What does sodium in water mean in practice?
Sodium is a dissolved cation that affects salinity and increases after sodium softening in proportion to the hardness removed.
When does it matter?
It does not form typical scale, but its level may be important for taste, processes and people following a low-sodium diet.
Which solutions are related to it?
It is determined in the laboratory, the change after softening is calculated and RO is reduced if necessary.