Oxidizing Shock Water Testing

[dtarantino]

I typically only use liquid chlorine and float one puck to handle any days I miss adding but recently I ran out of chlorine and Added a bag of chlorine free shock someone gave me to the pool after a heavy load of ppl swam. Even after three days my FC numbers are high and it is showing some CC. Are my readings true or is the chlorine free shock messing with them like i read it does? If it is messing with, them will this go away with time?

Test - FAS DPD
FC - 11ppm
CC - 0.5
PH- 7.5
TA - 65 (low)
CYA - 50

 

[Akathisia]

If it's MPS (potassium monopersulfate) this will read as CC but as far as I know it won't impact FC.

MPS isn't a sanitizer in pools so make sure to use chlorine.
Chemistry of Chloramines - indoor commercial pool

 

[Richard320]

The MPS shock will mess with all the chlorine tests.

It'll take a few days to disappear so you can get an accurate reading. I'd target a few FC higher than normal to allow for that and ignore the CC reading for a week or so.

In the future, don't add anything to the water unless you're sure of what it is and what it will do.

 

[dtarantino]

That's 's everyone. A lesson learned. I was being strict about liquid chlorine as my only sanitizer but my vacation messed with my routine. Back to it.