I have been debating back and forth as to go with sand as the base or crushed fine limestone on top of the dirt. I plan on using a 1/2 foam pad with foam coves but just wondered how many people used the limestone then just a pad if it provided enough comfort. I read somewhere that if u use the pad directly on top the sand u risk messing up your sand bed with footprints etc when u have to walk around an install the line. The reason I ask is that I am thinking that the limestone would remain firmer after packing and watering it down plus it is readily available in my area. Oh and obviously I will be levelling the concrete pads in the limestone for the post/supports