My run fence is 5 foot tall 2X4 welded wire. I'm planning on running a hotwire around the perimeter of the fence (on the outside). I'm planning on running one wire at approx. 6-8 inches above the ground and was wondering if anyone had any suggestions for the height of a second hotwire? I'm torn between running it about a foot above the first wire or running it about a foot below the top of the fence.