Hello.  We installed our fiberglass pool and spa in 2015.  From the start the spillway has experienced backsplash, causing the tiles and coping to be constantly wet and develop green and black mold. Last year, I attempted to clean them and noticed that the tiles were very loose just under the spillway as well as the spillway tiles themselves. The contractor used silicone to attach the tiles and it was easy to remove them and take up the moldy silicone underneath.  When I did that I noticed that the spillway "wall" is not square. It is curved. There is a "ton" of silicone in the gap between the spillway tiles and the fiberglass wall.  The tiles are broken and need to be replaced but I don't want to use the same method that the contractor did. I've found a better adhesive that should bond to the fiberglass but I'm looking for recommendations on how to install tile on the curved surface of the spillway rather than just building up a silicone "bed" for a flat tile to lay on.  Any advice I can get would be appreciated.