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Aquasana SmartFlow Reverse Osmosis Under Sink Water Filter

Name: Aquasana SmartFlow Reverse Osmosis Under Sink Water Filter
Brand: Aquasana
Price: 224.99 USD

Reverse osmosis · 0.7 GPM · Treats nitrates, pfas · $225 (sale) at Aquasana as of Oct 2026

The Aquasana SmartFlow (AQ-SFRO2) is a four-stage under-sink reverse osmosis system that treats drinking water at a dedicated faucet, not the whole house: carbon block, RO membrane, Claryum carbon and ion-exchange stage, and remineralizer. It is certified by WQA, not NSF, to NSF/ANSI 42, 53 (which covers PFOA and PFOS), 58, 401 and CSA B483.1. WQA's listing includes nitrate and nitrite under NSF/ANSI 58; the performance data sheet gives 78% overall reduction, for water with up to 27 mg/L nitrate as N at 40 psi or more. A test kit is in the box.

Faucet flow is 0.7 GPM, with 51.4 GPD membrane production and a 25.7 GPD daily rate. Feed limits are 40-80 psi, 1,000 ppm TDS, 10 gpg hardness, 3 ppm chlorine and pH 4-10, so hard or high-TDS well water needs pre-treatment. Carbon and Claryum cartridges last 250 gallons or 6 months, the membrane 12 months. The tank is 3.2 gallons on the page, 2.5 in the manual.

Price was $224.99 at aquasana.com as of Oct 2026 (sale), 50% off a $449.99 MSRP, and in stock. Aquasana recommends professional installation but publishes a manual; the drain needs a 1 in. air gap to keep the NSF/ANSI 58 listing. Warranty is 2 years per the product page and the warranty PDF (24 months), though the manual's body text still says 12 months; there is a 90-day satisfaction guarantee.

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Aquasana SmartFlow Reverse Osmosis Under Sink Water Filter well water reverse osmosis

Specifications

Verified 2026-10-06. Fields the manufacturer does not publish are marked “Not stated”.

Aquasana SmartFlow Reverse Osmosis Under Sink Water Filter specifications
Model	AQ-SFRO2-CHR (chrome faucet). AQ-SFRO2-BN brushed nickel and other faucet finishes are the same system; replaces the earlier OptimH2O AQ-RO-3, whose aquasana.com URL now redirects to this product.
Type	Reverse osmosis
Treats	Nitrates, PFAS; also nitrites, fluoride, arsenic, lead, radium, chlorine and chloramines, VOCs, microplastics, cysts, pharmaceuticals (NSF/ANSI 401)
Service flow	0.7 GPMDedicated-faucet flow of 0.7 GPM is published on the product page; this is a point-of-use system, not a whole-house flow rating. Membrane production 51.4 GPD; daily production rate 25.7 GPD (owner's manual: recovery 42.8%, efficiency 27.4%). Supply pressure 40-80 psi, max TDS 1,000 ppm, max hardness 10 gpg, max chlorine 3 ppm, pH 4-10.
Capacity	250 gallonsMembrane production 51.4 gpd; daily production rate 25.7 gpd (performance data sheet, Jan 2026: recovery 42.8%, efficiency 27.4%). Stage 1 and 3 carbon/Claryum cartridges: 250 gallons or 6 months; RO membrane 12 months; remineralizer 6 months. Storage tank: owner's manual AQ-SFRO2-OM-20260804 (Aug 2026) specifies 'Storage tank capacity: 2.5 gallons (9.46 liters)'; the product-page FAQ says 'The total volume of the holding tank is 3.2 gallons', with 1.4-3.2 gallons held depending on inlet pressure.
Media / technology	Carbon block pre-filter, reverse osmosis membrane, Claryum selective filtration (activated and catalytic carbon with ion exchange), remineralizer
Stages	4
Connection	1/2 in. faucet hole; 1/4 in. and 3/8 in. tubing
Installation	DIY or proProduct page says professional installation is recommended because drilling a faucet hole may be required, but Aquasana publishes a step-by-step owner's manual and installation videos for homeowners. Requires a cold-water tee, drain saddle and 1/2 in. faucet hole; manual says the drain line needs a 1 in. air gap (or air-gap faucet) to keep the NSF/ANSI 58 certification.
Warranty	2-year manufacturer warranty2-year limited warranty: stated on the product page, in the heading of the manual's warranty section, and in the standalone 'SmartFlow Reverse Osmosis 2-Year Limited Warranty' PDF linked from the product page, which says 'This Warranty runs for 24 months (730 days) from the date of purchase'. The warranty text inside owner's manual AQ-SFRO2-OM-20260804 still says '12 months (365 days)' under the same 2-Year heading. Registration not required; original owner; proof of purchase needed if bought from a reseller; filter cartridges excluded. 90-Day Satisfaction Guarantee. Water for Life auto-ship members get an extended limited warranty.
Certifications	NSF/ANSI 42; NSF/ANSI 53 (includes PFOA/PFOS); NSF/ANSI 58; NSF/ANSI 401; CSA B483.1; NSF/ANSI/CAN 372 (lead content)Certifier is WQA, not NSF. Product page: 'WQA tested and certified to NSF/ANSI Standards 42, 53 (includes P473), 58, 401, and CSA B483.1'. Performance data sheet (Jan 2026): 'System tested and certified by WQA to NSF/ANSI Standards 42, 53, 58, 401, and CSA B483.1 for the reduction of the claims specified on the Performance Data Sheet and at www.WQA.org.' WQA product database (find.wqa.org, read 2026-10-06) lists Aquasana AQ-SFRO2 under NSF/ANSI 58 (arsenic V at 50 ppb influent, barium, cadmium, copper, fluoride, hexavalent and trivalent chromium, nitrate, nitrite, radium 226/228, selenium, TDS, turbidity), NSF/ANSI 53 (asbestos, cyst, lead, mercury, MTBE, PFOS, PFOA, VOC as chloroform), NSF/ANSI 42 (chloramine, chlorine, particulate class I, taste and odor), NSF/ANSI 401 (15 emerging compounds plus microplastics), CSA B483.1 and NSF/ANSI/CAN 372. Data-sheet overall reductions: nitrate/nitrite 78% (74% minimum), PFOA and PFOS 99.7%, fluoride 90%, arsenic (pentavalent) 96%, TDS 96.4%, lead 99.8% at pH 6.5 and 99% at pH 8.5. Data-sheet limit: 'acceptable for treatment of influent concentrations of no more than 27 mg/L nitrate and 3 mg/L nitrite in combination measured as N and is certified for nitrate/nitrite reduction only for water supplies with a pressure of 40 psi or greater.' P473 is not a separate listing; PFOA/PFOS sit under NSF/ANSI 53. NSF certified-product database (info.nsf.org), searched 2026-10-06: no matching listing found for this model; the certification above is WQA's, not NSF's.
Dimensions	Manifold 15 x 4.5 x 12.93 in. (L x W x H); tank 13.74 in. H x 9.06 in. D
Weight	Not stated
Price	$225 (sale) at Aquasana as of Oct 2026

