I have stacked stone around my raised spa BUT ONLY on the exterior deck side. The spa wall that faces the pool and has the spillway is tiled with the same waterline tiles as the pool. Pool water can cause calcium deposits and efflorescences. Stacked stone all the way around the spa with an active spillway can get quite messy with white calcium deposits as the years go and difficult to clean with standard acid etching. I would suggest you consider tiling the part of the spa that faces the pool for easy cleaning.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006