Can Hard Water Cause Acne? Protection & Solution 2024

Acne is one of the most common skin conditions in the world, affecting around 85% of people at some point between the ages of 12 and 24. However, acne doesn’t only affect teenagers – around 40-50 million Americans over the age of 25 also deal with adult acne. With acne being so widespread, people are constantly on the search for potential causes and solutions. One possible acne culprit that has been getting some buzz recently is hard water. But is there any truth to the claim that hard water can trigger breakouts? Let’s take a detailed look at the evidence.

What is Hard Water?

Before examining if hard water contributes to acne, it’s helpful to understand exactly what hard water is. Hard water contains a high concentration of dissolved minerals, specifically calcium and magnesium ions. These metallic ions make their way into water as it flows through soil and rock formations that are rich in calcium and magnesium.

The level of hardness is determined by the concentration of these minerals and is typically measured in units of milligrams per liter (mg/L) of calcium carbonate. The classification scale is as follows:

  • Soft water: less than 60 mg/L
  • Moderately hard water:61-120 mg/L
  • Hard water:121-180 mg/L
  • Very hard water: over 180 mg/L

The higher the number, the more minerals are present and the “harder” the water is considered. The minerals that make water hard do not pose any health risks and are generally safe to drink. Hard water is sometimes considered preferable to soft water because it provides trace amounts of calcium and magnesium which are beneficial minerals.

However, hard water can cause some aesthetic and functional problems. The excess minerals bind to soap molecules, which makes it harder for soap to lather properly. Hard water also leaves behind mineral deposits on everything it touches – including your skin. This is why the potential link between hard water and acne exists.

Exploring the Hard Water and Acne Connection

So how exactly could hard water contribute to breakouts? There are a few ways the minerals in hard water could theoretically worsen acne:

  1. Hard Water Forms a Film on the Skin

When hard water evaporates, it leaves behind a thin film of minerals on the skin. This film can clog pores, trap bacteria, and promote inflammation – all factors that stoke acne formation. Dermatologists sometimes refer to this film as a microscopic layer of “limescale”.

Some research suggests that this mineral film alters the skin’s pH and disrupts the protective barrier function of the stratum corneum (the outermost layer of skin). This perturbation allows irritants, bacteria, and inflammation to penetrate deep into pores and provoke pimples.

  1. Hard Water Interferes with Cleansers

Hard water makes it difficult to properly cleanse skin because it diminishes the effectiveness of soaps and cleansers. The minerals in hard water bind to the fatty acids used to make soap, forming an insoluble scum that sticks to the skin. This scum hinders soaps and cleansers from washing away dirt, oil, and impurities.

When skin isn’t thoroughly cleansed, pore-clogging debris remains on the skin and can worsen acne. Additionally, the film of scum left behind by hard water may physically obstruct pores and cause further congestion. Dermatologists sometimes refer to this gunk as a “soap scum film.”

  1. Hard Water Can Irritate Skin

For some individuals, the minerals in hard water can be irritating to facial skin and provoke inflammation. This irritation may manifest in redness, dryness, tightness, stinging, and sensitivity. These are all signs that the skin barrier has been disrupted.

This type of skin irritation is considered sub-clinical inflammation because it’s mild and doesn’t present with major symptoms like pustules or cysts. However, even minor irritation and inflammation can be enough to trigger breakouts in acne-prone skin.

  1. Hard Water Alters the Skin Microbiome

Early research indicates that hard water may alter the delicate balance of bacteria on the skin (known as the microbiome). A 2013 study found that hard water shifted the diversity of microbial communities on skin, favoring microbes associated with eczema and acne.

Additional research is warranted to better understand how hard water impacts the billions of microorganisms inhabiting our skin. But if hard water does dysregulate the microbiome, this could potentially promote acne.

Scientific Research Evaluating the Link

The above mechanisms provide a theoretical rationale for why hard water could worsen acne in some people. But does the scientific evidence support a causal relationship between hard water and breakouts? Let’s review what the research has uncovered so far.

Observational Studies

Some observational studies have found associations between exposure to hard water and increased acne severity or prevalence.

A 2006 study followed over 3,000 adolescent girls in the UK and found that those living in hard water areas were 22% more likely to seek medical treatment for acne. A 2010 study in the U.S. evaluated over 2,000 participants and also observed a correlation between hard water exposure and moderate to severe acne.

However, these types of observational studies can only detect correlations and cannot prove cause and effect. More robust clinical trials are needed to determine if hard water definitively worsens acne.

Intervention Studies

Intervention studies that actively manipulate hard water exposure provide more compelling evidence than observational studies. However, only a handful of small intervention studies exist so far.

Short-Term Studies

A pair of one-week studies conducted in the 1980s hinted that showering with hard water worsened acne compared to soft water:

  • In a 1983 study of 22 participants, showering with hard water for one week increased mean acne lesion counts by 21% while showering with soft water decreased lesions by 18%.
  • A 1989 study of 47 teenagers found that using hard water for face washing increased acne severity grades by 11% on average compared to using soft water.

While intriguing, both of these short-term studies had methodological limitations like small sample sizes.

