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iSpring WGB21B

Ranked #13 of 35 in Best Whole-House Water Filters (2026). Here is every spec we scored, where it came from, and how it compares.

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#13

iSpring WGB21B

Best for: 2-stage 10-inch whole-house sediment and CTO filter listed at 15 GPM

2.2/10

What we like

    Watch out for

    • Micron rating not published by iSpring

    Score breakdown

    Filtration stages 22%
    Service or listed flow 30%
    Micron rating * 16%
    NSF/ANSI 42 or 53 named 20%
    Warranty 12%

    * Not published by the manufacturer; scored at the lowest published value in this category, so an unpublished figure never outranks a published one.

    Filtration stages2
    Service or listed flow15 GPM
    Micron ratingNot listed
    NSF/ANSI 42 or 53 namedNo
    Warranty1 yr
    Stages (maker)2 stages (official product name)
    Flow rate (maker)15 GPM (official collection listing)
    Micron rating (maker)Not listed
    NSF/ANSI 42 or 53 (maker)Not listed
    Warranty (maker)1-year manufacturer warranty (official page)
    Filter size (maker)10" x 4.5"
    PriceCheck price
    Check price at Amazon
    Specs source:

    iSpring WGB21B head-to-head

    Head-to-headiSpring WGB31B vs iSpring WGB21B

    How it compares

    Open the full comparison table

    iSpring WGB32B-KSNC
    4.7/10
    #1 · 3-stage 20-inch chloramine and heavy-metals filter; official page names NSF/ANSI 42
    iSpring WCF200K
    3.2/10
    #2 · Elite Series central whole-house filtration system listed at 26 GPM
    Waterdrop WHF2E-FC
    2.8/10
    #3 · 5-stage whole-house filter, model WD-WHF2E-FC
    iSpring WGB32B-PB
    2.7/10
    #4 · 3-stage 20-inch whole-house filter with a lead-reducing cartridge, listed at 15 GPM
    iSpring WGB32BM
    2.7/10
    #5 · 3-stage 20-inch whole-house filter for iron and manganese, listed at 15 GPM
    iSpring WGB31B
    2.7/10
    #6 · 3-stage 10-inch whole-house sediment and carbon-block filter listed at 15 GPM
    iSpring WGB31BC
    2.7/10
    #7 · 3-stage 10-inch whole-house filter with a clear housing, listed at 15 GPM
    iSpring WGB31BCM
    2.7/10
    #8 · 3-stage 10-inch clear-housing filter for iron and manganese, listed at 15 GPM
    iSpring WGB32B
    2.7/10
    #9 · 3-stage 20-inch Big Blue sediment and carbon-block filter listed at 15 GPM
    iSpring WGB32B-KS
    2.7/10
    #10 · 3-stage 20-inch KDF whole-house filter listed at 15 GPM
    Aquasure Fortitude Tri-Stage Iron Removal
    2.7/10
    #11 · Tri-stage whole-house iron system listed at 15 GPM with a 100,000-gallon capacity
    Waterdrop WHF2E-PC
    2.3/10
    #12 · 4-stage whole-house filter; official page names NSF/ANSI 372 only
    Waterdrop WD-WHF21-PG
    2.2/10
    #14 · 2-stage whole-house iron and manganese filter listed at up to 15 GPM and 5 micron
    iSpring WGB21BM
    2.2/10
    #15 · 2-stage 10-inch whole-house filter with an iron and manganese cartridge, listed at 15 GPM
    iSpring WGB22B
    2.2/10
    #16 · 2-stage 20-inch Big Blue sediment and carbon-block filter listed at 15 GPM
    iSpring WGB22BM
    2.2/10
    #17 · 2-stage 20-inch whole-house filter for iron and manganese, listed at 15 GPM
    APEC Whole House Max 20
    1.8/10
    #18 · Heavy-duty whole-house filter listed at 16 GPM service and 20 GPM peak
    Aquasure Fortitude Lite 800,000 Gallons
    1.8/10
    #19 · Fortitude Lite whole-house filter with an official 800,000-gallon capacity and a 5-year limited warranty
    Waterdrop WHF3E-SKH
    1.7/10
    #20 · 3-stage whole-house housing officially described as 9-stage filtration, model WD-WHF3E-SKH
    iSpring WGB12B
    1.6/10
    #21 · 1-stage 20-inch Big Blue whole-house carbon-block filter listed at 15 GPM
    Waterdrop WHF21-PBH
    1.2/10
    #22 · 2-stage whole-house filter with a 5-micron heavy-metal sediment cartridge
    APEC Whole House Max 15
    1.2/10
    #23 · Heavy-duty whole-house filter listed at 12 GPM service and 16 GPM peak
    Aquasure Fortitude V 10-Inch 2-Stage
    1.2/10
    #24 · 2-stage 10-inch whole-house sediment and carbon filter
    Aquasure Fortitude V 20-Inch 2-Stage
    1.2/10
    #25 · 2-stage 20-inch whole-house sediment and carbon filter
    APEC Whole House Max 10
    0.6/10
    #26 · Heavy-duty whole-house filter listed at 8 GPM service and 12 GPM peak
    Waterdrop WHF21-SH
    0.6/10
    #27 · Whole-house well-water filter officially listed at 5 micron
    APEC Green Carbon 10
    0.6/10
    #28 · Whole-house chemical and odor filter in a 9-inch tank
    APEC Green Carbon 15
    0.6/10
    #29 · Whole-house chemical, odor and taste filter in a 10-inch tank
    APEC Iron Hydro 10
    0.6/10
    #30 · Iron, hydrogen sulfide and manganese whole-house filter
    APEC Iron Hydro 15
    0.6/10
    #31 · Larger Iron Hydro filter for iron, hydrogen sulfide and manganese
    APEC Iron Hydro 20
    0.6/10
    #32 · Largest Iron Hydro filter in this official series
    Aquasure Fortitude Pro 1,000,000 Gallons
    0.6/10
    #33 · Fortitude Pro whole-house filter with an official 1,000,000-gallon capacity
    Aquasure Fortitude Pro 1,500,000 Gallons
    0.6/10
    #34 · Fortitude Pro whole-house filter with an official 1,500,000-gallon capacity
    Aquasure Fortitude Pro 600,000 Gallons
    0.6/10
    #35 · Fortitude Pro whole-house filter with an official 600,000-gallon capacity