Water Filtration FAQ
Water Safety Today
Why do I need whole-house water filtration if my city already treats the water?
Municipal treatment meets EPA minimum standards and kills bacteria, but it does not come close to making your water clean. Tap water regularly contains chlorine, chloramines, heavy metals leaching from aging pipes, pesticide runoff, pharmaceutical residues, and trihalomethanes (THMs) — carcinogens formed when chlorine reacts with organic matter. Treatment plants were designed for public health minimums, not your family's daily exposure. A whole-house system removes what they leave behind.
What are PFAS, and does a whole-house water filter remove them?
PFAS (per- and polyfluoroalkyl substances), often called forever chemicals, are synthetic compounds used in nonstick cookware, food packaging, and firefighting foam. They do not break down in the environment or the human body, and they accumulate over time. The US Geological Survey estimates that close to half of Americans are drinking water that contains PFAS above advisory levels. In 2024, the EPA finalized enforceable limits for six PFAS compounds. Activated carbon-based whole-house filtration and reverse osmosis systems are the most effective residential technologies for reducing PFAS. When evaluating any system, look for NSF 401 certification for PFAS reduction.
Are there microplastics in tap water, and can a filter remove them?
Yes. Microplastics have been detected in tap water, bottled water, and in human blood. They enter water supplies through plastic pipe degradation, stormwater runoff, and industrial discharge. A multi-stage whole-house system with sediment pre-filtration physically captures microplastic particles. Reverse osmosis provides the highest level of microplastic removal at the drinking water tap. The science on long-term health effects is still developing, but the precautionary case for filtration is strong.
What are trihalomethanes (THMs) and why should I care?
Trihalomethanes are cancer-causing compounds created when chlorine reacts with naturally occurring organic matter in source water. The EPA regulates them, but regulated does not mean safe — especially after decades of daily exposure through drinking, cooking, and bathing. Chlorine vapor carrying THMs is inhaled in a hot shower at concentrations higher than most people realize. Whole-house carbon filtration removes THMs at the point of entry, before they can be absorbed, inhaled, or ingested.
How do I know what is in my water?
Start with your local Consumer Confidence Report, which your utility is required to publish annually and is also available through the EPA website. For a more detailed, independent picture, order a certified mail-in lab test. Lab tests can detect lead, PFAS, bacteria, nitrates, heavy metals, and dozens of other contaminants that utilities may not report. We recommend testing before selecting a system so your filtration is matched to what is actually in your water, not a generic guess.
Is well water different from city water?
Significantly. Well water is untreated and comes directly from an underground aquifer, so you are fully responsible for its safety. Common issues include high sediment, iron, manganese, hydrogen sulfide (that rotten egg smell), nitrates, arsenic, and coliform bacteria. The contaminant profile varies by region and even by property. We always recommend a comprehensive lab test before specifying a well water system, since the wrong filtration order can damage equipment and leave contaminants behind.
About Whole-House Water Filtration Systems
What is a whole-house water filtration system?
A whole-house system, also called a point-of-entry (POE) system, connects directly to your main water supply line and filters every drop of water before it reaches any fixture in your home. This means filtered water at every tap, shower, bath, appliance, and hose bib. Unlike a pitcher or under-sink filter that treats only a fraction of your total water use, whole-house systems protect your family's full exposure.
Is a whole-house water filter worth it?
For most homeowners, yes — and the math supports it. Whole-house filtration costs less than one cent per gallon of treated water. Bottled water for a family of four runs $500 to $1,000 per year, while a whole-house system adds up to far less on an annualized basis, covers all water use (not just drinking), and reduces single-use plastic waste. Beyond cost, the health argument is compelling: you are exposed to water through skin absorption and vapor inhalation during showers, through produce washing, and through cooking — not only through drinking.
What does a whole-house water filter actually remove?
A properly specified multi-stage system removes chlorine, chloramines, trihalomethanes, PFAS, heavy metals including lead and arsenic, sediment, rust, iron, manganese, pesticides, herbicides, volatile organic compounds (VOCs), hydrogen sulfide, and microplastics. UV stages eliminate bacteria and viruses. The key word is properly specified: a generic carbon tank removes chlorine but leaves lead. Your system should be selected based on what a water test shows is actually present in your supply.
