Do not be fooled by water conditioners that claim to soften your water without salt or potassium.  They claim to ‘condition’ the water, implying softened water. 

First off, they are conditioners.  They can make this statement because they are clearly changing the ‘condition’ of the water.  This is typically done by removing the chlorine or sending an electric current through the water. 

But carbon or these other type of devices cannot not remove scale, calcium, limestone, magnesium… To truly remove the hardness minerals that leave deposits on our fixtures and ruin our plumbing.  Ionic exchange, reverse osmosis, nanofiltration are tested and validated methods of removing hardness from the water.