Home Water HQWater filtration, honestly graded — every price verified, every certification decoded, every yearly filter cost published.

Water filtration, honestly graded

Build your water system. Every part checked against every other part.

The builder below assembles a stage-by-stage system (sediment, iron, softener, main filtration, UV, drinking-water RO) from what your water test flags — checking flow rates, connection sizes, and stage order against the manufacturers' published specs — and hands you one priced build sheet to buy on Amazon. Shopping for a single filter instead? The contaminant finder ranks all 39 products in our dataset by certified coverage.

By the Home Water HQ research desk · Updated November 2026 · Prices verified 2026-11-03 · Certification data verified 2026-11-05 · How we work

Our top picks

The four systems we'd point a friend to first — one per way of filtering, each with paperwork that matches its marketing.

Best whole-house

B

Aquasana Rhino WH-1000

Tested to NSF/ANSI 42 — not certified

The whole-house chlorine benchmark — independently tested to NSF/ANSI 42 (97% over a million gallons). Tested, not certified.

Independently tested to NSF/ANSI 42 (97% chlorine)1,000,000-gallon media life7 GPM suits ~2.5 baths max

7.0 GPM rated flow; 1,000,000 gal media life
Filters: ~$75 (pre/post filters)/yr · Paperwork grade B (our rubric)

$1,998

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Best under-sink

A

Waterdrop G3P800

Whole-system certified

The premium tankless benchmark — 800 GPD, a smart faucet, and IAPMO certification that includes PFAS.

IAPMO 42/53/58 incl. PFASFast: 800 GPD, 3:1 drain ratio~$160/yr filters

800 GPD tankless; 3:1 pure-to-drain; built-in UV; smart faucet shows TDS
Filters: ~$160 (manufacturer figure)/yr · Paperwork grade A (our rubric)

$849~~$999~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Best countertop

A

AquaTru Classic

Whole-system certified

The certification leader of countertop RO: independently certified for 84 contaminants, PFAS included.

Strongest countertop certification (incl. P473 PFAS)No plumbingPremium ticket; batch tank

4-stage countertop RO; no plumbing; ~0.75 gal batch tank
Filters: ~$100 (1-yr combo pack $99.85); ~$130/yr averaged incl. membrane year/yr · Paperwork grade A (our rubric)

$475

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Best certified value

A

APEC RO-90

Whole-system certified

The best certified value in RO — a broad WQA claim list (fluoride, chromium-6, lead) at a budget price.

Broadest certified claims per dollarAssembled in the USATank system — slower glass fills

90 GPD; 4-gallon tank; no electricity
Filters: ~$60-75/yr · Paperwork grade A (our rubric)

$264.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

The 20-second tool

Find your filter

Where? Main concern? Budget?

How we grade. Every product gets a paperwork grade (A–C) from a published rubric: whole-system performance certification with named contaminants earns the top; narrow scopes (TDS-only, taste-and-odor) land in the middle; component-only, materials-only, or lab-test-only claims land at the bottom — whatever the box says. Prices are pulled from manufacturer and retailer pages and dated in our open dataset. Yearly filter cost is computed from the manufacturer's own replacement schedule. Full rubric: NSF certifications explained.

Whole-house tank systems

Whole-house tank systems

Every product graded. Full guide: Whole-house tank systems guide

B

Aquasana Rhino WH-1000

Tested to NSF/ANSI 42 — not certified

7.0 GPM rated flow; 1,000,000 gal media life
Filters: ~$75 (pre/post filters)/yr

$1,998

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B+

Whirlpool WHELJ1

Certified — taste & odor (42)

6 GPM service flow; ~570,000 gal media life; self-cleaning every 14 days
Filters: $0 (no filters to replace for the life of the unit)/yr

$399

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

SpringWell CF1

Components certified — system is not

9 GPM (1-3 bathrooms); 1,000,000 gal media life
Filters: ~$40 (sediment post-filter)/yr

$1,160.25~~$1,365~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Kind Water Systems E-1000

Materials-only certification

15 GPM; ~80,000 gal per cartridge set
Filters: ~$120-300 (annual cartridge set)/yr

$976.46

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Whole-house cartridge systems & housings

Whole-house cartridge systems & housings

Every product graded. Full guide: Whole-house cartridge systems & housings guide

C

iSpring WGB32B-PB

No verified certification

Up to 15 GPM; 100,000 gal capacity (lead cartridge 150,000 gal)
Filters: ~$110 (cartridge set)/yr

$465.22

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C

Express Water 3-Stage Whole House (Heavy Metals)

No verified certification

100,000 gal per filter set; flow rate not stated by manufacturer
Filters: —/yr

$449.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Pentair Pentek Big Blue 150237

Housing certified NSF/ANSI 42 — the cartridge does the filtering

HOUSING ONLY — not a complete filter system. 1 in ports with pressure relief; pressure drop is just 1 psi at 15 GPM (Pentair spec sheet).
Filters: —/yr

