I have been busy and let my pool go. It got lots of leaves in. When I finally got around to cleaning it, the water was green. It goes down to freezing here at night, then gets into the 40's in the day, so the water is pretty cold. I shocked it last night with what I calculated was the proper amount of bleach, but this morning the water is still green. Maybe I miscalculated something, but before I add more bleach, I would like to know if shocking works differently in cold water.