
What the product listing won't tell you
Know before you buy
The OptimH2O's Exceptional rating comes from its certification depth, not its maintenance convenience. NSF P473 — the PFAS-specific standard — plus four other NSF certifications is the broadest certified coverage in this category. The honest tradeoff is the pre-filter: 365 gallons means roughly twice-yearly replacements at roughly $211 per year. That's the real cost of this system's certification breadth. If that schedule fits your routine, the safety credentials are the strongest available in a DIY under-sink format.
Aquasana
Aquasana OptimH2O Reverse Osmosis + Claryum Under Counter Water Filter System
Aquasana
Aquasana OptimH2O Reverse Osmosis + Claryum Under Counter Water Filter System
$165.00
We may earn a commission. It doesn't affect our scores.
You need NSF P473 — the PFAS-specific certification — combined with NSF 53 lead coverage, NSF 401 emerging contaminants, and NSF 58 comprehensive RO in a single under-sink system.
You want full test transparency: Aquasana's certified products page lets you verify every contaminant claim before you buy.
You're comfortable with semi-annual filter replacements and building that maintenance habit in exchange for the deepest certification profile in the category.
Your household water has documented PFAS, lead, chloramine, or emerging contaminant concerns that require formal NSF certification to address.
Frequent filter changes feel unmanageable — at standard household usage the pre-filter needs replacing every 6 months.
You're optimizing for low annual running cost — roughly $211 per year in filter replacements is above average for an under-sink system.
You want a simple install without drilling a new hole — the dedicated faucet requires a new hole in your sink deck or counter.
Specs the product listing doesn't explain
What your food and family come into contact with every use
Ease of use, maintenance, and longevity
See exactly what's in this under sink water filter
Free account unlocks full material breakdown, safety test results, and spec details.
3 criteria - open any layer to see exactly what we found
“Will this filter actually protect my family from PFAS and other harmful contaminants?”
The scoring rationale is locked
Free account unlocks exactly why this product scored the way it did.
Criteria
Verified retailer - current pricing
Starting price
$165
We earn a small commission on purchases. It never influences our scores - R3 is funded by readers, not brands.
Did the Aquasana OptimH2O Reverse Osmosis + Claryum Under Counter Water Filter System pass our safety screen?
Free account unlocks the full verdict, pillar scores, spec values, and which other under sink water filters made our list.
“How often will I need to replace filters, and is the maintenance realistic?”
The scoring rationale is locked
Free account unlocks exactly why this product scored the way it did.
“How disruptive is installation, and is the daily experience practical?”
The scoring rationale is locked
Free account unlocks exactly why this product scored the way it did.