I have tried several of the classes and ids from the source to no avail. Please let me know how to add a margin/gap under the slider so the background image shows through. Like the gap/margin between the header image and the nav or the nav and the slider. Thanks.
The slider is located inside the content area which is placed on an even larger element that has the background.
You cannot create transparent area (down to the background of the site) using margins and/or padding. You need to disable the general background first (by leaving the appropriate color field empty in the theme settings).