I am at a loss. Setting up a new pool. I measured each spot with the string level where the pool legs are going to be. I kept one rod over one leg (reading like a clock the 12 position) and measured directly across the pool( 6 position) and leveled that first. then did the remaining leg spots to that position 12 leg. They all measured perfect. I then moved both rods to the 3-9 position and 1 side was almost 2 inches higher. I don’t know why? Is there another way I should have used the string level? Each leg spot measured level to the 1 leg but not directly across from each other. How can that be?