What is the difference between a water filter and a water softener?
A water filter removes health-related contaminants including chlorine, PFAS, heavy metals, pesticides, and bacteria. A water softener removes calcium and magnesium ions that cause hard water, scale buildup, and damage to appliances. They solve different problems. About 85 percent of US homes have hard water, and most also have contaminant concerns, so the two systems are frequently combined. Our whole-house configurations can be designed to address both simultaneously.
Why is a whole-house system better than a fridge filter, pitcher, or under-sink filter?
Point-of-use filters only treat the water at a single tap, which represents roughly five percent of your total household water consumption. You are still showering and bathing in chlorinated water, which is absorbed through skin and inhaled as vapor. Your appliances are still running on unfiltered water. Your produce is being washed in unfiltered water. Whole-house filtration treats all of it at the source.
What makes The Well Build different from other water filtration providers?
The Well Build is a healthy building platform, not a hardware retailer. We approach water quality as one piece of a whole-home health strategy that includes air quality, materials, and building performance. Our consultations are diagnostic, not sales-driven. We recommend systems based on your actual water test results and home conditions, and we support installation and ongoing maintenance. We only carry and recommend systems we would put in our own homes.
Reverse Osmosis Systems
What is reverse osmosis and how does it work?
Reverse osmosis (RO) forces water through a semi-permeable membrane under pressure. The membrane's pores are small enough to block virtually all dissolved contaminants, including PFAS, heavy metals, fluoride, arsenic, nitrates, pharmaceuticals, microplastics, and bacteria. The result is hospital-grade purification at your tap. RO is the most thorough residential filtration technology available.
Does reverse osmosis remove healthy minerals from water?
Yes, RO removes nearly all dissolved solids, including trace minerals. This is frequently cited as a concern, but the evidence does not support it as a meaningful health issue. The vast majority of your mineral intake comes from food, not water. The trace amounts in tap water are nutritionally insignificant compared to a normal diet. What you gain in contaminant removal far outweighs what you lose in trace minerals.
How is reverse osmosis different from whole-house filtration?
Whole-house systems are designed for high flow rates and treat every fixture in your home, typically using activated carbon, KDF media, and UV stages. They are excellent for removing chlorine, sediment, and many chemicals. RO provides deeper purification for drinking and cooking water at a single point of use. Most high-performing setups combine both: whole-house filtration for general use and shower protection, plus an RO system under the kitchen sink for drinking and cooking water.
Under-sink or countertop RO: which should I choose?
Under-sink systems are permanently plumbed beneath your kitchen sink with a dedicated faucet. They are the right choice for homeowners who want a seamless, high-capacity installation. Countertop systems connect to your existing faucet without any plumbing modifications, making them ideal for renters or homes where cabinet space is limited. Both deliver equivalent filtration quality. The decision is about convenience and installation flexibility, not performance.
What size RO system do I need?
For 1 to 2 people, a 400 to 600 GPD (gallons per day) system is sufficient. For 3 to 4 people, 600 to 800 GPD is a comfortable range. Households of 5 or more, or anyone using RO water for cooking, ice, and large pots as well as drinking, should consider 1,200 GPD or above. When in doubt, size up: higher capacity systems perform the same filtration at lower pressure and have longer membrane life.
How much water does reverse osmosis waste?
Traditional RO systems discharge 3 to 5 gallons of water for every gallon purified. Modern high-efficiency systems operate at a 2:1 or even 1.5:1 ratio, meaning 2 gallons down the drain per gallon purified. This is a meaningful improvement and a factor we consider when specifying systems for our clients.
How do I know my RO system is working?
Use a TDS (total dissolved solids) meter, available for $10 to $15. Your source water likely reads 150 to 400 TDS. After a properly functioning RO membrane, it should read below 20 TDS. A rising TDS reading over time is your first signal that the membrane needs replacement.
Installation and Maintenance
Can I install a whole-house water filtration system myself?
Some homeowners with basic plumbing skills are comfortable with DIY installation, particularly for simpler cartridge systems. Whole-house tank systems involve cutting into your main water supply line, adding a bypass valve, and sometimes modifying existing plumbing — a job most people have a licensed plumber handle. We can refer installers in your area and provide detailed specifications to any contractor you hire. RO countertop systems require no installation at all. Under-sink RO systems are generally a 1 to 2 hour DIY job for anyone comfortable with basic plumbing.
