I have been told on here before it is safe to swim UP to shock level. I have been shocking this past week so my level is at 30 right now (I shocked high because I think it was mustard algae)so do we go by the normal shock number? A normal shock level would be 21 for my numbers, so I should not get into the pool until it is 21 or below correct? I really need to vacuum and it is so much easier being in the pool doing it than outside of it...Thanks!