Hard water contains high levels of minerals such as copper, manganese, calcium and iron. Every time you wash you hair in hard water, these minerals build up in your hair, making it weak at the roots, dry and frizzy. These minerals, when accumulated over time in your hair, are harmful and can cause hair dryness.
The minerals in hard water also prevent the oil and conditioner to reach your hair properly.
The good news is that once you start using soft water and take good care of your hair, your hair condition can be dramatically improved. Softened water will do wonders to your hair in weeks.
The best solution is to install a water softener in your house, as in that way you can also enjoy the benefits the softened water will bring to your skin, laundry, as well as dramatically improving your plumbing system.
Other solutions include: rinsing your hair in a cider vinegar with water, lemon water, or using olive oil, or baking soda on your hair after washing.
Soft water will also be very good for your skin, as hard water causes dry skin conditions and aggravates eczema. Minerals in hard water cause build up of residue on your skin leading to blocked pores and irritation. Your eyebrows and lashes will be nicer and longer too, as a result of using softened water, as hard water has the same harmful effect on them too.
See this map to find out if the water in your area is hard.