Taylor K2006 FC Testing

[PebblePool]

OK, so I have a Taylor K2006 test kit. I've never done DPD testing, always just OTO testing off a cheapie kit that I bought from a Big Box store.

Sooo,
My OTO test says 2ppm FC.
My Pool Store (I know) says 5ppm FC
My test is 9ppm FC.

I am figuring that the pool store just quit dropping at 5ppm to save on reagents. Here is how I tested it.
1) I filled the comparator to 10mL
2) Added 1 dipper of the DPD powder (turned pink immediately)
3) Added 18 drops of the first reagent swirling after each drop until it turned clear.

Any thoughts?

 

[JoyfulNoise]

Your FC is 9ppm. However, you should consider buying a SpeedStir, it makes testing faster, easier and slightly more accurate (not a huge amount but hand swirling can be a drop or two different from using the SpeedStir).

OTO is useless as a diagnostic test. It is merely a "presence of chlorine" test. In my years of using both OTO and DPD-FAS testing, I could never get the yellow OTO to ever be close to the DPD test. Even the DPD-only pink color comparison test (K-1001 test kit) is more reliable than the OTO test.

No one here bothers putting any credence in pool store testing.

 

[PebblePool]

Yeah, it seems like the pool store is just trying to have me overshoot the chemistry. Right now, I have the following numbers

FC 9
pH 7.4
TA 80
CH 280
CYA 30

The pool is clear as can be, I am keeping my CYA on the low end of the range because I am chlorinating using my residual hockey pucks until I can put salt in my pool finish 60 days post Pebble-Tec installation.

Your FC is 9ppm. However, you should consider buying a SpeedStir, it makes testing faster, easier and slightly more accurate (not a huge amount but hand swirling can be a drop or two different from using the SpeedStir).

OTO is useless as a diagnostic test. It is merely a "presence of chlorine" test. In my years of using both OTO and DPD-FAS testing, I could never get the yellow OTO to ever be close to the DPD test. Even the DPD-only pink color comparison test (K-1001 test kit) is more reliable than the OTO test.

No one here bothers putting any credence in pool store testing.

 

[xyz]

You can do 25 ml and get 2.5x the accuracy if you like. Then it is 0.2 FC per drop. I like it because I get more accurate CC measurement, if/when I think I might have an issue with CC.