Potassium Chloride vs. Calcium in Water Softeners

Calcium in water causes spots on faucets.

Potassium chloride is used as a water softener to treat hard water with high calcium concentrations. Calcium is a mineral naturally found in water and can cause scale buildup that shortens the lifespan of hot water heaters and plumbing pipes. Potassium chloride helps soften the water by replacing calcium.

How it Works

A water softener is a piece of equipment attached to plumbing systems. Inside the water softener is a mineral tank filled with negatively charged beads that attract positively charged molecules. This process is known as ion exchange.

Ion Exchange

Ion exchange is a chemical reaction using a solid to exchange ions in a solution. Potassium and calcium are both positively charged. When the calcium-enriched water flows over the potassium chloride beads, calcium will kick the potassium off the chloride because calcium has a stronger positive charge.

Potassium vs. Calcium

Although the calcium in hard water can help dietary needs, it can cause washed clothes to look dirty, deposit scale on appliances and create a soapy film on skin. Using potassium chloride to soften water helps alleviate these problems and improves energy efficiency of appliances by preventing mineral deposits.

References

• The Free Dictionary: Ion Exchange
• Popular Mechanics: How it Works, Water Softener
• Buy Water Now: Hard Water versus Soft Water

Resources

• Lenntech Water Treatment Solutions: Water Softener FAQ's