I am replacing my 18’ Intex pool with a 16’ Intex pool in a perfectly level spot. I have 20 x 20’ of really heavy duty Astroturf I want to lay under the pool both for cushion and weed control at the edges. I have a round gorilla pool mat I am going to put on top of that as well. My question is do I still need to put blocks under the posts? The ground is flat and compact from having a pool on it for five years and I would struggle to get the posts in the right place with the hangover from the AstroTurf rugs.