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

Clearly Filtered 3-Stage Under the Sink vs Frizzlife MP99

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

Clearly Filtered 3-Stage Under the Sink comes out ahead by a narrow margin (4.5 vs 4.4). The gap is mostly about Buyers who want the widest contaminant reduction, including fluoride and PFAS, without reverse osmosis and don't mind paying a premium. — read the strengths below before deciding.

Clearly Filtered 3-Stage Under the Sink
Higher ratedRanked #2 in Best Under-Sink Water Filters
Clearly Filtered 3-Stage Under the Sink
$495

The Clearly Filtered 3-Stage is the broad-spectrum carbon system, independently tested to reduce 232+ contaminants, including fluoride, lead, PFAS and arsenic, while keeping beneficial minerals and wasting no water. Its 2,000-gallon filter life is among the longest here. The catches are price (it's the costliest in this group) and that it carries only one full NSF certification despite extensive third-party testing. For maximum contaminant breadth without RO, it's excellent.

Strengths
  • — Independently tested to reduce 232+ contaminants including fluoride, lead, PFAS and arsenic
  • — Long 2,000-gallon filter life, roughly 9 to 15 months between changes
  • — Retains beneficial minerals, no water waste, no drain line or dedicated faucet needed
Watch-outs
  • — Holds only one full NSF certification (NSF 42) despite broad third-party testing
  • — Significantly more expensive upfront than other carbon systems
  • — Some owners report reduced water pressure over the filter's life
$495 · Check Price on AmazonFull review →
Frizzlife MP99
Ranked #4 in Best Under-Sink Water Filters
Frizzlife MP99
$80as of Jun 8

The Frizzlife MP99 is a compact, affordable two-stage under-sink filter with a clever twist-change cartridge and a strong 1.4 GPM dedicated faucet. Tested to NSF/ANSI 42/53, its 0.5-micron media reduces lead, chlorine and 70-80 VOCs while keeping beneficial minerals, and the auto shut-off valve means no need to cut the water supply at filter-change time. It's a tidy, low-cost choice for essential filtration with an easy maintenance routine.

Strengths
  • — Two-stage 0.5-micron filtration reduces lead, chlorine and 70-80 VOCs
  • — Tested to NSF/ANSI 42/53 by IAPMO R&T
  • — Auto shut-off valve lets you twist-change the cartridge without shutting off water
Watch-outs
  • — Shorter filter life than long-life cartridges like the Waterdrop 15UA
  • — Two-stage design has less breadth than three-stage systems
  • — Requires a hole for the dedicated faucet
$80 · Buy at frizzlife.comFull review →

How they stack up

Clearly Filtered 3-Stage Under the Sink

Broader contaminant testing than the Aquasana Claryum AQ-5300+, Waterdrop 15UA and Filtrete 3US-PS01, with longer filter life, but at a much higher price and with fewer formal NSF certifications than the Aquasana. More comprehensive than the budget Frizzlife MP99.

Frizzlife MP99

A lower-cost alternative to the Aquasana Claryum AQ-5300+ and Clearly Filtered 3-Stage, with a dedicated faucet the Waterdrop 15UA and Filtrete 3US-PS01 lack. Its twist-change cartridge is more convenient than the Filtrete but its filter life is shorter than the Waterdrop 15UA.

Specs side-by-side

SpecClearly Filtered 3-Stage Under the SinkFrizzlife MP99
Filtration3-stage Affinity media2-stage compound, 0.5 micron
CertificationsNSF/ANSI 42, 372 (broad third-party testing)NSF/ANSI 42/53 (IAPMO tested)
Contaminants Reduced232+ (fluoride, lead, PFAS, arsenic)Lead, mercury, chlorine, 70-80 VOCs
Filter Life2,000 gallons / 9-15 months—
Mineral RetentionYesYes
Water WasteNone—
FaucetUses existing faucet (no separate faucet)Dedicated brushed nickel included
Reduction Rate90-99% across tested contaminants—
Flow Rate—1.4 GPM @ 60 psi
Maintenance—Twist-change with auto shut-off
Replacement Filter—FZ-2 cartridge
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