It is 2021, so I’m not sure if anyone is still reading this forum. I had my pool resurfaced with pebbletec. The contractor did an acid wash 48 hours after applying the surface. He did not expose all of the pebbles, so it looks like I have patches of concrete all over. I complained. They had me drain it, came back and acid washed it again. It is much better but there are still large area where the “plaster-concrete” (I’m not sure what the pebble is set in) was not removed. I really don’t want to drain my pool a 3rd time. Does anyone know if a no drain acid procedure will remove the concrete over the pebbles, or does it only work on calcium.? Thank you for any information. 
