What Are the Best Water Filtration Systems?

Written by Craig "The Water Guy" Phillips

The best water filtration systems we've tested are the AquaTru Classic for countertop reverse osmosis, Cloud RO for under-sink power, Glacier Fresh for budget-friendly portability, and Epic Pure or ZeroWater for pitcher convenience. Each one earned its spot through independent lab testing across 111+ contaminants, real certifications, and months of hands-on use. The right pick depends entirely on your water, budget, and lifestyle — and we've broken it all down for you ahead.

Key Takeaways

• AquaTru Classic leads countertop RO systems, removing 83+ contaminants including PFAS and lead, verified by independent lab testing.
• Cloud RO suits homeowners wanting under-sink installation with on-demand flow, remineralization, and NSF/ANSI 58 certification.
• Glacier Fresh gravity filter costs roughly $16 per year, making it the most affordable long-term option for off-grid use.
• ZeroWater achieves near-zero TDS readings, ideal for purism, though short filter life of 20–40 gallons raises annual costs.
• Match your system to local water contaminants—carbon filters address chlorine, while RO is required for fluoride, nitrates, and arsenic.

The Best Water Filtration Systems Right Now

After testing dozens of filters, we've narrowed the field down to five standout systems that cover nearly every budget, lifestyle, and contaminant concern.

After testing dozens of filters, five standout systems emerged — covering every budget, lifestyle, and contaminant concern worth addressing.

Whether you're eliminating PFAS and lead from city tap water, prepping for emergencies, or simply upgrading your daily hydration, there's a purpose-built solution here.

The AquaTru Classic dominates countertop RO performance.

The Glacier Fresh gravity filter earns its place in any off-grid kit.

The Epic Pure punches well above its price for families.

The ZeroWater glass dispenser satisfies purists chasing near-zero TDS.

And if you want whole-house-grade power, an under-sink RO like the Cloud RO delivers on-demand flow with remineralization built in.

Each system earned its spot through real-world testing and verified third-party certifications — not marketing claims.

How We Tested Each Water Filter & What the Lab Results Showed

To cut through the marketing noise, we built our testing methodology around two pillars: independent lab analysis and real-world daily use. We partnered with Tap Score to run pre- and post-filtration tests across 111+ contaminants—PFAS, THMs, lead, microplastics, and more—then cross-referenced every result against NSF/ANSI, IAPMO, and WQA certifications. Numbers like "non-detect" for PFAS on the AquaTru and a TDS reading of zero on ZeroWater aren't marketing claims; they're verified lab outcomes.

We scored each filter across six categories—contaminant reduction, design quality, filtration rate, setup, maintenance, and company offerings—with weightings tailored to system type. Months of hands-on use in Denver's municipal supply added the practical layer: flow times, filter swaps, O-ring quirks, and real annual operating costs.

Countertop, Undersink, or Pitcher: Which Water Filter Do You Actually Need?

1. Countertop RO (AquaTru): No plumbing, 83+ contaminants removed including PFAS and lead—ideal if you rent.
2. Under-sink RO (Cloud RO): On-demand flow, remineralization, NSF/ANSI 58 certified—worth the $600+ if you own your home.
3. Gravity stainless (Glacier Fresh): ~$16/year, portable, 98% chlorine reduction—perfect for low-budget or off-grid households.
4. Pitcher/dispenser (Epic Pure or ZeroWater): Convenient and affordable upfront, though ZeroWater's 20–40 gallon filter life makes yearly costs climb fast.

Your water report determines the technology—carbon handles chlorine and VOCs; RO handles fluoride, nitrates, and arsenic.

What to Look for When Buying a Water Filter

Once you know what's in your tap water, buying the right filter comes down to four decisions: what contaminants you're targeting, what certifications back up those claims, what the system actually costs to run, and whether it fits your kitchen and lifestyle.

Start with your contaminants—lead, PFAS, nitrates, and THMs each require different technologies. Then verify the claims: NSF/ANSI 53 covers health contaminants, while Standard 58 governs RO systems. Don't trust marketing language; trust third-party listings from NSF, IAPMO, or WQA.

Next, run the numbers. RO systems waste three to five gallons per filtered gallon and demand regular membrane swaps.

Finally, consider installation reality—countertop units plug in anywhere, while under-sink and whole-house systems require plumbing commitment. Match the system to your actual life, not your ideal one.

What Does a Water Filtration System Actually Cost to Own?

Sticker price is only half the story. What you'll actually spend depends on filter replacements, cartridge life, and gallons per dollar. Here's what ownership really looks like:

The real cost of a water filter isn't the price tag—it's what you keep paying after.

1. Gravity systems (Glacier Fresh): ~$16/year, roughly $0.005/gal—the clear long-term winner
2. Countertop/under-sink RO (AquaTru): ~$100/year at $0.20–$0.25/gal, strong value for serious filtration
3. Pitcher filters (Epic Pure): ~$100–$150/year at $0.33/gal with cartridges lasting only 150 gallons
4. Ion-exchange units (ZeroWater): ~$120–$150/year with filters exhausted at just 20–40 gallons

A $50 pitcher can quietly cost more annually than a $400 RO system. We recommend calculating your true cost-per-gallon before committing—that single habit separates smart buyers from expensive mistakes.

Frequently Asked Questions

What Is the Best Water Filtration on the Market?

We'd pick the AquaTru Classic as today's top choice — it removes 83+ contaminants, including PFAS and lead, costs roughly $0.25/gallon annually, and delivers lab-verified purity without complex installation.

What Is the Best Water Filter for Cryptosporidium?

We recommend filters certified to NSF/ANSI Standard 53 or NSF P231, specifically reverse osmosis systems or mechanical filters rated ≤1 micron, like the Sawyer Squeeze, which physically blocks Cryptosporidium's 4–6 micron size every time.

What Is the Best Water Filter for Arsenic?

For arsenic removal, we recommend a certified reverse osmosis system. Look for NSF/ANSI 58 certification or third-party lab verification — systems like AquaTru consistently achieve 100% removal, protecting you reliably.

What Is the Healthiest Water Filtration System?

We recommend reverse osmosis systems — like AquaTru or Cloud RO — as the healthiest choice. They remove 80–100% of PFAS, lead, fluoride, and microplastics, especially when paired with activated carbon filtration.