We had our intex set up by a pool installer. They used vermiculite and packed that down and then laid sheet foam insulation duct taped together over that then a thin piece of rolled foam. Intex went on top. They used patio blocks under the feet and many broke. I'd suggest using wood instead. It is less likely to break than the patio blocks. Make sure it's about 12" wide as the legs will shift when you fill the pool. After we filled it we back filled around the pool and over the vermiculite with pea gravel. Add stepping stones and instant backyard oasis!

Here's a link to the photos of our setup. https://suzyabbott.shutterfly.com/65