Angie's LIST Guide to
Water softeners

Calcium and magnesium leach back out of the water wherever it constantly flows, so you’ll see a yellow-white crust forming on faucets, around pipe joins and inside of your coffeemaker and dishwasher. You can use white vinegar periodically to clean these appliances, but the buildup will come back.

Minerals in water also tend to bond with the molecules in soap, producing a scum-like substance sometimes called “soap curd” that builds up on shower curtains and leaves a film on glassware in the dishwasher. This chemical bonding also reduces the amount of soap molecules available to form a lather – which means you have to use more soap to get the job done.

In high school chemistry class, you learned that elements can have positive or negative charges, and molecules are formed based on those attractions.

For example, Hydrogen has one positive charge while Oxygen has two negative charges. That’s why water molecules (H2O) are made of two Hydrogen atoms and one Oxygen atom. Calcium and Magnesium each have positive charges, so water "softeners" were designed to use a negative chemical attraction to snatch these positive elements out of the water.

Usually, this is accomplished by the use of a network of negatively-charged plastic beads through which the water passes. The beads are coated with sodium ions that have a single positive charge, so they are easily displaced by the Calcium and Magnesium ions that each have two positive charges. The calcium and magnesium ions cling to the beads, exchanging places with the sodium ions that are carried off by the water.

Eventually, the beads have no more sodium to exchange and the softening process stops working. This is why your water softener is set to “recharge” overnight. Brine water from the salt tank washes over the beads. The mineral deposits are washed down the drain, and the beads are resupplied with sodium ions for another day.

If you want to switch to potassium chloride pellets instead of salt pellets for your water softer, you can do so easily. No change to your equipment is needed. You can simply buy the alternative pellets and refill your water softener tank as normal.

The main reason for doing so would be to eliminate the presence of sodium in your tap water. However, using potassium chloride pellets generally costs about three times as much as salt. Bags of potassium chloride pellets may be a little harder to find, but major hardware stores typically carry them.