1 Scoop or 2 Scoops... that is the question...

[FixItPete]

I just watched the TF Test Kits video for doing a Free Chlorine Test... in that video they show using ONE Scoop of R-0870 for the test. In my Taylor K-2006 it clearly says to use 2 scoops...

I'm filling to the 10ml mark.

What's the scoop? (no pun intended... ok, maybe a pun was intended. LOL).

Thanks!
Pete

 

[YippeeSkippy]

I use one with consistent results. More than that, IMO, is overkill and just causes you to have to buy more sooner.

Yippee :-D

 

[FixItPete]

UGH! SOB! Those people (Taylor) robbed me? What the heck?

 

[Pauls234]

Pete, I wondered the same thing so I tested both ways back to back and got identical (or close enough) results. Since then I just use one kinda heaping spoon.

 

[UnderWaterVanya]

I wonder if there is a way to be more scientific about this.

I have noticed that when I get ready to rinse the cylinder the tap water (or pool water) will immediately turn the sample pink - which tells me that there is still some capacity to react with more FC. Is that a good test?

 

[superman0604]

Using the small spoon shaped end of the dipper, add one heaping dipper, or two level dippers, of R-0870 and swirl to mix. If the sample turns pink for a moment and then turns clear again, or if it turns brown, add another dipper of R-0870. If the sample remains clear the entire time, your FC level is probably zero, however it is best to verify that with an OTO chlorine test, since the FAS-DPD test is prone to the occasional false zero.

The exact amount of R-0870 powder used is not critical. The goal is to add more than you really need rather than using too little. Using too little R-0870 powder can throw off the results of the test. You need to use enough to bind to all of the chlorine that is present. Adding extra, within reason, has no effect. At very high FC levels it is likely that you will need to use more than the normal amount.

 

[anonapersona]

If there is some extra in the bottom of the mixture, then you have more than enough. If it has all dissolved, you cannot be sure if you needed more. My heaping spoons are at least equal to two level spoons. Who cares if I use too much, I worry about it degrading over time from using it too slowly more than I worry about using it up too fast.

 

[jblizzle]

One scoop should be plenty except if you are at shock levels ... in which case you may need 2 scoops.

 

[chem geek]

The exact amount of R-0870 powder used is not critical. The goal is to add more than you really need rather than using too little. Using too little R-0870 powder can throw off the results of the test. You need to use enough to bind to all of the chlorine that is present. Adding extra, within reason, has no effect. At very high FC levels it is likely that you will need to use more than the normal amount.

And even this doesn't have to be the case. You want to add enough so you start to see some pink, but if you have high FC and don't add enough powder, then what happens is that when you add FAS-DPD drops the sample can get more saturated red before it starts to get less saturated on its way to clear. The result should still be accurate because what is being measured is how much FAS needs to be added to react with all the chlorine. The DPD powder is just an indicator dye to indicate the presence of ANY chlorine so that you can detect the transition from very little chlorine left (faint pink) to no chlorine left (clear).