I don't understand "shocking"

[avidone1]

My pool balance is pretty good right?

FC- 5
PH - 7.6
TA - 100
CH - 450
CYA - 70

If I keep the numbers at, or close to this level, do I ever need to shock?
If so why?
Won't that drive the FC way high and throw the whole pool out of balance?
Sorry for being such a newb, but my pool suffered some serious low calcium issues last year and so I am determined to stay on top of things.

 

[Richard320]

My pool balance is pretty good right?

FC- 5
PH - 7.6
TA - 100
CH - 450
CYA - 70

If I keep the numbers at, or close to this level, do I ever need to shock?
If so why?
Won't that drive the FC way high and throw the whole pool out of balance?
Sorry for being such a newb, but my pool suffered some serious low calcium issues last year and so I am determined to stay on top of things.

You might.....

With CYA of 70, you never ever want to let FC dip below 5. You're at 5 now. A bunch of dirty kids, a windstorm blowing a bunch of crud in, a really hot day, you run out of bleach, or forget to add one day, any of the above and you're too low on FC. Then the algae and the FC are at a stalemate, unless the same happens again, in which case the algae takes over.

Bump the chlorine to 8 or 9 to buy some room for error.

 

[JasonLion]

If nothing goes wrong, there is no need to shock. You shock to solve a problem, like a pool full of algae or a high CC level.

High FC levels correct themselves fairly quickly in an outdoor pool.