First time shocking - question

[lborne]

Ok, between 12 inches of rain, a 6 day vacation where I accidently left the swg setting too low (error while testing settings), and the lawn guy getting fertilizer in the pool, my FC got down to 1. Not sure how long it was at 1, and it could have gone lower, but know it only takes a day or less, so I shocked the pool.

Overnight FC loss was 1.5, but CC was 0. I thought you had to have a CC greater than 0 if you have a overnight FC loss.

 

[JasonLion]

No, there doesn't need to be any CC when you have algae.

 

[lborne]

Thanks Jason. That was not clear, at least to me. As a follow up question... if tonight I'm at shock level - say 28, and tomorrow I measure 26, do I really need to bring it back up to 28, or can I hope that since there was only a 2 FC loss overnight that 26 is probably sufficient to do the job and I can just test again the next night cycle?

 

[JasonLion]

Yes, that would be alright. Relatively small differences, like 26 instead of 28 don't make much difference. You may lose much more chlorine during the day, so you will probably need to add chlorine the next evening.