K-2005 is a DPD test kit. K-2006 is a FAS-DPD test kit.
BIGGGG difference!
DPD you can only test to 15ppm on your chlorine.
FAS-DPD you can test to 50ppm or even 100ppm.
We recommend the K-2006 or K-2006C (more reagents).
However, the Leslie's FAS-DPD Service Test Kit is similar and you can get it instead. It's simply Taylor re-agents in a Leslie's box.
Carl
How often would I see CL, CC or FC, above 15 ppm? I guess if you get a big problem CC could go high, but FC? By the way, what is FAS-DPD; is it an acronym or ?
Last edited by iwannapool; 04-17-2007 at 10:11 AM.
If CC is over 15ppm you have a problem. But FC as high as 25? Sure.
If your stabilizer level (CYA) is over 100, you have to shock by getting FC up to 25ppm. You maintain your pool at something like 12-15ppm (I've forgotten exactly).
Unless you have very low CYA (20 or less) you normally will shock to 15ppm of FC--that's now at the limit of standard DPD kits. Past 15ppm ordinary DPD can bleach out and look like 0 ppm! Use FAS-DPD and you have lots of headroom.
Carl
Here's another reason why:
A friend told me they kept having problems with bleaching of bathing suits and extremely dry skin but with very little chlorine in the pool towards the end of last season. A new bathing suit started to fade in less than a week. They were using a 3" puck feeder and would load it up but keep the dial turned down. He used the DPD test (not FAS-DPD) and wasn't registering any or very little chlorine when he did the test so he kept the feeder turned down to a low setting rather than turn it off or empty it. He knew he needed chlorine and theorized it was "burning off as fast as he could put it in". I brought my (Ben's PS233) test kit over and found he was actually over 30 ppm FC among other issues!All due to an old and in inadequate test kit.
Needless to say, he is using a better test kit (a bootleg clone of mine) and now even the BBB method....
Dave
DPD and FAS-DPD are the reagents used.
DPD is N,N-diethyl-paraphenylenediamine. It is the indicator used to test for clorine (and other halogens) using a color comparator. Most men have difficulties with this test because they cannot differentiate between the shades of red the test produces. The test can bleach out at chlorine levels above 10 ppm (which is not even shock level in most pools!). It is accurate to 1 ppm (IF you can differentiate the different shades of red produced.) It can test both free and total chlorine so combined chlorine can be found by the formula TC-FC=CC
FAS-DPD stands for Ferric Ammonium Sulfate -- N,N-diethyl-paraphenylenediamine
This test does not use a color comparator but is a titration test (like the tests for Total Alkallinity and Calcium Hardness) with a distinct endpoint color change from bright pink to colorless. Even people who are colorblind find this test easy to do. This test will not bleach out at chlorine levels as high as 50 ppm with an precision of as much as .2 ppm. (Comes in handy when you want to try and kill algae and it requires you to keep your FC levels at 15 or 20 ppm!) It test for free chlorine and combined chlorine directly. If you want to know your total chlorine it would be FC+CC=TC.
All things considered the FAS-DPD test is much easier to do and produces much more accurate results and is worth every penny extra it costs!
Retired pool store and commercial pool maintenance guy.
Thanks for all replies. Without an understanding of what's involved with these water tests it's hard to tell what you need and what you don't. Thanks, again.
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