the problem is that if your pool is consuming 5 ppm an hour and you put it at 20 and leave for half the day, then you havent kept it at shock level[/quote:3dkqwbdi]march2012 wrote:[quote:3dkqwbdi] duraleigh wrote: I have seen several posts saying that the shock value suggested is a "minimum". That is incorrect because, by definition, there would then be no maximum. The shock value is a suggested constant. It certainly has some margin on both sides but it should be considered a target at which you should always aim.
I had the same thought as march2012 about the FC dropping below shock level if you had to leave the pool for half the day. Now, I haven't needed to shock since going BBB but I want to make sure that I do it right should the need arise.
1. Is the point that the shock level is a target and not a minimum?
2. In the Pool School article, Shock Your Pool, step 2 states: Add enough chlorine to bring FC up to shock level (or a little higher).
Aside from using extra chlorine, what is the harm in overshooting the target shock level by 10-20% if you must leave the pool unattended for half the day as insurance that the shock level does not drop significantly below the target by the time you can run a follow-up test? Until you get a better idea of how much chlorine is being consumed during the shock process, it seems to me that it makes more sense to err on the side of being slightly above the target (especially if you must leave the pool unattended for several hours) as opposed to risking dropping significantly below the target leading to improper shocking and wasting chlorine. Am I missing something?