The Water You Shower In

When I read a home, I ask where the water comes from before I ask where the bed is. Most clients have thought about their drinking water. Very few have thought about the water they shower in, wash vegetables in, or fill the kettle from at the office. The question I hear most is "whole house water filter vs reverse osmosis: which one do I need?" My answer is usually both, in layers, and only after you know what is in your water.

What is in the water coming into your home

City water is safe to drink by design, and part of that design is disinfection. Most US city water is disinfected with chlorine or chloramine (CDC). That is a public health success. It also has a side effect: disinfection creates disinfection byproducts, which the EPA tracks and regulates (EPA).

Then there is what disinfection does not address. A 2023 USGS study tested 716 tap water samples for 32 PFAS, the "forever chemicals" used in nonstick and stain-resistant products. At least 45% of US tap water contained one or more of them (USGS). The USGS has also detected trace pharmaceuticals in water supplies (USGS).

None of this is a reason for panic. It is a reason to read your water the way you would read any other part of your space: with data first.

Whole house water filter vs reverse osmosis

These two systems do different jobs. Comparing them head to head is like comparing a front door to a jewelry box. You want both, and each protects something different.

Whole-house filtration: every tap, every shower

A whole-house filter sits where the main water line enters the building. Everything downstream passes through it: the shower, the bath, the washing machine, the bathroom sink where you brush your teeth. This is the layer that reaches the water you shower in. A drinking filter under the kitchen sink does nothing for the bathroom.

The one detail most people miss: check whether your city uses chlorine or chloramine, and buy a system built for the one you have.

Reverse osmosis: the water you drink and cook with

A reverse osmosis (RO) system pushes water through a very fine membrane at a single tap, usually the kitchen. It is the finer, slower layer, reserved for the water that goes into your body and your food. Because RO strips minerals out along with everything else, I recommend systems that add minerals back afterward, called remineralization.

The systems I recommend

Layer 1: whole-house

• SpringWell whole-house filters: made in the USA, with a lifetime warranty on tanks and valves. My first recommendation for owners who plan to stay.
• SpringWell Whole Home PFAS system: for homes where the water test flags PFAS.
• Aquasana Rhino: the standard version is a strong alternative for chlorine cities.
• Aquasana Rhino Chloramines: the version to choose in chloramine cities such as San Francisco.

If you are weighing the two brands, FilterPicks has a side-by-side comparison.

Layer 2: drinking water (RO with remineralization)

• Cloud RO: my pick for an under-sink system in a kitchen you own.
• AquaTru: countertop, no plumbing. The best choice for renters, dorms, and office kitchens.
• Waterdrop G3P800: tankless, with UV, for kitchens with little cabinet space.

These picks line up with the reviews at Water Filter Guru.

Members can find Maggie Li's picks for your water in the store, grouped by layer.

If you rent

You cannot plumb a filter into a building you do not own, and you do not need to. Put a countertop RO unit such as AquaTru on the kitchen counter for drinking and cooking. For the shower, a filtered showerhead swaps in with a wrench in a few minutes and comes with you when you move. Keep the original showerhead in a drawer for move-out day. The same two pieces work in a studio, a shared flat, or a small office.

The alkaline water question

Clients ask me about Enagic Kangen machines often, so here is my honest view. Kangen units are made in Japan, sold through multi-level marketing, and cost several thousand dollars. The health claims around alkaline water are contested in the research literature (Frontiers in Medicine, 2026), so I make none.

If you already own one and you enjoy the ritual of it, keep enjoying it. Think of it as a premium ritual, not a health purchase. If you are starting from scratch, a remineralizing RO system gets you most of the way there for far less, and it is built on filtration you can verify.

The Classical Feng Shui view

The name Classical Feng Shui carries the word itself: 風水, "wind and water." Water (水, shui) is half of it. In Classical Feng Shui, water represents wealth, and the classical texts care about its quality as much as its presence: water should be clean, clear and moving. Stagnant or murky water is read as stuck or clouded prosperity.

We usually apply this through form: the direction a river runs past a building, where a fountain sits, how a driveway carries qi to the front door. I apply it one step further, to the water that actually runs through the pipes. Clean, moving water in the kitchen and bathroom is the most literal form of the principle. It is also the one you touch every single day.

Clients who install a whole-house system often tell me the first thing they notice is the shower. The chlorine smell is gone, and the morning routine feels different. That is the tangible home and the unseen home meeting in one place.

Start here

Look up your zip code in the EWG Tap Water Database today, or order a lab test if you are on a well. Write down two things: whether your city uses chlorine or chloramine, and whether PFAS were reported. Those two answers tell you which layer to install first.

Want Maggie Li to read your home? Start here.

Maggie Li is the founder of The REN Method, a Classical Feng Shui and BaZi practice. She trained under Dr. Simona F. Mainini and is certified by the American Council of Feng Shui Masters.