Now What? Sand/pool?

In order to level the ground underneath a new above ground pool, I had sand brought in & leveled it off. I placed landscap-ing bricks at low end to retain the sand. Now I learn that the mfgr. DOES NOT recommend using sand underneath, because of its instability. Do you have any recomendations? I do not want to go thru removing the sand. The pool is a 12' dia. I have thought of placing plywood on top of sand, but that really doesn't seem right either. I certainly don't want to make concrete using the sand either. Help please. The sand on low end is about 8" deep & approx. 2" deep on shallow end.