So my daughters bday is Friday so I bought the 18x48 ultra frame and the $129 saltwater system. I'm a perfectionist and want this thing done right. I've read hundreds of posts and watched quite a few videos. At this point I rented a sod cutter and took off the 20 circle. The soil is very good, very compact underneath. As it stands I'm about 2-2.5 off level across the 20 feet. My plan (at this point) is to order enough sand for a 2-4 inch base the i can use to get the final level. At that point I'm going to cut the 6 inch pieces of treated deck board with the beveled edge and sink them in the leveled sand, positioned with the assembled top. Then I plan to water and tamp the sand, cover it with a hd tarp then set up the pool. Any glaring issues or suggestions for improvement (I've read a lot on styrofoam and it seems smart. I'm just not sure I need it and how to add it to the steps planned. I guess level the sand then put the foam down and recess the wood in the foam)? Thanks in advance!