# Well & Tap

> Independent US consumer research on home water treatment. A database of 56 whole-house water filters, water softeners, salt-free conditioners, UV systems and reverse osmosis units, each graded A to F on independent certification (NSF, IAPMO, WQA, CSA listings), 10-year cost, flow, warranty and returns. Also a lookup of final EPA UCMR 5 PFAS results for 10,313 US public water systems by ZIP code. Not a government website. Earns affiliate commissions; commission is not an input to any grade.

Key facts (September 2026):
- EPA's final UCMR 5 data (released August 2026) covers 10,313 public water systems. 3,595 had at least one PFAS detected; 1,165 averaged above at least one EPA PFAS limit at a sampling point, serving about 55 million people.
- EPA limits (April 2024 rule): PFOA 4 ppt, PFOS 4 ppt, PFHxS, PFNA and GenX 10 ppt each, hazard index 1. In May 2026 EPA proposed keeping only PFOA and PFOS and moving the deadline from 2029 to 2031; the 2024 limits stand until that is final.
- Of 56 systems in the database, 19 hold a system-level certification from NSF, IAPMO, WQA or CSA. "Tested to NSF standards" is not a certification.
- Grades: certification evidence 30%, 10-year cost 25%, flow 15%, warranty 15%, returns 15%. Method: https://wellandtap.com/methodology/

## Tools and data
- [System finder](https://wellandtap.com/filters/): filter all 56 systems by contaminant, water source, certification and price
- [Compare tool](https://wellandtap.com/compare-tool/): side-by-side comparison of up to four systems
- [PFAS lookup by ZIP code](https://wellandtap.com/pfas/): final EPA UCMR 5 results for every tested water system
- [PFAS results by state](https://wellandtap.com/pfas/states/)
- [PFAS data download (CSV)](https://wellandtap.com/data/pfas-by-water-system.csv): one row per water system
- [Product data (JSON)](https://wellandtap.com/data/products.json): every system with grades, prices and certifications
- [Certification standards explained](https://wellandtap.com/certifications/)
- [Calculators](https://wellandtap.com/tools/): flow-rate sizing and 10-year cost

## Best picks
- [The best whole house water filters](https://wellandtap.com/best/whole-house-water-filters/): Whole house water filter picks for city water, wells and PFAS, judged on certification listings, flow and 10-year cost. Prices checked September 2026.
- [The best whole house water filters for well water](https://wellandtap.com/best/whole-house-water-filter-for-well-water/): Well water systems sorted by problem: iron, manganese and sulfur, bacteria, hardness and sediment. Test first, then match the system. Prices checked September 2026.
- [The best whole house water filters for PFAS](https://wellandtap.com/best/whole-house-water-filter-for-pfas/): Which whole house PFAS filters are actually certified, for which compounds and at what flow, and why a certified RO is often the smarter buy. Checked September 2026.
- [The best whole house water filters for city water](https://wellandtap.com/best/whole-house-water-filter-for-city-water/): Whole house filters for chlorine and chloramine city water, judged on media, flow, certification and 10-year cost, with chloramine explained. Checked Sept 2026.
- [The best salt free water softeners](https://wellandtap.com/best/salt-free-water-softener/): Salt-free conditioners reduce scale but leave hardness in your water. Our picks, their inlet limits and 10-year costs, and when a salt softener is the better answer.

## Reviews
- [SpringWell CF1 review](https://wellandtap.com/reviews/springwell-cf1/): SpringWell CF1 review: a 9 gpm city-water carbon tank at about $2,450 over 10 years installed. No NSF, IAPMO or WQA listing, so its PFAS claim is unverified.
- [SpringWell WS1 review](https://wellandtap.com/reviews/springwell-ws1/): SpringWell WS1 review: air-injection iron, sulfur and manganese filter for wells, about $3,220 over 10 years installed. Limits, backwash water use, no certification.
- [US Water Systems Matrixx catalytic carbon review](https://wellandtap.com/reviews/us-water-systems-matrixx/): US Water Systems Matrixx review: self-backwashing catalytic carbon for chloramine, about $2,730 over 10 years for the 10 gpm size. No system certification.
- [Aquasana Rhino review](https://wellandtap.com/reviews/aquasana-rhino/): Aquasana Rhino review: $999 city-water filter, not certified for any contaminant, 23 psi pressure drop on its data sheet, about $2,940 over 10 years installed.
- [Aquasana HealthShield review](https://wellandtap.com/reviews/aquasana-healthshield/): Aquasana HealthShield review: WQA-certified for five PFAS, but a $1,749 tank every 165,000 gallons puts 10 years at $11,000 to $14,500. Who should pay that.
- [Crystal Quest SMART whole house filter review](https://wellandtap.com/reviews/crystal-quest-whole-house/): Crystal Quest SMART review: multimedia backwashing tank from $1,791, about $3,900 over 10 years installed. No system certification, 1-year warranty, NSF mark notice.
- [AquaTru Classic review](https://wellandtap.com/reviews/aquatru-classic/): AquaTru Classic review: $475 countertop RO with IAPMO certifications to NSF/ANSI 42, 53, 58 and 401, about $1,640 over 10 years. When it beats a whole-house filter.

