Efflorescence occurs when salt is dissolved in water and transported to the surface of the concrete. The salt comes from a range of sources including the water, concrete, soil, etc. There are many methods to removing efflorescence and all depend on the surrounding conditions. Cleaning methods include using a dry brush to remove it, mild cleaning agents and water, power washing and efflorescence cleaners. Once cleaned a concrete sealer such as US SPEC Hydrasheen could be applied to prevent it from reoccurring.