$66

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Pentair Pentek DGD-5005

NSF/ANSI 42 materials only

Dual-gradient polypropylene sediment cartridge, 50 micron outer to 5 micron core, 10 in × 4.5 in
Filters: —/yr

$24.29

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Under-sink reverse osmosis

Under-sink reverse osmosis

Every product graded. Full guide: Under-sink reverse osmosis guide

A

Waterdrop G3P800

Whole-system certified

800 GPD tankless; 3:1 pure-to-drain; built-in UV; smart faucet shows TDS
Filters: ~$160 (manufacturer figure)/yr

$849~~$999~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

A

APEC RO-90

Whole-system certified

90 GPD; 4-gallon tank; no electricity
Filters: ~$60-75/yr

$264.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B+

Waterdrop G3P600

Certified — 42/53/58/372 (IAPMO)

600 GPD tankless; 2:1 pure-to-drain; smart display faucet
Filters: ~$145 (manufacturer figure)/yr

$439~~$539~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B

iSpring RCC7AK

Certified — TDS scope only

75 GPD; 3.2-gallon tank; no electricity
Filters: ~$62 (standard-size filters)/yr

$239.99~~$241.99~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B

APEC ROES-50

Certified — TDS scope only

50 GPD; 4-gallon tank; no electricity
Filters: ~$55/yr

$230.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B-

Express Water RO5DX

Certified — TDS scope only

50 GPD rated; 4-gallon tank; no electricity
Filters: ~$37-66/yr

$167.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Frizzlife PD600-TAM3

Manufacturer-stated; listing unconfirmed

600 GPD tankless; 2:1 pure-to-drain; real-time TDS display
Filters: ~$60-80 (per review sites)/yr

$399.99~~$469.99~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Countertop filters

Countertop filters

Every product graded. Full guide: Countertop filters guide

A

AquaTru Classic

Whole-system certified

4-stage countertop RO; no plumbing; ~0.75 gal batch tank
Filters: ~$100 (1-yr combo pack $99.85); ~$130/yr averaged incl. membrane year/yr

$475

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B-

Frizzlife WB99-C

Membrane certified, not the system

Countertop RO; 100 GPD; 3.5:1 pure-to-drain; alkaline post-filter
Filters: ~$130-146 (the highest in countertop RO — the alkaline post-filter is replaced quarterly)/yr

$389.99~~$449.99~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B+

AquaTru Carafe

Whole-system certified

4-stage countertop RO with glass carafe; 1-2 person households
Filters: ~$80-100 (1-yr combo pack)/yr

$375

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B

Waterdrop K19 (WD-K19-H/S)

Certified — TDS scope only

6-stage countertop RO dispenser; 75 GPD; 3:1 pure-to-drain; instant hot on K19-H
Filters: ~$69-75 (single $68.99 cartridge, once a year — the cheapest countertop RO consumable)/yr

$279~~$379~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B-

Big Berkey with Phoenix Elements

Certified — 42 + 372 only

2.25 gal gravity system; up to 5,500 gal per element set (~$0.02/gal)
Filters: ~$13-50 (multi-year element life — the anti-subscription product)/yr

$267

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Bluevua RO100ROPOT

Certification scope unverified

5-stage countertop RO; glass carafe; remineralization; TDS + filter-life monitors
Filters: ~$90 (1-yr set $89.97); ~$110-120 averaged incl. membrane years/yr

$389~~$434~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C

Waterdrop C2SL

No certification listed

7-stage mineral RO; glass pitcher; 75 GPD; 528 gal per filter
Filters: ~$56 (the lowest in countertop RO)/yr

$159.99~~$199.99~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Pitchers & faucet filters

Pitchers & faucet filters

Every product graded. Full guide: Pitchers & faucet filters guide

A-

PUR PLUS Faucet System (PFM400H)

Whole-system certified

Faucet-mount; 100 gal or 3 months per filter; filter-change light
Filters: ~$55-79 (cheaper in multipacks)/yr

$39.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

A-

Brita Denali Pitcher with Elite Filter

Whole-system certified

6-cup pitcher; Elite filter lasts 120 gal / ~6 months
Filters: ~$40 (the cheapest pitcher consumable — two filters a year)/yr

$35.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B+

Brita Ultramax Dispenser with Elite Filter

Whole-system certified

27-cup dispenser; same Elite filter (120 gal / ~6 months)
Filters: ~$40/yr

$49.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B

PUR PLUS 11-Cup Pitcher

Certified — 42 + 53

11-cup pitcher; filter lasts 40 gal / ~2 months
Filters: ~$70-108 (six filters a year on schedule)/yr

$39.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B-

Culligan ZeroWater 12-Cup Pitcher

Certified — IAPMO listing

5-stage ion-exchange pitcher; includes TDS meter; filters to 000 TDS
Filters: ~$185-240+ (filter life is TDS-dependent: 15-40 gal per filter — the most expensive water per gallon in this dataset)/yr

