Head-to-head · Best Under-Sink Water Filters

Aquasana Claryum AQ-5300+ vs Aquasana SmartFlow Reverse Osmosis

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

The short answer

Aquasana Claryum AQ-5300+ comes out ahead by a narrow margin (4.7 vs 4.6). The gap is mostly about users wanting heavy-metal removal without RO water waste — read the strengths below before deciding.

Higher ratedRanked #1 in Best Under-Sink Water Filters

Aquasana Claryum AQ-5300+

4.7

$260

The Claryum is the best-overall non-RO pick — Aquasana's flagship removes 77 contaminants without RO water waste.

Strengths

— Removes 99% of 77 contaminants including lead, mercury, PFAS
— No water waste (not RO)
— Environmental-friendly cartridge design

Watch-outs

— Doesn't remove fluoride / arsenic (RO does)
— Higher upfront than basic filters
— Cartridge replacement every 6 months

$260 · Check Price on Amazon Full review →

Ranked #4 in Best Under-Sink Water Filters

Aquasana SmartFlow Reverse Osmosis

4.6

$399

The SmartFlow is the tankless RO pick — Aquasana's compact RO with smart leak detection saves space.

Strengths

— NSF 58 certified RO
— 96% contaminant removal
— Tankless design saves space

Watch-outs

— Premium price
— Aquasana brand newer to RO than APEC
— Initial install learning curve

$399 · Check Price on Amazon Full review →

How they stack up

Aquasana Claryum AQ-5300+

Best non-RO. No water waste. Lead + mercury removal.

Aquasana SmartFlow Reverse Osmosis

Tankless RO. Smart leak detection. Premium price.

Specs side-by-side

Spec	Aquasana Claryum AQ-5300+	Aquasana SmartFlow Reverse Osmosis
Type	Non-RO multi-stage	Tankless RO
Contaminants	77 removed	—
Waste	None	—
Cartridge	6-month	—
Cert	—	NSF 58
Removal	—	96% contaminants
Feature	—	Smart leak detection

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