Where does a whole-house system get installed?
Whole-house systems connect to your main water supply line before it branches to the rest of your home, typically in a basement, garage, or utility room. This placement ensures every fixture downstream receives filtered water. Under-sink and countertop systems install at the point of use, most commonly in the kitchen.
Will a whole-house water filter reduce water pressure?
No, when sized correctly. A properly matched system causes only a 1 to 3 PSI drop under normal flow, which is imperceptible. Problems arise when a system is undersized for the household flow rate or when filters become clogged and overdue for service. We size every system to your household peak demand: typically 10 GPM for 1 to 2 bathrooms, and 15 to 20 GPM for larger homes.
How long do whole-house water filtration systems last?
The tanks and hardware on quality whole-house systems are built to last decades and typically carry lifetime warranties on the vessel itself. The filtration media inside the tanks is what requires periodic service. Carbon and KDF media is recharged or replaced every 12 to 48 months depending on your water source and usage volume. Well water with high iron or sediment loads requires more frequent service than treated municipal water.
What does recharging a filter mean?
Our whole-house systems use media tanks rather than disposable cartridge filters. Rather than throwing away and replacing a plastic cartridge, the filtration media inside the tank is regenerated through a backwash and recharge process. For carbon media, this involves replacing or refreshing the carbon bed. For softening resin, a salt brine recharge restores ion exchange capacity. This approach produces less plastic waste and is more cost-effective over the life of the system.
How often do RO filters need to be replaced?
Pre-filters (sediment and carbon): every 6 to 12 months. RO membrane: every 18 to 24 months under normal use. Post-carbon polishing filter: every 6 to 12 months. Total annual filter cost for an RO system typically runs $100 to $250 — which compares favorably to $500 to $1,000 per year for bottled water for a family of four.
What does maintenance cost?
Whole-house system media service runs $500 to $900 depending on system size and water conditions, typically every 1 to 4 years. RO replacement filter sets run $100 to $250 per year. Shower filters are typically $28 to $35 per cartridge, replaced every 3 to 6 months.
Pricing, Value, and Warranty
How much does a whole-house water filtration system cost?
Entry-level cartridge systems start around $300 to $800 installed. Mid-range multi-stage tank systems with professional installation typically run $2,000 to $4,500. Premium whole-house systems that include softening, sediment, carbon, and UV stages can reach $5,000 to $8,000 installed. On a per-gallon basis, the cost of filtered water drops to well under one cent per gallon — substantially cheaper than bottled water over any meaningful time horizon.
Do you offer financing or payment plans?
We can discuss options depending on the scope of your project. Many customers use third-party financing services or credit cards with promotional rates to spread payments over time. Reach out and we can walk through what makes sense for your situation.
What is covered under warranty?
Whole-house system tanks and hardware typically carry lifetime transferable warranties on the vessel and mechanical components. Filter media and consumables are not covered under warranty, as they are maintenance items. RO systems generally carry 1 to 3 year warranties depending on the manufacturer. We share specific warranty documentation for any system we recommend, and we stand behind what we sell.
Does a whole-house water system add value to my home?
Yes. Whole-house water filtration is increasingly listed as a feature in real estate listings, particularly in markets where water quality is a known concern. The system conveys with the home, and lifetime transferable warranties mean the new owner inherits the benefit. Buyers who prioritize healthy home features specifically look for whole-house filtration. It is one of the few home investments that simultaneously improves daily quality of life and adds tangible resale value.
Ordering and Shipping
Do you ship nationwide?
Yes. Most products ship within 3 to 5 business days. Large whole-house systems may require freight shipping, and we will reach out with details before those orders are processed.
What if I order the wrong system?
Contact us immediately. We accept returns within 30 days on unopened products. Restocking fees may apply on large systems. The most effective way to avoid this is to schedule a free consultation before purchasing. We will review your water test results, home size, and water source to give you a specific recommendation, not a general one.
Consultations
What is included in a water filtration consultation with The Well Build?
