Why is my pool eating chlorine?

[CapeCoral]

The pool got a little cloudy and I thought my salt cell was not producing well. My other numbers are ok (pH 7.5, TA 110, CH 300, CYA 60.) I tried SLAMming the pool the past couple of days and I hosed down the cartridge filter. Phosphate test strip showed nothing. The pool looks great - crystal clear. CC is 0.5. But overnight again chlorine went from 28 to 21 (I did have a few people in the pool before I tested before bed.) What am I missing??

 

[ajw22]

Welcome to TFP.

It sounds like you have not followed the SLAM Process step by step with no shortcuts until you meet the three exit criteria.

Follow it.

 

[Bperry]

The pool got a little cloudy and I thought my salt cell was not producing well. My other numbers are ok (pH 7.5, TA 110, CH 300, CYA 60.) I tried SLAMming the pool the past couple of days and I hosed down the cartridge filter. Phosphate test strip showed nothing. The pool looks great - crystal clear. CC is 0.5. But overnight again chlorine went from 28 to 21 (I did have a few people in the pool before I tested before bed.) What am I missing??View attachment 644982

FC of 28 is pretty far over the SLAM level of 24. Don’t have people swimming in that. The OCLT also tends not to work as well when the FC is over SLAM level. Try again when it’s back in normal range and no one is swimming.