Reverse osmosis is the most reliable point-of-use treatment for PFAS, lead, nitrates, arsenic, and chromium-6. No other common consumer filter technology matches it on contaminant removal range.

The catch: not all RO systems are certified for the same things. We looked at certification data, removal test results, and real-world installation experience across seven systems.

What to Look For

NSF/ANSI 58 certification — the baseline. This confirms the system was independently tested for contaminant reduction.

NSF P473 — additional certification specifically for PFOA and PFOS reduction. Not all NSF 58-certified systems carry P473.

Lead removal data — look for systems certified to remove lead to below 10 ppb. The best systems achieve 97–99% reduction.

Production capacity — measured in gallons per day (GPD). A household of four needs at least 50 GPD. Tankless systems with 400–600 GPD capacity essentially eliminate wait time for filtered water.

Waste water ratio — expressed as filtered:drain. A 1:1 ratio means you waste one gallon for every gallon filtered. 3:1 means three wasted per one filtered. Better ratio = lower water bill, less waste.

Our Top Picks

Best Overall: APEC Water ROES-50

NSF certifications: NSF 58 (certified), NSF P473 (PFOA/PFOS)

PFAS removal: Tested to reduce PFOA and PFOS to below 0.1 ppb from 200 ppb feed water (>99.95% reduction in NSF P473 testing)

Lead removal: 98.7% in NSF 58 testing

Production: 50 GPD with tank storage

Waste ratio: ~3:1

Price: ~$200 (unit), ~$60–90/year (filters)

Stages: 5 (sediment, two carbon pre-filters, RO membrane, post-carbon polish)

What we like: APEC is one of the few brands to publish their actual NSF 58 test data with specific contaminant reduction percentages. The system has a long track record of reliability. Filter prices are reasonable. Customer support is better than most.

What we don’t like: 3:1 waste ratio is on the higher end for a modern system. Tank-based design means filtered water takes a few hours to accumulate if you drain it. Installation requires a faucet hole or drilling.

Best for: Households with PFAS or lead concerns who want certified performance at a moderate price.

Check price on Amazon (affiliate link — see disclosure above)

Best Tankless: Waterdrop G3 P800

NSF certifications: NSF 58, NSF 42, NSF 372 (lead-free components)

PFAS removal: Waterdrop reports >99% PFOA/PFOS reduction; not currently NSF P473 certified

Lead removal: 99.9% in published testing

Production: 800 GPD (essentially on-demand flow)

Waste ratio: 3:1 (smart drain valve reduces waste when not in use)

Price: ~$370 (unit), ~$120/year (filters — proprietary)

Stages: 7 (sediment, pre-carbon block, RO membrane, second RO membrane, UV, post-carbon)

What we like: The 800 GPD capacity means no tank — water pressure from the dedicated faucet is comparable to a regular tap. The UV stage kills bacteria (useful for some well water applications). Small footprint under the sink.

What we don’t like: Waterdrop doesn’t carry NSF P473. Their internal PFAS testing shows high removal rates, but P473 would be independent verification. Proprietary filters lock you into Waterdrop pricing (generally more expensive than generic). Replacement filter costs add up over time.

Best for: Tech-forward buyers who want tankless flow and don’t mind paying more for proprietary filters.

Check price — Waterdrop G3 (affiliate link)

Best Budget: iSpring RCC7

NSF certifications: NSF 58

PFAS removal: No NSF P473; iSpring reports >96% reduction for PFAS (internal testing)

Lead removal: 98% in NSF 58 testing

Production: 75 GPD with tank storage

Waste ratio: ~3:1

Price: ~$160 (unit), ~$45–70/year (filters — widely available third-party)

Stages: 5 (sediment, two GAC carbon, RO membrane, post-carbon polish)

What we like: Significantly cheaper than comparable systems. Filter replacements are widely available from multiple suppliers, so you’re not locked in. 75 GPD capacity is more than enough for most households.

What we don’t like: No NSF P473. If PFAS certification is a priority, this isn’t the pick. Internal PFAS removal data shows solid results, but NSF P473 carries more weight for making documented decisions.

Best for: Budget-conscious buyers whose main concern is general water quality improvement rather than documented PFAS certification.

Check price on Amazon (affiliate link)

The Certification Question

If you’re buying primarily because of PFAS concerns, NSF P473 matters. Only systems that have gone through NSF’s P473 testing for PFOA and PFOS can make the NSF-certified PFAS removal claim.

Waterdrop and iSpring publish their own internal PFAS test data, which shows high removal rates, but internal testing isn’t the same as independent certification.

For most households, APEC’s ROES-50 with NSF P473 is the cleaner choice if PFAS is the primary driver.

Ongoing Costs

All RO systems require filter changes. Budget $50–$120/year for filter replacements depending on brand and water quality. Systems with heavy sediment loads will need pre-filter changes more often.

The RO membrane itself lasts 2–5 years. Replacement membranes run $30–$80 depending on brand.

Track total cost of ownership over 5 years, not just purchase price. The cheapest unit may cost more in filters if it uses proprietary cartridges.