Paver Cleaning Acid Wash
Cleaning effloresence and stains from pavers is easily done using an acid wash which requires only a broom, hydrochloric acid and water.
Use 8 Parts water to 1 part Hydrochloric acid solution, you may have to increase the strength if the marks haven't been removed, the stronger the solution the coarser the paver will become exposing the materials of the paver.
Remember to wear protective clothing and safety glasses and be mindful for the surrounding conditions as the run off can harm plants and contaminate fish ponds and animal food sources.
Follow the instructions as on the container.