The first community-powered water map for Asians living abroad. Test your tap, get your Water Report™, and put your city on the map. 🗺️✨
Why this matters
Frizz out of nowhere. Color that fades in weeks. A scalp that never feels clean. If your hair changed when you moved abroad, it may not be your shampoo — it may be your water. 🚿
Tap water varies enormously from city to city. Minerals like calcium and magnesium build up on hair over time, and Asian hair — often thicker, straighter, and more frequently chemically treated — shows the effects in its own way.
The HAO Global Hard Water Project™ maps how local water behaves, city by city, so you can care for your hair with evidence instead of guesswork. ✨
The science
Three things in your wash water shape how your hair behaves — and each works differently. This is what your HAO Water Kit™ measures, and why.
Minerals · measured as Hardness
Hard water carries dissolved calcium and magnesium. When they meet shampoo, they form a film that clings to hair and scalp — a bit like a thin layer of wax. Over time that film blocks water and conditioner from getting into the hair, so hair feels dry, heavy, and dull, loses its shine, and scalps can feel itchy or flaky.
pH · measured as Water balance
Healthy hair and scalp sit slightly acidic, around pH 4.5–5.5. When wash water is more alkaline than that, the hair's outer protective layer — the cuticle — lifts. Lifted cuticles catch on each other, so hair tangles more, loses moisture and protein faster, splits and breaks more easily, and lets color wash out sooner.
Chlorine · measured as Free chlorine
Tap water is disinfected with chlorine, and the residue that reaches your shower is an oxidizer. It strips the natural oils your scalp produces to protect hair and can weaken the hair's protein structure — hair feels straw-dry, colored hair fades faster, and sensitive scalps may feel tight or itchy.
✨ Why we measure all three
When all three run high at once, they compound: an opened cuticle lets minerals lodge deeper, while stripped oils leave nothing protecting the surface. That is why the same hair can behave so differently from one city to the next — and why we measure all three together, not just one.
The usual counters, if your readings run high: a chelating shampoo for minerals 🧴, a shower filter with a chlorine cartridge 🚿, and moisture or bond-repair care afterward 💆. Your Water Report™ matches these to your actual readings. Cosmetic hair-care effects only — not a water-safety assessment.
Curated products · Editor's picks
Each of the three things we measure — minerals, pH, and chlorine — has a counter. A chelating shampoo for buildup, a shower filter for chlorine, and a softener for the whole home. Your Water Report™ matches these to your actual readings.
Rescue · Chelating shampoo
Lifts mineral buildup so hair can breathe again.
Chelating shampoo
The anchor product for hard-water cities like Los Angeles — start here before adding a filter.
Filter · Shower head
Cuts chlorine and sediment before it touches your scalp.
Inline shower filter
The #1 easy-conversion product from the Water Report — recommend when a softener isn't feasible.
Fix · Whole-home softener
Treats hard water at the source for the whole household.
Ion-exchange water softener
The gold-standard end-state solution — the 'fix the source' answer on the education page.
Cosmetic hair-care effects only — not a water-safety assessment. Product picks are editorial and may include affiliate links.
Five steps
Request or pick up a HAO Water Kit™
Test your tap water
Scan the QR code on your kit
Upload your result
Receive your Water Report™
The kit
Dissolved calcium and magnesium — the main cause of mineral buildup on hair.
How acidic or alkaline your water is — alkaline water lifts the hair's cuticle.
The disinfectant residue in tap water — it strips the natural oils that protect hair.
✨ Heads up: pH and hardness measure different things. Hard water is about minerals, not acidity — we measure both because each affects hair differently. Optional test-strip photos help us verify readings.
Future rounds: TDS and more. 🔭
Live data
Softer back home 🏙️ vs harder abroad — feel the difference.
estimated from public data unless marked 🧪
🌏 16 cities on the map · 100+ community tests so far — add yours and get ahead 💧
💧 Test my water📍 Irvine
California, United States
Updated 7/12/2026
📍 Costa Mesa
California, United States
Updated 7/22/2026
📍 Irvine
California, United States
Updated 7/12/2026
📍 Los Angeles
California, United States
Updated 7/12/2026
📍 Los Angeles
California, United States
Updated 7/24/2026
📍 Rowland Heights
California, United States
Updated 7/19/2026
Your grade
One letter that summarizes what your water likely means for your hair — from A (gentle) to F (heavy mineral load). Cosmetic effects on hair only.
Hair-friendly water
Minerals are low; your normal routine is enough.
Mild impact
Light buildup over time; an occasional clarifying wash helps.
Moderate buildup risk
Steady mineral deposits; hair may feel dry or dull between washes.
High risk for frizz, dullness, color fade
Buildup is fast; a chelating routine earns its place.
Severe hard water impact
A heavy mineral load; a dedicated routine and a shower filter matter here.
Your city, on the map
The HAO Global Hard Water Project™ describes cosmetic effects of water on hair. It is not a water-safety or drinking-water assessment, and it is not medical advice.
