Hey Steve,

I live outside Ft. Worth, TX and we never close our pool either. When my chlorinator stops producing chlorine (water temp less than 50 degrees) and I have little to no chlorine, I just throw in a little shock. I have done that one time this off-season. With that said, I think it is only for piece of mind. Nothing is going to grow in the water at that water temp. You really do not need much chlorine when the temp is so low. I have never used the bleach method. I just make sure I have a few packets of shock on hand primarily for emergencies such as if my chlorinator stops working, etc. Our water has been hovering in the upper 30s to low 50s for 2 months now. Your water temp is probably higher most of the time.

Hope that helps a little.

Mike