Want to close pool this weekend but tested yesterday after a lot of rain this week and need to shock 1.0 CC. Should I go ahead and shock tonight or wait till Wednesday so I can close this weekend with the shock being done closer to closing or shock tonight? Also have a tear about six inches across in the corner of the vinyl liner. Should I repair when I lower the water before closing. I have Myer cover. Is it necessary to drain the water that gets through the cover during the winter? It's usually quite high when I open but use that water to backwash during opening and I don't need to add. Thanks for any help.