As my pool liner was being installed last year, the installer told me not to be shocked when I turned on the light at night. He stated that the smallest imperfection in the poolcrete will be magnified greatly when the light is turned on. He was right with that statement. I also think darker colored liners make it even worse. Ours has little bumps and valleys just as you say, but I understand that to be the nature of most vinyl liner pools. Disappointed as I was, I've learned to accept it and enjoy the pool.