New Pool Install - Very confused

[MaxxFusion]

Ys the sand it for the liner. You want the track directly on the dirt. I was going to used patio stones but decided not to in the end. I couldnt see the realy benefit.

[matt4x4]

on a round pool, there is absolutely no benefit by using patio blocks since there is no downward force on the columns at all.
On an oval pool, there is partial downward force on the columns, I say partial since it's actulally outward, but because of the way everything is connected, it get's transferred to a downward/outward force, so essentially, you want to use patio blocks which are long in one direction (place this direction out from the pool) it will be even harder for the uprights to try and push the patio stone into the ground that way.
I also live in Ontario and did NOT use patio blocks on my round pool, my one neighbour has an oval with butresses, also didn't use them, neither of us have problems with the pools.
I placed my sand in the center as mentioned prior, but I also placed a 2-4" thick ring of screenings (crusher run) around the perimeter where the wall sits, approx 1' into the pool and 2' outside of the pool, this was compacted with a rented compactor. This stuff basically sets up rock hard and provides a great base for teh wall, it also raises your wall off the ground so when you spread out your sand at 2-3" thick, you do not lose any depth in the pool since your wall was built on higher ground so to say.