Our above ground pool was part of a total back yard project where we had the whole yard regraded, all grass removed, a Crud ton of dirt removed, and laser leveled professionally. Once all that was done, they marked off the perimeter of the pool site and we planted new grass around it. Because everything was brought down to grade, we don’t have the trench looking thing around the perimeter I’ve seen where people backfill. Do we still need to backfill?