## Comparisons
- [SpringWell vs Aquasana](https://wellandtap.com/compare/springwell-vs-aquasana/): SpringWell CF1 vs Aquasana Rhino, WS1 vs Rhino Well Water with UV, and where HealthShield fits for PFAS: certifications, flow, returns and 10-year cost.
- [SpringWell vs US Water Systems](https://wellandtap.com/compare/springwell-vs-us-water-systems/): SpringWell CF1, WS1 and FS1 against US Water Systems Matrixx, InFusion and GreenWave: flow, certifications, 10-year cost and restocking fees of 10% vs up to 40%.
- [iSpring vs SpringWell](https://wellandtap.com/compare/ispring-vs-springwell/): iSpring WGB32B and WGB32BM cartridge systems vs SpringWell CF1 and WS1 tanks: upfront and 10-year cost, flow, pressure drop, certifications and who each one suits.
- [Whole house water filter vs reverse osmosis](https://wellandtap.com/compare/whole-house-filter-vs-reverse-osmosis/): A whole-house filter treats every tap for chlorine and well problems; reverse osmosis cleans drinking water of PFAS, lead and nitrate. Costs, and when to buy both.

## Contaminants
- [Chlorine](https://wellandtap.com/contaminants/chlorine/): Chlorine in tap water is considered safe up to EPA's 4 mg/L limit. Where it comes from, how to test it, and which certified filters remove its taste and smell.
- [Chloramine](https://wellandtap.com/contaminants/chloramine/): Chloramine is safe to drink up to EPA's 4 mg/L limit but harder to filter than chlorine. How to tell if your utility uses it, and which filters actually remove it.
- [PFAS](https://wellandtap.com/contaminants/pfas/): EPA's limit for PFOA and PFOS is 4 parts per trillion. What PFAS are, the 2026 rule changes, how to check your water, and which certified filters reduce them.
- [Lead](https://wellandtap.com/contaminants/lead/): EPA's health goal for lead in water is zero, and no safe level is known for children. Where lead comes from, how to test it, and which certified filters remove it.
- [Iron](https://wellandtap.com/contaminants/iron/): Iron above EPA's 0.3 mg/L guideline stains fixtures and tastes metallic but is not usually a health risk. How to test it and which treatment fits your iron level.
- [Manganese](https://wellandtap.com/contaminants/manganese/): Manganese stains black above 0.05 mg/L, and EPA advises infants avoid water above 0.3 mg/L. Health effects, stricter state and WHO values, testing and treatment.
- [Hydrogen sulfide](https://wellandtap.com/contaminants/hydrogen-sulfide/): Hydrogen sulfide gives well water a rotten egg smell long before it reaches harmful levels. How to find the source, how to test, and which treatment fits each level.
- [Hardness](https://wellandtap.com/contaminants/hardness/): Hard water is calcium and magnesium: no health risk, but scale, spots and poor lather. How hardness is measured, when to treat it, and softener vs salt-free options.
- [Bacteria](https://wellandtap.com/contaminants/bacteria/): Coliform in a well shows a path for contamination; E. coli means fecal contamination. How to test each year, what to do if positive, and when UV makes sense.
- [Sediment](https://wellandtap.com/contaminants/sediment/): Sand, silt and grit wear out pumps and valves and can shield germs from disinfection. What causes sediment, when it signals a well problem, and how to filter it.
- [Volatile organic compounds (VOCs)](https://wellandtap.com/contaminants/vocs/): VOCs such as benzene, TCE and PCE come from fuel, solvents and dry cleaners. EPA limits, why showers matter too, and which carbon filters reduce them.
- [Arsenic](https://wellandtap.com/contaminants/arsenic/): Arsenic occurs naturally in wells across much of the US and has no taste or smell. EPA's limit is 10 µg/L. How to test, which form you have, and what removes it.
- [Nitrate](https://wellandtap.com/contaminants/nitrate/): Nitrate above EPA's 10 mg/L limit can make infants under six months seriously ill. Where it comes from, why boiling makes it worse, how to test and what removes it.
- [Fluoride](https://wellandtap.com/contaminants/fluoride/): Fluoride is added to many city supplies at 0.7 mg/L and occurs naturally in some wells. EPA's 4.0 mg/L limit is under review. How to test it and what removes it.
- [Copper](https://wellandtap.com/contaminants/copper/): Copper in tap water comes mostly from corroding pipes and leaves blue-green stains. EPA's action level is 1.3 mg/L. Health effects, how to test and how to stop it.
- [Uranium](https://wellandtap.com/contaminants/uranium/): Uranium occurs naturally in some bedrock wells and can harm the kidneys. EPA's limit is 30 µg/L. How to test, and why reverse osmosis at one tap is usually enough.

