I just got the Taylor FAS-DPD test kit. I already have a regular Taylor DPD test kit (chemicals are a few months old). My target FC level is 6 ppm (I have a SWG with 80 ppm CYA).
First I measured the chlorine with the regular DPD kit. Because it measures 0-5 ppm, I diluted the pool sample 1:1. I measured exactly 2 ppm FC. In the 1-3 ppm range it's pretty easy to match the colors, so I'm pretty confident in this number.
Then I measured with the FAS-DPD kit. Using the .2 ppm resolution I got 6.8 ppm FC. Using the .5 ppm resolution I got 7.5 ppm FC. Any idea why I'm seeing such a huge difference between the regular DPD kit, and the FAS-DPD kit?