Description
The exchange process is about the ability of the resin bead to take on one ion while giving up another.
When the resin bead is fully loaded with sodium, it will readily give off the sodium (Na+1) with one positive charge in exchange for calcium (Ca+2) with two positive charges.
When all of the exchange sites are loaded with calcium or magnesium, the resin beads are subjected to a high amount of salt (brine).