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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.

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The short answer

Clearly Filtered 3-Stage Under the Sink comes out ahead by a narrow margin (4.6 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 #1 in Best Under-Sink Water Filters
Clearly Filtered 3-Stage Under the Sink
3 sources2 derived$550as of Sep 28

The Clearly Filtered 3-Stage is the broad-spectrum carbon system, independently tested to reduce 232+ contaminants, including fluoride, lead, PFAS and arsenic, while wasting no water. Its 2,000-gallon filter life is among the longest here. Two catches: it's the costliest in this group, and 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 (per Bos Water), roughly 9 to 15 months between changes
  • — 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, which Bos Water notes is less reassuring than formal certification
  • — Significantly more expensive upfront than other carbon systems
  • — Some owners report reduced water pressure over the filter's life
$550 · Buy at clearlyfiltered.comFull review →
Frizzlife MP99
Ranked #3 in Best Under-Sink Water Filters
Frizzlife MP99
2 sourcesall derived$80as of Sep 28

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 an auto shut-off valve spares you from cutting 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 →

Derived means the reviewer published no score, so one was inferred from their written verdict. Everything else is a number the publisher printed. How we rank.

How they stack up

Clearly Filtered 3-Stage Under the Sink

More comprehensive than the budget Frizzlife MP99.

Frizzlife MP99

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 RetentionPartial: Water Filter Guru's lab measured calcium -92%, magnesium -6%, hardness -68%Yes
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
← See the full ranking of best under-sink water filters