Our consultations are diagnostic and free of sales pressure. We review your water test results or guide you on what to test for, assess your home size, plumbing configuration, and water source, and then give you a written system recommendation matched to your specific contaminants and budget. We also provide installation guidance and can refer licensed installers in your area. We support you after purchase as well.
Do I need a consultation, or can I order directly?
You can order directly if you already have a water test and know what system you need. If you have well water, elevated iron or manganese, known PFAS contamination, or just want confidence before spending thousands of dollars, the consultation costs you nothing and can save you from a significant mistake. Most people find it worth the 30 minutes.
How long does a consultation take?
The initial call is approximately 30 minutes. We follow up with a written recommendation within 24 to 48 hours that covers the specific system or combination we recommend, why, and what to expect from installation and ongoing maintenance.
Our Recommended RO Systems: Waterdrop
Affiliate disclosure: The Well Build may earn a commission on purchases made through links to Waterdrop products on this page. We only recommend products we have vetted and would use in our own homes. [Replace this with your complete FTC disclosure statement before publishing.]
Why does The Well Build recommend Waterdrop RO systems?
Waterdrop makes some of the most compact, efficient, and well-engineered reverse osmosis systems available for residential use. We evaluated them specifically because their tankless design solves the two biggest complaints about traditional RO systems: wasted space under the sink and slow flow rate. Their filtration performance is NSF-certified, their systems are significantly more water-efficient than older designs, and the installation process is genuinely accessible to non-plumbers. They represent a real quality-to-value proposition, which is why they are the system we recommend to most of our clients for under-sink drinking water filtration.
What Waterdrop RO systems does The Well Build carry?
We carry the core Waterdrop under-sink reverse osmosis line, including tankless systems ranging from 400 to 800 GPD. The most popular configurations for our clients are the mid-range tankless models that fit comfortably under a standard kitchen sink and deliver purified water on demand without a bulky pressure tank. We can help you identify the right model for your household size and water conditions. Shop the full Waterdrop lineup through our store.
What does Waterdrop's filtration technology remove?
Waterdrop RO membranes are certified to remove up to 99.99 percent of total dissolved solids, including lead, arsenic, fluoride, nitrates, chromium, PFAS, chlorine, chloramines, microplastics, and hundreds of other contaminants. Their multi-stage design combines sediment pre-filtration, activated carbon, and the RO membrane in a compact form factor that delivers purified water at standard flow rates. Independent third-party testing confirms performance to NSF/ANSI 58 standards.
How does Waterdrop compare to other RO brands like APEC, iSpring, or Aquasana?
Waterdrop's primary advantages over traditional brands are its tankless design, higher water efficiency ratio, and a much smaller physical footprint. Legacy systems from brands like APEC and iSpring deliver comparable filtration quality, but they require a large pressure tank that takes up most of the cabinet under your sink and waste 3 to 5 gallons per gallon purified. Waterdrop's newer models operate at closer to a 2:1 waste ratio and sit flush against the back of the cabinet. For homeowners where cabinet space and water efficiency matter, Waterdrop is the better fit.
Is Waterdrop easy to install?
Yes. Most Waterdrop under-sink systems install in under an hour with no specialized plumbing tools. The system connects to your cold water supply line under the sink and the drain line, and the dedicated faucet mounts through a hole in your sink deck or countertop. No soldering, no cutting into main lines. Waterdrop provides clear step-by-step instructions, and their customer support is available if you run into anything unexpected.
How do I maintain a Waterdrop system and how much does it cost?
Waterdrop systems use twist-and-lock filter cartridges that swap in seconds without tools. The pre-filter and carbon stages are replaced every 6 to 12 months depending on your water quality. The RO membrane is replaced every 18 to 24 months. Annual filter cost for most Waterdrop systems runs $100 to $180. The system's smart display or app alerts you when filters are due, so there is no guesswork.
Where can I buy Waterdrop systems through The Well Build?
You can shop Waterdrop systems directly through our store. Purchasing through our link supports The Well Build at no additional cost to you, and we remain available for consultation and support after your purchase. If you are unsure which model is right for your home, schedule a free consultation before ordering and we will match you to the right system. Shop Waterdrop
Still have questions? We are happy to help with water quality, system selection, or anything related to building a healthier home.