In many cases efflorescence is more of an aesthetic issue and tends not to cause major damage. None the less, it should be removed once the water source has been averted. The removal process will range from easy to difficult. The thing I find ironic is that water is often used to wash the efflorescence away. Water was the problem to begin with! If at all possible, try to avoid using water to remove efflorescence. Start with a medium bristle brush and gently brush the salt residue off into a container for disposal. This technique achieved a satisfactory result on the vertical surfaces in my basement as seen above. A damp cloth will work on some surfaces, for efflorescence that is not responding to brushing. This worked well for me on the horizontal concrete.
There are even more aggressive ways of removing efflorescence including detergents and acids. However it is important to weigh the benefits versus the detriments. In general detergents and acids are harmful to the environment and specifically can be damaging to building materials. It is hardly worth the effort of removing the efflorescence with acid, if the acid also removes the surface of the building materials we want to remain. In my opinion, aggressive cleaners are only appropriate when stubborn efflorescence appears on an important character defining feature or if it is causing damage.
