A treatment system provides treated or softened water to a point of use by
removing at least a portion of any undesirable species contained in water
from a water source. The treatment system can be operated to reduce the
likelihood of formation of any scale that can be generated during normal
operation of an electrochemical device. The formation of scale in the
treatment system, including its wetted components, may be inhibited by
reversing or substituting the flowing liquid having hardness-causing
species with another liquid having a low tendency to produce scale, such
as a low LSI water. Various arrangements of components in the treatment
system can be flushed by directing the valves and the pumps of the system
to displace liquid having hardness-causing species with a liquid that has
little or no tendency to form scale.