We just had a 20x40 inground liner pool installed in the fall. We have 7.5 feet of concrete on both long sides with 10 foot on each end. On one side of the deep end, our concrete has cracked separated and dipped in that area. Before we removed the winter cover, we had a concrete/foundation specialist come out and take a look. He says we could inject some of the leveling foam under the sunken area and that would do it. A few days after, our pool guy came over to open our pool. They removed the cover and dumped some chemicals and left. Our water level was a little low, so we had to add more water. He told us where on the skimmer we should raise the water level, but the more water we added, the more I noticed that the water didn't hit the liner evenly around the pool, mainly on the cracked concrete side. I measured and on the good side with the skimmer, the water was about 7 inches from the coping and on the bad/cracked side we were about 5 inches from the coping. My question is, would just a cracked/sagging pool deck cause the water level to be different? Would foam fix the problem? Or could it be that the footer for the pool wall has shifted? I have a couple of pictures from a distance the crack is on the far left side. I will post more of the actual crack a little later.