Whole-Home Water Filtration vs. Under-Sink Systems

Quick Answer: Which Water Filtration System Do You Need?


Choose an under-sink system if:
– You only want better-tasting drinking water
– Your water has no visible quality issues (scale, staining, sediment)
– You’re on municipal water with minimal complaints
– Budget is under $1,500

Choose a whole-home system if:
– You see scale buildup on fixtures or in your water heater
– You have well water with iron, manganese, or sediment
– You experience dry skin/hair from chlorinated showers
– Your appliances are failing prematurely from water quality issues
– You want consistent water quality throughout your entire home

Cost range: Under-sink systems: $300-$1,500 | Whole-home systems: $2,000-$6,000+

Best for most homes: Whole-home Atlas Filtri carbon/softening system + under-sink RO for drinking water



What Massachusetts Homeowners Should Actually Choose

If you live in Massachusetts, you already know water quality can vary dramatically from one town to the next.


In some homes, you’ll see white scale crust building up on faucets and showerheads within months. In others, the water tastes fine but leaves your skin feeling tight and dry all winter. And if you’re on a well? You might be dealing with rust stains in the toilet, sediment in the washing machine, or water that smells faintly of metal.


The question we get all the time at Endless Energy is simple:


Should I install a whole-home water filtration system, or is an under-sink system enough?


The honest answer? It depends on what problem you’re trying to solve.


Let me walk you through both options so you can figure out what actually makes sense for your home.

What Is a Whole-Home Water Filtration System?

A whole-home system—also called a point-of-entry system—treats water as it enters your house, right after the main shutoff valve.


That means every tap, every shower, every appliance, and even your outdoor hose gets filtered water.


At Endless Energy, we install Atlas Filtri whole-home filtration systems. They’re Italian-engineered, built to last, and designed to handle the kinds of water problems we see all over Massachusetts—whether that’s chlorine from municipal sources or iron and sediment from private wells.

What a whole-home system can address:

  • Sediment – Sand, silt, rust particles
  • Chlorine and chloramines – Common in municipal water
  • Hard water – When paired with a softener
  • Iron and manganese – The stuff that stains your sinks and toilets
  • Certain chemicals – Depending on the filter media you choose

What it actually improves in your daily life:

  • Better showers – No more chlorine smell or that tight, dry skin feeling
  • Healthier hair and skin – Especially noticeable in winter
  • Longer-lasting appliances – Water heaters, dishwashers, and washing machines don’t have to fight through scale and sediment
  • Cleaner fixtures – Less white buildup on faucets and showerheads
  • Consistency – Every tap in the house has the same quality water


Here’s the thing: if your problem goes beyond just drinking water—like you’re seeing scale deposits, your water heater is failing prematurely, or your skin feels like sandpaper after every shower—whole-home filtration is almost always the better long-term move.


You’re not just treating symptoms. You’re protecting your plumbing infrastructure.

What Is an Under-Sink Water Filtration System?

An under-sink system, also called a point-of-use system, filters water at a single faucet, usually your kitchen sink.

Most commonly, this is either a carbon filter or a reverse osmosis (RO) unit.


We also install Atlas Filtri under-sink systems for customers who want better drinking water without committing to a whole-home setup. They’re compact, effective, and designed to fit neatly under a standard kitchen cabinet.

What an under-sink system improves:

  • Taste and odor – Gets rid of that chlorine taste
  • Chlorine removal – Makes water taste cleaner
  • Drinking and cooking water quality – Coffee, tea, and pasta water all benefit
  • Certain dissolved solids – If you go with an RO system

What it does NOT improve:

  • Shower water – You’re still showering in unfiltered water
  • Laundry water – Your washing machine is still getting hard water
  • Scale buildup in pipes – The rest of your plumbing is unprotected
  • Water heater protection – Sediment and minerals are still entering your tank


If your main complaint is that the water tastes bad or smells like a pool, an under-sink system might be all you need.


But if you’re dealing with dry skin, scale buildup, or appliance issues, an under-sink filter won’t solve those problems. It’s treating one faucet. Everything else in your house is still running on unfiltered water.

The Key Difference: Scope of Protection

Think of it this way:

  • Under-sink system = targeted solution for drinking water
  • Whole-home system = infrastructure solution for your entire house


If you only care about drinking water taste, an under-sink system is simple, affordable, and effective.


If you care about protecting your plumbing, improving comfort in the shower, extending the life of your appliances, and treating water consistently throughout your home, whole-home filtration makes more sense.


One is a band-aid. The other is a system upgrade.

Massachusetts-Specific Water Challenges

Water problems in Massachusetts aren’t one-size-fits-all. What you’re dealing with depends heavily on whether you’re on municipal water or a private well—and even then, it varies by town.

If You’re on Municipal Water

Most towns in Massachusetts treat water with chlorine or chloramines to kill bacteria. That’s good for public health, but it’s not great for your skin, hair, or appliances.


Here’s what we hear from municipal water customers:

  • “The water tastes like a swimming pool.”
  • “My skin feels dry and tight after every shower, especially in winter.”
  • “My hair is brittle and lifeless.”
  • “I’m seeing white scale buildup in my high-efficiency water heater.”


A whole-home carbon filter—like the Atlas Filtri systems we install—can dramatically improve the shower experience. 


You’ll notice the difference in your skin and hair within a week.


An under-sink system will fix the taste issue, but it won’t change how your skin feels after a shower. And it won’t protect your water heater from scale.

If You’re on a Private Well

Well water is a whole different ballgame.


