I have finally got my int. mist system altogether(plan to prop. a bunch of wichita blue's for a hedge row, creping juniper, some crape myrtles, and maybe a few other species for my own use. I live in zone 7(virginia beach virginia)I am starting to second guess part of my design - most of it is built from scrap's etc - its 4 foot x 8 foot(10 inch tall press. treated lumber), and has 35" tall removable plexiglas sections to keep the wind from affecting the water(on all 4 sides). It is outside and I'm using coarse sand as the medium. My question is - should I cover the top for shade? should I try to cover w/ plastic to keep the humidity? I have a decent control system and could literaly program just about any schedule to keep fresh cool water on the cuttings(down to a few seconds evry minute, or just teh standard 10 seconds every 10 minutes). Any help in what to do w/ the roof of this box is appreciated(cover for shade, cover and seal for humidity, mist more frequently and leave open...) . I was hoping to start next week(temps in the 70's, but can get in the 90's quick). Thanks