We bought a 15x48 Intex pool. And we were planning on putting over our fake grass. (Rental landlord said it is ok). But the grass is sloped gradual down about 4". Looking for the best cost effective and safe way of setting it up. Any ideas. We also have a 14 ft concrete pad but it's bumpy concrete and we would have to add an extra foot and half to fit the pool. Please help.