Common well water problems in Massachusetts include:

  • Iron staining – That orange-brown ring in your toilet and sink
  • Manganese – Black staining and metallic taste
  • Sediment – Grit in your washing machine or dishwasher
  • Hardness – White scale everywhere
  • Sulfur smell – That rotten egg odor (less common, but it happens)


In these situations, an under-sink system is almost never enough.


You usually need a combination of:

  • Sediment filtration – To catch particles before they hit your appliances
  • Iron removal – Specialized media that pulls iron out of the water
  • Water softening – To handle hardness and prevent scale
  • Sometimes UV disinfection – Especially if you’re in a rural area with bacteria concerns


That’s whole-home territory. Atlas Filtri makes modular systems that let us configure the right combination of filtration stages for your specific well water chemistry. We test first, then design a system based on what’s actually in your water—not a generic template.

Cost Comparison: What to Expect

Let’s talk money.

Under-Sink System

  • Lower upfront cost – Usually a few hundred to around $1,500 depending on the system
  • Minimal installation complexity – Most can be installed in an hour or two
  • Ongoing maintenance – Cartridge replacements once or twice a year, typically $50–$150 per change

Whole-Home System

  • Higher initial investment – Typically $2,000–$6,000+ depending on what you need (sediment, carbon, softener, iron removal, etc.)
  • Professional installation required – This isn’t a DIY project
  • Periodic maintenance – Media changes, salt refills (if you have a softener), occasional filter replacements
  • Long-term savings – Protects your plumbing and extends appliance life, which can save you thousands down the road


Here’s the reality: under-sink systems are cheaper upfront, but they don’t prevent the problems that cost real money, like replacing a water heater at 8 years instead of 15, or dealing with clogged fixtures and failing appliances.


Whole-home systems are an investment in your home’s infrastructure. The Atlas Filtri systems we install are built to last, with quality components designed for New England basements and mechanical rooms. We’re not installing disposable equipment. We’re installing systems that are still going to be working 10, 15, even 20 years from now.

When We Recommend Each at Endless Energy

At Endless Energy, we don’t default to the most expensive option just because we can. We start with water testing, figure out what’s actually in your water, and then recommend the simplest solution that solves your problem.

We typically recommend an under-sink system when:

  • Municipal water tests clean – No sediment, no iron, minimal hardness
  • The homeowner only dislikes the taste – Everything else is fine
  • There are no scaling issues – Fixtures look good, appliances are performing normally
  • Budget is tight – And drinking water quality is the priority

We typically recommend a whole-home system when:

  • There’s visible scale buildup – On faucets, showerheads, inside the water heater
  • The water heater is failing early – Especially if it’s full of sediment
  • Iron staining is present – Rust-colored marks in sinks, toilets, or tubs
  • Well water is involved – Almost always requires whole-home treatment
  • The homeowner wants consistent water quality – Throughout the entire house
  • Skin and hair are suffering – Dry, itchy skin from chlorinated showers

The Best Setup? Often It’s Both.

Here’s what we see in a lot of homes:


  • Whole-home Atlas Filtri carbon or softening system – Handles chlorine, sediment, and hardness
  • Plus an RO system at the kitchen sink – For premium drinking water


That combination gives you infrastructure protection and the cleanest possible drinking water. The whole-home system does the heavy lifting. The under-sink RO polishes the water at the tap you use most.


It’s not the cheapest option, but it’s the most comprehensive.

Can You Install These Yourself?

Under-sink systems? Some people do. If you’re handy and comfortable working under a sink with basic plumbing, a simple carbon filter isn’t that complicated. RO systems are trickier but still manageable for a confident DIYer.


Whole-home systems? No. Just no.


These systems tie into your main water line, often require backwash drains, electrical connections for UV systems, and precise sizing based on flow rates and water chemistry. If it’s not installed correctly, you can end up with pressure drops, leaks, or a system that doesn’t actually solve your water problem.


We’ve seen homeowners try to DIY a whole-home system and end up calling us to fix it. It’s almost always more expensive to fix a bad install than it would’ve been to do it right the first time.

How Do You Know What Your Water Actually Needs?

You test it.


Not with one of those basic home test kits. Those are fine for a rough idea, but if you’re making a real investment in water treatment, you want accurate data.


We offer professional water testing that tells you:

  • Hardness levels
  • Iron and manganese content
  • pH
  • Chlorine or chloramine presence
  • Sediment and turbidity
  • Total dissolved solids (TDS)


Once we know what’s in your water, we can recommend the right system. Not the most expensive one. Not the one with the best margin. The one that actually solves your problem.

The Bottom Line

There isn’t a “better” system in some universal sense. There’s only the right system for your home.


If your concern is drinking water taste, an under-sink system is simple, effective, and affordable.


If your concern is plumbing protection, appliance longevity, skin comfort, and consistent water quality throughout the house, whole-home filtration is the smarter long-term investment.


And if you want both? You can absolutely have both.


We work with Atlas Filtri because their equipment matches how we approach HVAC: reliable, well-engineered, and designed to solve real problems without unnecessary complexity or gimmicks.


If you’re tired of guessing what’s wrong with your water—or tired of Band-Aid solutions that don’t actually fix anything—let’s test your water and figure out the right answer for your house.

Ready to Find Out What Your Water Actually Needs?

At Endless Energy, we provide professional water testing and clear recommendations based on your specific home—not generic assumptions or upsells.


For all your heating, cooling, and water quality needs, you need Endless Energy.


Call us at 508-299-5561
Self-Schedule Online: http://www.goendlessenergy.com