I believe the Mg+ Ca+ have a stronger attraction to the Cl- ions in the salt so when soaked in brine they trade places with the Na+
Beads prefer Mg over Na but Mg prefers Cl over beads. So you can recharge with salt brine.
Or it might just be a concentration thing where Na / Mg ratio wants to be the same in the brine and beads. So you just give a really strong brine and most of the Mg etc leaves the beads.
Beads prefer Mg over Na but Mg prefers Cl over beads. So you can recharge with salt brine.
Or it might just be a concentration thing where Na / Mg ratio wants to be the same in the brine and beads. So you just give a really strong brine and most of the Mg etc leaves the beads.