High Free Chlorine

Mkstretch

Active member
May 24, 2020
42
ny
Hi guys! My FC is 8.6 and was wondering if their is anything I should do to lower it back down to 4 or 5? I did turn down my chlorinator a little bit.
maybe I should run the chlorinator longer hours at the lower setting to bring it down?
 

jimbethesda

Gold Supporter
Jul 2, 2018
435
Austin, TX
Hi, and welcome to TFP! How are you testing your water? Pool store and test strips are not accurate. You need a TF-100 or Taylor 2006c test kit.

Assuming your value of 8.6 is correct, in order to say if 8.6 is too high, we need to know what your CYA (stabilizer) is. It’s safe to swim up to SLAM level of FC. See the chart below.

 

Mkstretch

Active member
May 24, 2020
42
ny
Hey Jim! I’m using Taylor 2006. Only thing I couldn’t test was CYA, because I ran out. CYA Should be delivered tomorrow.
 

jimbethesda

Gold Supporter
Jul 2, 2018
435
Austin, TX
Ok gotcha. It was 70 last time.
If you haven’t added any, it won’t be any higher. If you haven’t drained any of your pool, it shouldn’t be much lower. The short answer is given a CYA of 70, you can go lower than 8.6. Just follow this chart.