Move from a soft-water city to Phoenix or Las Vegas and your hair will tell you within a month. It feels heavier. Less shine. Takes more shampoo to lather. Dries differently.
That’s not the climate. That’s the water.
What Hard Water Does to Hair
Dissolved calcium and magnesium bind to proteins on the hair shaft. Over time this creates a mineral film, a coating of calcium deposits on each individual strand. The film weighs hair down, reduces shine, makes texture coarser, and causes scalp buildup that feels like product residue even when you haven’t used any.
Color-treated hair gets the worst of it. The mineral deposits disrupt the hair cuticle, the outer layer that locks color molecules in. Damaged cuticles mean faster color fade. Hairdressers in high-hardness cities like Phoenix and Las Vegas often recommend specific color maintenance products for exactly this reason.
The Test You Can Do Right Now
Fill one bowl with tap water and another with filtered or distilled water. Lather your hands with shampoo in each. The difference in lather quality between hard and soft water is immediate and obvious. The distilled water produces noticeably richer foam.
That lather difference tells you how effectively your shampoo is actually cleaning your hair.
Where the Problem Gets Serious
Most people start noticing effects above 7 gpg. At 15 gpg and above, which is common across Phoenix, Las Vegas, Tucson, and much of Texas, the buildup accumulates fast. People who moved from Boston or Seattle to Phoenix often describe the change as dramatic within the first few weeks.
Cities with particularly hard water: Phoenix averages 15-25 gpg depending on the system and the time of year (Colorado River vs. Salt River blend). Las Vegas runs 14-16 gpg. Salt Lake City is in the 13-16 gpg range. San Antonio runs 14-17 gpg.
If you’re in those ranges and wondering why your hair changed after you moved, now you know.
The Baking Soda Problem
One thing worth addressing: the “no-poo” method that uses baking soda for washing is one of the worst approaches for hard water users.
Baking soda is alkaline. In hard water, it reacts with calcium to form additional mineral deposits rather than cleaning them off. It feels like it’s working because of the scalp sensation, but it’s actually making the mineral buildup worse. If you’ve tried no-poo and your hair got worse instead of better, hard water is likely why.
What Actually Works
Ranked by effectiveness:
A whole-house water softener removes calcium and magnesium from all household water before it reaches the shower. This is the complete solution. Hair feels softer, lathers better, and holds color longer.
A shower head filter with ion exchange media targets the problem at the shower specifically. Less effective than a whole-house softener since you’re only treating one fixture and ion exchange capacity in a shower filter is limited, but it makes a real difference. A reasonable middle step if you’re renting or not ready to commit to a full softener.
A chelating shampoo binds and removes existing mineral deposits from the hair shaft. Malibu C Hard Water Wellness Shampoo and Ion Hard Water Shampoo are the most well-known options. Use once or twice a month to clear buildup. This is treatment, not prevention, so you’ll keep needing it as long as you’re using hard water.
An apple cider vinegar rinse is cheap and effective for ongoing maintenance. One tablespoon diluted in a cup of water, applied after shampooing, rinsed out after a few minutes. The acidity dissolves calcium carbonate. The vinegar smell goes away as the hair dries.
Sulfate-free shampoo forms less soap curd with calcium ions than traditional sodium lauryl sulfate formulas. Switching to sulfate-free reduces how fast buildup accumulates, though it doesn’t prevent it entirely.
Leave-in conditioner provides some barrier against further mineral deposition but doesn’t clear existing buildup. Useful as a supplement, not a primary fix.
The Concrete Move
If you just relocated to a hard-water city and your hair suddenly feels wrong, a chelating shampoo gives you immediate relief while you figure out a longer-term plan. Pair it with a shower filter for ongoing protection.
If you own your home and you’re in an area above 10 gpg, a water softener solves the problem completely, for hair, skin, appliances, and laundry, through one change to the water supply.
For the full picture on how a softener works and what it adds to your water, see how ion exchange water softeners work.