To soften hard water, a water conditioner should be added to laundry. A water softening system that attaches to the building's water lines is also helpful.
The term hard water is used to describe water that contains calcium and magnesium ions. These ions can lower the effectiveness of laundry detergent when washing clothing and linens. Water softeners and conditioners can change the chemical components of hard water, allowing laundry detergent to work more effectively.
Water conditioners can be purchased in retail outlets such as grocery stores or online. These conditioners are added to the washing machine along with the laundry detergent. Borax crystals, also known as sodium borate, can be added to a load of laundry to soften hard water as well. Some commercial laundry detergents developed specifically for hard water systems contain borax. The sodium contained in borax crystals counteracts the calcium and magnesium.
Another option is to install a water softening system and connect it to the water lines, thereby softening hard water throughout the building. These systems work by replacing calcium and magnesium with sodium. However, this will add sodium to the entire water supply to the building, which means that water coming from the sink that's used for drinking and cooking will contain sodium. For this reason, it's best to check with a doctor if someone in the home is on a low-sodium diet. Water softening systems are usually sold in home improvement stores.