Weather here is moderating a bit temp was around 50 the other day. So decided to take a look at the pool. Pulled back the solid cover and let loose the loop lock at the deep end. WOW just as clear as when i closed it. Just for fun I took a water sample (no ice so its warmed up nicely here in Illinois) and was quite surprised to get a chlorine reading of 8.0! I'm guessing that extra gallon of chlorine at closing put the pool in slam and its lasted all winter. This is the first time in 20 years I've ever had chlorine at opening. I think I could put the robot in and be ready to swim if the water was warm, but Id hate to see that gas bill. All in all I believe its going to be another great season.