How long can FC be below the minimum level?

[JMPool99]

I was gone a couple days and we had some intense UV and a lot of debris drom
Some winds. I thought I added enough chlorine but under did it. Upon returning my FC was below the recommended minimum in Pool Math. My recommended is 7.0 - 12.0 because my CYA is 85. Anyway, FC was at 4.5 for about a full 24 hours and prob below 7 (the min) for 18 hours. No one swam in it.

I’m just curious how long it takes problems to start if you’re below the min FC.

THANKS

 

[mknauss]

Minutes to weeks. Raise the FC back to target. Do an Overnight Chlorine Loss Test

 

[JMPool99]

Good call.

My normal overnight is about 1.0. When I have debris and winds sometimes 1.5+ overnight.

Will monitor!