Once the bottom track is put together we stake everything to the dimensions it is supposed to be. First rule of construction; plumb, level, square. We bring the sand for the pool bottom into the hole and level the patio blocks that go under each upright base. You want the blocks to be sunk into the ground as much as possible. This is why it is very important to get the hole as level as possible. Once the blocks are level the wall is installed into the track. We lay out the uprights and topseat pieces around the pool perimeter for easy access when we need them.