Increasing free chlorine?

[Pdp]

Ic40 is set to 0. Have added liquid chlorine as needed.

17 days ago, added 97oz to bring up fc.

Haven’t added any since. Subsequent testing on different days has shown drop to 6.5fc.

I added salt, brought level up to 3200 for the first time. Haven’t added any chlorine since.

8 days ago tested at 9ppm, today at 12.5. I’m pretty confident in my testing and it seems to match up with the “easy” test that’s combined with the ph test. I always test with the drop test in the big kit, not the simple “match the yellows” test.
Any ideas what’s going on? Water Temps have been 52-55. It seems like the swcg may be producing a little bit but the red off/cold light has been steady every time I’ve checked.

 

[mknauss]

FC only increases if you add chlorine. So you have added chlorine or it is testing error.

 

[Pdp]

Yes so I understand… I’ll go meticulous recheck in a few minutes… I’m wondering if my swcg isn’t actually off?

 

[Pdp]

I’ve just run the drop test 3 times. The only thing I can think is that I’ve been inconsistent with my 10ml measurement. Slight variation, but within 1.5 ppm. I’ll keep checking and adding nothing meanwhile. I have a short trip and will test again on Christmas Eve.