Efflorescence is ugly, damaging, and extremely hard to remove. And once you think its all gone, it comes right back.
What is efflorescence?
Easily said, efflorescence is salt. The majority of all brick, concrete, and even stucco will have some sort of crystalline (salt) deposit in it. When these material get wet, and being as porous as they are, the salt will eventually rise or evaporate to the surface. This salt residue will eventually build up and harden, becoming ugly and hard to remove.
There are a few ways to remove it. The easiest way is using acid and pressure washing it. Using the wrong type of acid will harm the surface, and to much pressure will either harm your surface or just push more water into the material causing it to come back ten-fold.
Apply the proper acid and let dwell. Sometimes it helps to add a surfactant to keep the liquids from drying so fast. let dwell per instructions on the bottle then pressure wash off. Repeat as needed. Also, make sure you are wearing the proper saftey protection!