We have multiple retaining wall blocks that that were given to us for free. Will I regret using these opposed to just going to get the Pavers most recommend? I live in MN suburbs and a lot of things are closed due to the riots so I’m not sure I’ll be able to get into anything this morning and we are starting this morning. Also what is the easiest way you all have found in ensuring the track remains perfectly circle during install? One last question... we have sand as our base and my husband is insistent that sand is sufficient, im sure it is fine but I worry about lumps and bumps that dirt leaves and algae can settle into to, would you suggest something like insulation board to just keep it smooth? Or will that not help? Thanks!! 
