Maui Water Filtration Co. · Serving All of Maui

Know What's in Your Water.Clean it in a day.

Free in-home water testing and professionally installed filtration, reverse osmosis, and softener systems for Maui homes — from Kihei's hard groundwater to Upcountry chlorine. Honest results, island-wide.

Get Your Free Water Test What's My Water Like? →

Free island-wide water testingInstalled in one visitLicensed local professionalsNo pressure, ever

What We Do

Water Treatment, Matched to Your Side of the IslandReal systems. Real homes.

Maui doesn't have one kind of water — it has three. Hard mineral-rich groundwater in Central and South Maui. Soft but chlorinated surface water Upcountry. A mixed system in West Maui rebuilding trust after 2023. We test first, then install the system your water actually calls for.

Whole-house carbon water filtration system with pre-filter installed in a Maui garage

$2,500–$6,000 · INSTALLED IN 2–4 HRS

Whole-House Filtration

A carbon tank and pre-filter plumbed in where water enters the house — chlorine taste and odor gone from every tap, shower, and appliance. Mounted in the garage or utility wall, out of the way. The go-to fix for West Maui and Upcountry chlorine complaints.

Whole-house systems →

Water softener resin tank and brine tank installed beside a water heater in a Maui garage

$1,500–$5,000 · INSTALLED IN 3–5 HRS

Water Softeners & Conditioners

Resin tank plus brine tank, set next to the water heater it's protecting. The fix for Central and South Maui's hard groundwater — stop scale on fixtures, glassware, and appliances. Salt-free conditioners available where a drain or salt isn't practical.

Softeners & conditioners →

$500–$1,500 · INSTALLED IN 2–3 HRS

Reverse Osmosis Drinking Water

A compact multi-stage system tucked under the kitchen sink, feeding its own dedicated faucet. Removes 90%+ of dissolved solids — bottled-water quality on tap, and it usually pays for itself in canceled bottled water inside a year.

RO drinking water →

FREE · 15–20 MINUTES

In-Home Water Testing

Hardness, chlorine, TDS, and pH measured right at your tap with a meter and test panel, results explained on the spot in plain language. Free anywhere on Maui. If your water's fine, we'll tell you exactly that.

About free testing →

Local Knowledge

Three Islands' Worth of Water on One Island

Zone	Source	Hardness	What Usually Fixes It
Central & South Kahului, Wailuku, Kihei, Paia	Groundwater (ʻĪao aquifer area)	51–171 mg/L — moderately hard to hard	Softener/conditioner + RO for drinking water
Upcountry Kula, Makawao, Pukalani, Haiku	Treated surface water	17–69 mg/L — soft	Whole-house carbon (chlorine taste/odor) + RO
West Maui Lahaina, Kāʻanapali, Nāpili	Mixed sources	Moderate	Independent testing, whole-house carbon, RO

Hardness ranges from Maui Department of Water Supply water quality reporting. Above 75 mg/L as CaCO₃ is classified as hard water.

West Maui coastline with mountains rising behind the shore — West Maui — mixed sources, trust being rebuilt

Turquoise ocean along Maui's south shore — Central & South — hard aquifer groundwater

Green upcountry slopes of Haleakala on Maui — Upcountry — soft, chlorinated surface water

How It Works

From First Call to Clean Water in Three StepsNo pressure, ever.

1 · Free Test

We come to you, anywhere on Maui, and test your tap for hardness, chlorine, TDS, and pH — 15 to 20 minutes, results explained on the spot, no obligation.

2 · Honest Plan

You get a recommendation matched to your numbers — sometimes that's a $500 RO tap, sometimes a full system, sometimes "your water's fine, save your money."

3 · One-Visit Install

Licensed local professionals install your system in a single visit — 2 to 5 hours for most homes — and leave you a written maintenance schedule.

Service Areas

Serving Every Corner of MauiIsland-wide, always.

Kihei & Wailea

South Maui's hardest water — scale control for homes, condos, and vacation rentals.

Kihei water guide →

Kahului

Aquifer groundwater, hard on water heaters — the island's highest-payback softener zone.

Kahului water guide →

Wailuku

Older homes on mineral-rich water — testing and treatment for plantation-era plumbing.

Wailuku water guide →

Lahaina & West Maui

Independent testing and filtration for a community rebuilding — with respect, never fear.

West Maui water guide →

Kula & Upcountry

Soft surface water, noticeable chlorine — filtration country, not softener country.

Upcountry water guide →

Everywhere Between

Paia, Haiku, Makawao, Pukalani, Māʻalaea, Nāpili, Kapalua — if you're on Maui, we come to you. Testing is free island-wide.

Book your free test →

Questions

Maui Water FAQs

Is Maui tap water safe to drink?

Yes — Maui Department of Water Supply water meets all federal and state drinking water standards, and we'll never tell you otherwise. What varies hugely across the island is hardness, chlorine level, and taste. A free test shows what your specific tap delivers.

How much does a water filtration system cost on Maui?

Under-sink reverse osmosis runs about $500–$1,500 installed. Whole-house carbon filtration runs $2,500–$6,000. Softeners and conditioners run $1,500–$5,000, and combined whole-home systems $5,000–$8,000+. The free water test tells you which — if any — your home actually needs.

How long does installation take?

Almost everything is done in one visit: reverse osmosis in 2–3 hours, whole-house filtration in 2–4 hours, softeners in 3–5 hours, and full combined systems in about half a day — installed by licensed local professionals.

Which areas do you serve?

All of Maui: Kihei, Wailea, Kahului, Wailuku, Lahaina, Kāʻanapali, Kula, Makawao, Pukalani, Haiku, Paia and everywhere between. Water testing is free island-wide.

Do I need a softener or a filter?

Depends where you live. Central and South Maui (Kihei, Kahului, Wailuku) groundwater runs hard — scale problems point to a softener. Upcountry surface water is soft but chlorinated — that's a carbon filtration job. The free test settles it in fifteen minutes.