Okay, 3 years ago I had my pool renovated which included having the pool plaster redone. So for the last three years I have been having an increasing problem with calcium build up. It started with white spots on the pool bottom and walls and has now moved to small rough nodules all over the pool walls. See picture of this years opening. So I had the pool acid washed and polished at which time I found the plaster to be extremely thin and hollow? Again see the attached picture. So my question is has anyone had similiar problems? Should the plaster have been alot thicker? Could there be a problem with the plaster used to do the pool. I have always had the pool water chemistry done but have struggled with the PH being high. Constantly putting muriatic acid in.