Published features

Patented SmartFlow technology for more pure water, less water waste and longer filter life
Claryum filtration paired with reverse osmosis
Remineralization restores beneficial minerals
Compact under-sink chassis and smaller tank
All-metal dedicated faucet in four finishes
57% greater efficiency than the previous model
WQA certified to NSF/ANSI 42, 53, 58, 401 and CSA B483.1
Nitrate/nitrite test kit included

Pros and cons

Pros

Only RO system researched with nitrate and nitrite among its certified NSF/ANSI 58 claims (WQA listing; 78% overall reduction on the performance data sheet)
PFOA/PFOS reduction certified by WQA under NSF/ANSI 53 (99.7% on the performance data sheet), plus NSF/ANSI 42 and 401 claims
0.7 GPM faucet flow and 25.7 GPD daily production from a compact manifold
2-year warranty and 90-day satisfaction guarantee; half-price sale still running on 2026-10-06

Cons

Max feed TDS 1,000 ppm, hardness 10 gpg and chlorine 3 ppm; well water above these limits needs pre-treatment
Cartridges rated only 250 gallons / 6 months
Certified nitrate/nitrite reduction is 78% overall, and only at 40 psi or more and up to 27 mg/L nitrate as N
Manual and product page disagree on tank size (2.5 vs 3.2 gal), and the manual's warranty text says 12 months under a 2-Year heading
Aquasana recommends professional installation

Our take

This is the RO system to buy for a nitrate problem: it is the only one we researched with nitrate and nitrite among its certified NSF/ANSI 58 claims (78% overall reduction, so check your nitrate level against that), and PFOA/PFOS reduction is certified under NSF/ANSI 53. Check your test against the 10 gpg hardness and 1,000 ppm TDS limits first, budget for 6-month cartridge changes, and retest the treated water with the included kit. The sale price makes it cheaper than the APEC ROES-50.

Not sure it is the right size for your flow and your water test? Work through the sizing guide, or compare every system we cover on the best well water filtration systems (2026) list.

Where to buy

$225 (sale) at Aquasana as of Oct 2026. Prices change; the links open the current listing.