$36.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Clearly Filtered Pitcher

Certified 42 + 372 only — claims are lab tests

10-cup pitcher; 100 gal per filter; medical-grade Tritan
Filters: ~$156-260 ($65 per filter)/yr

$110

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Fridge & shower filters

Fridge & shower filters

Every product graded. Full guide: Fridge & shower filters guide

A-

everydrop Refrigerator Filter 4 (EDR4RXD1)

Whole-system certified

Replace every 6 months; rated 300 gal
Filters: ~$114-120 (two OEM filters a year)/yr

$57~~$59.99~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B

Aquasana Shower Filter AQ-4100

Tested to NSF 177 — not certified

10,000 gal or 6 months; 2-stage coconut carbon + KDF-55
Filters: $125.98 (two $62.99 cartridges a year)/yr

$79.99~~$139.99~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

B

Waterdrop Filter 4 Replacement (EDR4RXD1 fit, 4-pack)

Certified — narrower than OEM

300 gal / 6 months per filter; fits everydrop Filter 4 fridges
Filters: ~$18 (the OEM-vs-compatible gap is ~6x: ~$120/yr vs ~$18/yr)/yr

$35.69~~$47.99~~

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Water softeners

Water softeners

Every product graded. Full guide: Water softeners guide

B+

Whirlpool WHES40 40,000 Grain Water Softener

NSF/ANSI 44 certified

40,000 grains at maximum salt dose; 7.6 GPM rated service flow (current manual); 1 in connection
Filters: ~$40-60 (salt)/yr

$739

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Fleck 5600SXT 48,000 Grain Water Softener (AFWFilters build)

No verified certification

48,000 grains (1.5 cu ft resin); 12 GPM service flow (stated for this build); 1 in connection
Filters: ~$40-60 (salt)/yr

$775

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C+

Aquasure Harmony 48,000 Grain Water Softener (AS-HS48D)

No verified certification

48,000-grain salt softener; 1 in or 3/4 in connection (select at purchase); no manufacturer service-flow rating (listing maximum 12 GPM)
Filters: ~$40-60 (salt)/yr

$629.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Iron filters

Iron filters

Every product graded. Full guide: Iron filters guide

C+

SpringWell WS1 Whole House Well Water System (iron / sulfur / manganese)

No verified certification

Air-injection oxidation over Greensand Fusion media; 12 GPM service flow; 1 in connection; rated 7 ppm iron / 8 ppm hydrogen sulfide / 1 ppm manganese (manufacturer)
Filters: Media rated 10+ years; sediment pre-filter changes extra/yr

$2,231

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C

AFWFilters Air Injection Platinum 15 (iron / sulfur)

No verified certification

Air injection over 1.5 cu ft Filox (Mang-Ox) media; rated 20 ppm iron / 15 ppm hydrogen sulfide / 6 ppm manganese (seller); 12 GPM peak recommended — no service-flow rating published
Filters: Media life not published/yr

$1,810

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C

iSpring WCFM400K Iron & Manganese Filter

Media certified (NSF 61) — system is not

Air-injection catalytic media (manganese dioxide); 400,000-gal rated capacity; no manufacturer service-flow rating (listing maximum 12 GPM)
Filters: Media life not published by iSpring/yr

$1,417.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

UV disinfection

UV disinfection

Every product graded. Full guide: UV disinfection guide

B-

VIQUA VH410 Whole House UV System

Dose published; validated SKU is the VH410-V

14 GPM at the 40 mJ/cm² dose; 18 GPM at 30 mJ/cm²; 3/4 in - 1 in combo connection; lamp replaced annually
Filters: ~$165-170 (annual lamp)/yr

$880

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

C

iSpring UVF55FS Whole House UV Filter (55W)

No NSF 55 certification

12 GPM maximum; 1 in connection; UV dose NOT published by iSpring; lamp replaced annually
Filters: ~$80 (annual lamp)/yr

$338.99

Manufacturer or retailer price, checked 2026-11-03 — Amazon's price may differ

Guides

Best Whole-House Water Filters

Tank and cartridge systems graded on what they're actually certified to do.

Best Under-Sink RO Systems

Tankless vs tank, and why '50 GPD' usually isn't.

Best Countertop Water Filters

RO without the plumbing — and the yearly filter bills compared.

Best Pitcher Water Filters

The cheapest pitcher to buy is the priciest to own. The numbers inside.

Whole-House vs Under-Sink

Different tools for different problems. Decide by problem, not product.

NSF Certifications Explained

What 'certified' actually means — the four tricks on every box.

What Filters Really Cost Per Year

Every product in our dataset, ranked by the number nobody prints.

Water Filter Sizing Guide

GPM, GPD, and cups per fill — sizing each filter type by demand.

For AI agents: the full dataset — prices, certification scopes, yearly filter costs, buy links — is open at /data/filters.json, with a lite edition at /data/filters-lite.json. Terms: For Agents.