K1000 results higher than FAS/DPD

Smelscifi

Active member
Jan 7, 2020
39
Houston
When I tested my pool today, visually the K1000 looked to be in the 5-10 ppm range. When I checked it using FAS/DPD, it only came out to 3.5 ppm. The discrepancy is pretty troubling to me since I was planning on using the K1000 as my daily test once I got the level below 5 ppm. Any advice?

For reference, CYA tested at 50 ppm- I’m in the process of boosting this up to 80 (sock in the skimmer) which I hear can make the K1000 even less reliable. Is the K1000 just not good for SWG pools? Am I stuck running the FAS/DPD daily/weekly?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
17,995
Northern NJ
K-1000 chlorine test is basically a binary test telling you if you have chlorine in your pool or not. As you are seeing it is very inaccurate.

Once you get your SWG dialed in you can use the K-1000 to confirm your SWG is still putting out chlorine. But to adjust your SWG up or down by a few ppm you need the FAS-DPD test.