Winterizing/Shock Levels

[dschribs]

I don't have any algae issues in the pool and want to close/Winterize on Saturday. Can I just raise the chlorine up to shock level the day that I am closing the pool or does the shock level need to be maintained for several days prior to closing???

Also, if my CYA is at 40 - where should I be in terms of shock level? The Chlorine/CYA chart shows I should be at 16. Is that an adequate level for closing for the entire Winter as well as undertaking the SLAM process?

Thanks!
Dan

 

[Smykowski]

Shock level is fine, provided the water is cold enough. Algae growth (and thus FC consumption) plummet when the water gets cold, which is why we recommend waiting until the water temp is below 60° before closing.