## Treatment methods
- [Sediment filters](https://wellandtap.com/treatment/sediment/): Sediment filters strain sand, silt and rust out of water to protect fixtures and equipment behind them. What micron ratings mean, what they miss and upkeep costs.
- [Activated carbon](https://wellandtap.com/treatment/activated-carbon/): Activated carbon removes chlorine, taste and odor, many VOCs and long-chain PFAS. What it misses, which NSF standards to check and what carbon systems cost to run.
- [Catalytic carbon](https://wellandtap.com/treatment/catalytic-carbon/): Catalytic carbon is surface-treated activated carbon that breaks down chloramine and hydrogen sulfide faster than standard carbon. Where it fits, limits and costs.
- [KDF (copper-zinc media)](https://wellandtap.com/treatment/kdf/): KDF is a copper-zinc media that reduces chlorine and is sold for iron and hydrogen sulfide. What evidence backs it, what it misses and why it is paired with carbon.
- [Air injection oxidation (AIO)](https://wellandtap.com/treatment/air-injection-oxidation/): Air injection filters oxidize iron, manganese and hydrogen sulfide in well water with no chemicals, then backwash. Working ranges, drain and power needs and costs.
- [Chemical injection (chlorine, peroxide and soda ash)](https://wellandtap.com/treatment/chemical-injection/): A metering pump feeds chlorine, hydrogen peroxide or soda ash into well water to disinfect, oxidize iron and sulfur or raise pH. How it works, upkeep and costs.
- [Ion exchange water softening](https://wellandtap.com/treatment/ion-exchange-softening/): Salt-based softeners swap calcium and magnesium for sodium to make soft water. What else they remove, what they miss, NSF/ANSI 44, salt use and installed costs.
- [Salt-free conditioning](https://wellandtap.com/treatment/salt-free-conditioning/): Salt-free conditioners, usually TAC media, reduce scale without removing hardness. What the test standards measure, feed-water limits and what they cost to own.
- [Ultraviolet (UV) disinfection](https://wellandtap.com/treatment/uv/): UV lamps inactivate bacteria, viruses and cysts without chemicals but remove nothing else. NSF/ANSI 55 Class A vs B, pre-treatment needs, lamp upkeep and costs.
- [Reverse osmosis](https://wellandtap.com/treatment/reverse-osmosis/): Reverse osmosis pushes water through a membrane that holds back PFAS, lead, arsenic, nitrate and fluoride. What it misses, NSF/ANSI 58, water waste and real costs.
- [Specialty media](https://wellandtap.com/treatment/specialty-media/): Specialty media each target one problem: adsorptive media for arsenic, anion resin for nitrate and uranium, activated alumina for fluoride, calcite for acidic water.

## Guides
- [How to remove PFAS from your water](https://wellandtap.com/guides/how-to-remove-pfas-from-water/): Reverse osmosis and activated carbon remove PFAS; boiling does not. What NSF/ANSI 53 and 58 certify, why carbon struggles with short-chain PFAS, and costs.
- [How to test your well water](https://wellandtap.com/guides/how-to-test-well-water/): Test a private well every year for coliform bacteria, nitrate, pH and TDS at a state-certified lab. What else to add, what it costs, and how to read the results.
- [How much a whole house water filter costs](https://wellandtap.com/guides/whole-house-water-filter-cost/): Whole house filters cost $500 to $3,000 to buy, $120 to $600 or more to install and $70 to $1,000 a year to run. Here are 10-year costs by system type.
- [What size whole house water filter you need](https://wellandtap.com/guides/whole-house-water-filter-sizing/): Size a whole house filter by peak flow: gpm by bathroom count, fixture flow rates, main line size, pressure drop and carbon contact time, with worked examples.
- [Iron in well water: what it is and how to remove it](https://wellandtap.com/guides/iron-in-well-water/): Iron above 0.3 mg/L stains fixtures. How to tell ferrous, ferric and bacterial iron apart, and which fix fits: softener, air injection, oxidizing media or chlorine.
- [Why your well water smells like rotten eggs, and how to fix it](https://wellandtap.com/guides/sulfur-smell-in-well-water/): Rotten egg smell is hydrogen sulfide. Hot taps only usually means the water heater anode; all taps means the well. Fixes by level: carbon, air injection, chlorine.
- [Chloramine vs chlorine: which is in your tap water and why it matters](https://wellandtap.com/guides/chloramine-vs-chlorine/): How to tell whether your utility uses chlorine or chloramine, why chloramine needs catalytic carbon and longer contact time, and what it means for dialysis and fish.
- [Salt-free vs salt water softener](https://wellandtap.com/guides/salt-free-vs-salt-water-softener/): A salt softener removes hardness; a salt-free conditioner only changes how it scales. How each is tested, hardness limits, sodium added, costs and when each fits.

