clear it's just the green that keeps returning to the walls. That would still call for a slam correct?
 
That's correct - SLAM! There should be NO green ever. I don't recall all of your levels, so just to be sure ..
- Was pH already lowered to about 7.2? If not, let the FC drop to about 8-9, validate/adjust pH to 7.2-ish
- I don't recall your CYA. If it was 30, then your SLAM FC is 12 (see Chlorine/CYA Chart below)

Then continue with everything you see on the SLAM page. Not really sure why the whole grey thing earlier, but as long as you're seeing a good FC color change from bright pink we'll go with that for now. Review the SLAM page once daily just as a reminder of things to do, and most importantly (after you adjust pH0 - maintain that SLAM FC! :)
 

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