Salt free conditioners are great alternatives to preventing scale build-up in pipes. A salt free water conditioner doesn't require the use of salt/regenerate, electricity, and drainage. There is some confusion that these conditioners remove "hard water minerals" (i.e. calcium, magnesium) when in fact they don't.
As water enters the water conditioner, hard water minerals attach to the yellow resin beads. These beads "conditions" the minerals in such a way that they become magnetized. Eventually they fall off the resin beads and proceed down the pipes.
As they pass through the pipes, these conditioned magnetized minerals start attracting other hard water minerals and get pulled off the pipes. Eventually, they become larger clusters of hard water minerals that never stick to the pipes and go through your faucets and down the drain.