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FilterScored

Water filter · under-sink

Frizzlife SK99 Under-Sink Filter

A direct-connect 3-stage under-sink filter with a 0.5 micron carbon block, IAPMO certified to NSF/ANSI 42 and 53 for chlorine, lead and chloramine.

6.8
Mixed
Composite (0-10), water-v1.0
Confidence: Partial

Flags

  • · Marketed for PFAS removal but not certified to P473 (or 53+401).

Flags indicate missing certifications or data gaps under our rubric, not a confirmed finding that a product fails to perform.

Total cost of ownership

Cost / gallon
$0.031
~Annual filters
$34/yr

Certifications

Overview

The Frizzlife SK99 Under-Sink Filter is a under sink water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, lead. It is also marketed for chloramine, mercury, cadmium, fluoride, VOCs, PFOA, PFOS, sediment, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.031 per gallon.

By the numbers

Certified to reduce
chlorine taste and odor, lead
Marketed, no certification found
chloramine, mercury, cadmium, fluoride, VOCs, PFOA, PFOS, sediment
Format
under sink
Cartridge life
1,600 gallons
Cost per gallon
$0.031
Annual filter cost (~1,100 gal)
$34/yr
Flow rate
2 gpm
Install
direct-connect under-sink, tool-free twist-in cartridges
Certifications
IAPMO NSF/ANSI 42; IAPMO NSF/ANSI 53; IAPMO NSF/ANSI 372

Strengths

  • + Total Cost of Ownership: 8.0/10
  • + Certification Independence: 8.0/10
  • + Capacity & Flow Fit: 10.0/10

Watch-outs

  • - Verified Contaminant Reduction: 4.0/10
  • - Marketed for PFAS removal but not certified to P473 (or 53+401).

Who it is for

  • · Homes with lead service lines or older plumbing (certified for lead)
  • · Cost-conscious buyers - very low cost per gallon

Who should skip it

  • · Anyone buying specifically for PFOA - it is marketed for it but not certified

What to know before buying

  • · The current SK99-NEW is IAPMO-certified to NSF/ANSI 42, 53, and 372 at a 0.5 micron rating; chloramine appears in marketing copy but is not part of the certified scope.
  • · It is a 3-stage under-sink system using cartridges replaced on different cycles of roughly 3 to 6, 8 to 12, and 12 to 18 months (sold together as the M3005 set).
  • · It installs under the sink in about 15 minutes without a plumber, using a twist-in cartridge design; flow is rated around 1.5 to 2 GPM.

How it scored

Verified Contaminant Reduction

4.0/10 · 35%

Held NSF/WQA/IAPMO certifications for the contaminants that matter. A claim is not a certification.

  • +3NSF/ANSI 53 certified for lead ANSF/53 lead - Independently certified to reduce lead under NSF/ANSI 53.
  • +1NSF/ANSI 42 certified for chlorine ANSF/42 chlorine - Certified to reduce chlorine taste and odor.

Total Cost of Ownership

8.0/10 · 25%

Computed cost per gallon vs the format-class median. The number nobody surfaces.

  • +8Cost per gallon vs class median A$0.031/gal (bottom 20% of class (cheapest to run)) - Computed cost per gallon scored against the format-class median.

Certification Independence

8.0/10 · 15%

Certified on the official database vs self-claimed 'tested to' marketing.

  • +5Certifications verifiable on official database A3 listings - Certifications are listed on the official NSF/WQA/IAPMO database, not just a logo.
  • +3Per-contaminant reduction disclosed Bperformance data sheet - Publishes percent reduction per contaminant at rated capacity.
  • ·Marketing exceeds certified scope Aclaims beyond certified scope - Marketing emphasizes contaminants the certifications do not cover.

Capacity & Flow Fit

10.0/10 · 15%

Cartridge life and flow appropriate to the format.

  • +3Cartridge life fits the format B1600 gal (norm 500) - Rated cartridge life is appropriate for this filter format.
  • +3Flow / storage disclosed and adequate B2 gpm - Flow rate or RO storage is disclosed and adequate for the format.
  • +2Sediment pre-filter present Bsediment pre-filter - Includes a sediment pre-filter for well or hard-water sources.
  • +2Honestly rated filter life Bgallon rating matches typical use - Months claim matches the gallon rating at typical use.

Practical Fit

7.0/10 · 10%

Install, footprint, and source-water readiness.

  • +5Install type disclosed Cdirect-connect under-sink, tool-free twist-in cartridges - Install method and difficulty are disclosed up front.
  • +2Predictable replacement schedule Chonest life rating - Replacement schedule is predictable from the honest gallon rating.

FAQ

What replacement cartridges does the SK99 use and how often?
The three stages (sold as the M3005 set) are replaced roughly every 3 to 6 months, 8 to 12 months, and 12 to 18 months respectively.
Is it hard to install or change filters?
Frizzlife says installation takes under 15 minutes with no plumber, and the twist-in design lets you swap filters quickly without removing the whole housing.

Related guides

This score is our opinion under our published rubric, not a statement of objective fact or a lab test of this product. We score what third-party certifications prove; absence of a certification means we found no verification, not that a product fails to perform. Last reviewed 2026-06-01. Scored under water-v1.0. Prices and certifications are re-verified on a cadence; see the methodology for how each rule fires.