Chlorine use

[CTpoolman]

Hi, last week i used AA to remove rust stain. Followed up with metal out. Since been using about 80-100 oz of 12.5% chlorine per day plus 2 tabs in floater to maintain 4ppm. I don’t really have a historical usage prior because this is the first year I’m “trying”to get off the tabs. Is this normal chlorine use?

FC. 4
PH. 7.5
ALK. 100
CH. 200
CYA 40.

 

[Texas Splash]

Welcome to TFP! You're going through a lot of FC in your 12K pool. 98 ounces is about 8 ppm of FC in your 12K pool. We typically use 2-4 ppm as a 24 yardstick of consumption, but more if there's a large swim party. I will say though the chlorine might be getting consumed by residual AA.

If not the AA, then it's time to do an Overnight Chlorine Loss Test. I hope you have a TF-100, TF Pro Series, or Taylor K_2006C test kit. At the very least, the FAS-DPD portion of those kits.

 

[CTpoolman]

Thanks and thanks for the reply! I just have a Taylor 1006 kit with DPD. I will upgrade especially as that stops matching at 5ppm. I will do an overnight test tonight. Before we swam yesterday afternoon the chlorine was at 4ppm this morning it was at 2ppm. So I guess that’s not bad but I still have those 2 tabs in there so that’s skewing it I’m sure. Also, when I SLAM the pool is it fine to swim during that time?

 

[reggiehammond]

How are you testing CYA? I don't think the 1004 kit has that...
You may have very little or too much CYA, which can influence amount of FC needed.

 

[CTpoolman]

The local pool store tests that. It’s usually 30 or 40, last test they said 40. Used some tabs to get it to that level

 

[reggiehammond]

Ok - they may be 1% off or 100%, but you don't know unless you can properly self-test.