Longer-Term Studies

More recently, a 2019 study followed 36 acne-prone males aged 18-30 years for six weeks. The participants were split into two groups:

  • Hard water group – bathed with untreated hard water (~300 mg/L hardness)
  • Soft water group – bathed with ion-exchanged soft water (~1 mg/L hardness)

Acne lesion counts were monitored weekly along with sebum production levels.

By the end of the six weeks, the hard water group experienced a 3-fold greater increase in total acne lesions compared to the soft water group. Sebum production also increased to a greater extent in the hard water group.

This robust 6-week trial offers the strongest evidence yet that long-term use of hard water can aggravate acne in some people. But larger scale, multi-center trials are still needed to fully confirm the relationship.

Tips to Prevent Hard Water Acne

While more research is still underway, the current evidence suggests hard water may contribute to acne breakouts – especially in acne-prone individuals. Implementing the tips below can help reduce the likelihood that your hard water will worsen your acne:

  • Install a water softener system – This is the best solution as it will convert your entire water supply to soft water and prevent mineral buildup.
  • Use a shower/faucet filter – An affordable alternative is to install filters on your showerhead and bathroom faucets. Look for filters that specifically reduce calcium and magnesium.
  • Wash with soft water – If you can’t filter all your water, at least wash your face with softened bottled water. This ensures cleansers can work properly.
  • Exfoliate regularly – Use a facial scrub 2-3 times per week to remove any mineral deposits and buildup from your skin’s surface.
  • Moisturize after washing – Applying moisturizer creates a protective barrier that can prevent irritation from hard water.
  • Use gel/foaming cleansers – These don’t form scum like bar soaps and are better suited for washing with hard water.
  • Rinse thoroughly – Take the extra time to rinse your face very thoroughly after cleansing to wash away all traces of product, dirt, and minerals.
  • Pat skin dry – Be extra gentle when drying your skin after washing. Rubbing with a towel can damage the skin barrier.
  • Avoid long, hot showers – Limit showers to 5-10 minutes and use lukewarm water rather than scalding hot water which is drying.

FAQs About Hard Water and Acne

Still, I have some lingering questions about the relationship between hard water and breakouts. Here are answers to some frequently asked questions:

Can I get a water test kit to check my home’s hardness?

Yes, water testing kits are readily available from most hardware stores, online retailers, and water filtration companies. These kits allow you to measure the hardness of your tap water right at home. Most kits are easy to use – filling a vial with water, adding a testing tablet, and comparing the color change to a scale.

What level of water hardness starts to affect acne?

There isn’t a precise cutoff, but most dermatologists agree that water over 120-150 mg/L calcium carbonate hardness can begin causing acne issues in susceptible individuals. Again, this depends on your sensitivity as some people have no problems even with very hard water.

Is it okay to wash my face with hard water sometimes?

Occasional exposure to hard water, like when traveling, likely won’t cause major breakouts. However, repeated long-term use of untreated hard water raises the risk for acne problems. If you have severe acne, it’s best to stick to washing with soft water whenever possible.

Can swimming in pools or the ocean worsen acne?

Yes, swimming in any kind of mineral-rich salt or chlorinated water can potentially aggravate breakouts. The minerals can build up on your skin just like hard water. Be sure to shower and cleanse thoroughly after swimming to remove any irritation.

Does boiling or filtering hard water make it better for your skin?

Boiling doesn’t remove the dissolved calcium and magnesium that causes hardness, so it won’t make hard water any gentler on your skin. Filtering hard water is effective – but the filter must be specifically designed to remove minerals. Not all water filters are formulated for that purpose.

Can hard water cause other skin issues besides acne?

Yes, hard water has been implicated in multiple dermatological issues beyond just acne. Hard water may exacerbate eczema, trigger sensitive skin reactions, contribute to dryness and irritation, worsen some cases of rosacea, and make rashes like poison ivy more bothersome.

Any condition worsened by skin irritation or inflammation may potentially be aggravated by hard water. Individuals with chronic skin conditions should take extra care to minimize hard water exposure.

If I have hard well water, is there anything I can do besides installing a softener?

If a full home water softener isn’t feasible, try these alternative solutions:

  • Use a showerhead filter and sink faucet filters to soften your bathing and face washing water.
  • Fill jugs with distilled or filtered water just for face-washing purposes.
  • Use bottled soft water occasionally as a short-term solution.
  • Use liquid facial soaps instead of bar soaps which bind to hard water minerals.
  • Upgrade to an advanced reverse osmosis system for the most thorough filtering of well water.


Based on the available scientific research, it appears that prolonged use of hard water may exacerbate acne breakouts – especially in those already prone to acne. The mineral deposits left behind by hard water can clog pores, irritate the skin, interfere with proper cleansing, and disrupt the normal microbiome.

However, more large-scale clinical trials are still needed to firmly establish hard water as a causative acne trigger. For now, individuals concerned with hard water-related breakouts should take proactive steps to minimize mineral exposure like installing water softeners, using microfiber filters, washing with bottled soft water, moisturizing diligently, and exfoliating regularly.

With prudent avoidance measures, those cursed with both hard water and acne may be able to enjoy clear skin after all. But we will have to wait for the definitive verdict from ongoing research initiatives seeking to unravel the precise relationship between hard water and breakouts.


The article is for informational and educational purposes only. It is not intended as medical advice. Please consult a medical professional for personalized recommendations.

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