I have a bestway pro max steel 15'x42". I plan to kill the grass, level the dirt, but then is the fatigue mats at harbor freight or the foam boards a better option? I was thinking I needed to do a 16ft circle just to make sure the pool is not on a ledge but it seems like the 15ft is the top diameter, and the bottom of the pool will fit fine in a 15ft circle? Is this correct? If I do the foam boards it will be the .5 thick https://www.lowes.com/pd/Insulfoam-...ene-Garage-Door-Foam-Board-Insulation/3033278 . It seems the foam boards will be cheaper at 85$ where as the fatigue mats would be 150$. Any advice is greatly appreciated. Also I live in Texas so have to avoid the nut grass. Thanks in advance!