We are currently installing a used 38 x 18' doughboy with 7' deep end. Hoping someone can help as we have currently installed the side rails with pressure pads. The side rails were dug in flush with the ground and cemented in. The bottom rail locators which attach to the bottom rails are about an inch above so the bottom rails sit above the compact dirt by about 1". The pictures in the directions are not clear but I am assuming that the bottom rails should have something solid under them? Can sand be put in? We are putting 1 x1 cement pads under all the vertical end cap joints on the curved ends as well. Hope someone can help!