When chlorine level will back to normal after shock

[tenax]

i agree..it may throw your ph/alkinity off a bit, but...won't hurt..your call only after heavy rain have i had even that be an issue with my pool.

[Simmons99]

I've had several heavy rains - no cover ever. Swam in the rain - swam after the rain. Didn't really change the chemistry much except decrease the chlorine level.