With most ion exchange water softeners, what happens to sodium levels in the finished water?

In the process of ion exchange for water softening, calcium and magnesium ions, which are responsible for water hardness, are exchanged for sodium ions. When water passes through the ion exchange resin, these hard ions are removed and replaced by sodium ions. As a result, the sodium levels in the finished water increase. This is a crucial aspect of water softening technology, as it effectively reduces hardness while introducing more sodium into the water supply.

The other options do not accurately reflect the process. Decreased sodium levels would contradict the function of conventional ion exchange systems, and suggesting that sodium levels stay the same overlooks the fact that sodium ions have been added to replace hardness ions. The idea that sodium is exchanged for copper is also incorrect, as copper is not a part of the common ion exchange process in standard water softeners.