## Systems (grade, price, certification)
- [LUMINOR BLACKCOMB 5.1 LB5-101B](https://wellandtap.com/filters/luminor-lb5-101b/): grade A, $897, UV disinfection, certified to NSF/ANSI 55 Class B (listed as LB5-10XB, X = plug type, 13 gpm), CSA B483.1
- [Rheem Preferred RHS32](https://wellandtap.com/filters/rheem-preferred-rhs32/): grade B, $489, Water softener, certified to NSF/ANSI 44, NSF/ANSI 372, CSA B483.1
- [Aqua-Pure (formerly 3M Aqua-Pure, Solventum) AP904](https://wellandtap.com/filters/aqua-pure-ap904/): grade B, $432, Whole-house cartridge system, certified to NSF/ANSI 42
- [Waterdrop G3P800 (WD-G3P800-W)](https://wellandtap.com/filters/waterdrop-g3p800/): grade B, $999, Under-sink reverse osmosis, certified to NSF/ANSI 58, NSF/ANSI 53, NSF/ANSI 42, NSF/ANSI 372
- [AquaTru Carafe (AT100 series)](https://wellandtap.com/filters/aquatru-carafe/): grade B, $375, Countertop reverse osmosis, certified to NSF/ANSI 42, NSF/ANSI 53, NSF/ANSI 58, NSF/ANSI 401, NSF/ANSI 372
- [VIQUA VH410](https://wellandtap.com/filters/viqua-vh410/): grade B, $880, UV disinfection, certified to NSF/ANSI 55 Class B, listed model VH410-V only (with flow restrictor, 14 gpm); the plain VH410 priced here is not the listed model, CSA B483.1, listed model VH410-V only
- [VIQUA Arros 15](https://wellandtap.com/filters/viqua-arros-15/): grade B, $1,046, UV disinfection, certified to NSF/ANSI 55 Class B, listed model Arros 15-V only (with flow restrictor, 9.4 gpm at 16 mJ/cm2 and 70% UVT); the plain Arros 15 priced here is not the listed model, CSA B483.1, listed model Arros 15-V only
- [SpringWell FS1](https://wellandtap.com/filters/springwell-fs1/): grade B, $1,785, Salt-free conditioner, certified to None
- [Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)](https://wellandtap.com/filters/aquasana-smartflow-ro/): grade B, $190, Under-sink reverse osmosis, certified to NSF/ANSI 42, NSF/ANSI 53, NSF/ANSI 58, NSF/ANSI 401, CSA B483.1, NSF/ANSI 372
- [AquaTru Classic (AT2000 series)](https://wellandtap.com/filters/aquatru-classic/): grade B, $475, Countertop reverse osmosis, certified to NSF/ANSI 42, NSF/ANSI 53, NSF/ANSI 58, NSF/ANSI 401, NSF/ANSI 372
- [Pentair FreshPoint GRO-575B (161112)](https://wellandtap.com/filters/pentair-freshpoint-gro-575b/): grade B, $722, Under-sink reverse osmosis, certified to NSF/ANSI 58, NSF/ANSI 53, NSF/ANSI 42, NSF/ANSI 401, CSA B483.1, NSF/ANSI 53, NSF/ANSI 372
- [SpringWell CF1](https://wellandtap.com/filters/springwell-cf1/): grade B, $1,160, Whole-house filter (city water), certified to None
- [Home Master HMF3SdgFeC](https://wellandtap.com/filters/home-master-hmf3sdgfec/): grade B, $550, Whole-house cartridge system, certified to None
- [Pentair FloPlus Protect 20BB (150736)](https://wellandtap.com/filters/pentair-floplus-protect-20bb/): grade B, $325, Whole-house cartridge system, certified to NSF/ANSI 53
- [APEC ROES-50](https://wellandtap.com/filters/apec-roes-50/): grade B, $231, Under-sink reverse osmosis, certified to NSF/ANSI 58, NSF/ANSI 372
- [Home Master TMAFC](https://wellandtap.com/filters/home-master-tmafc/): grade B, $330, Under-sink reverse osmosis, certified to None
- [SpringWell LCR-1](https://wellandtap.com/filters/springwell-lcr1/): grade B, $1,554, Whole-house cartridge system, certified to NSF/ANSI 53
- [Aquasana Rhino WH-1000 (Max Flow WH-1010)](https://wellandtap.com/filters/aquasana-rhino/): grade B, $999, Whole-house filter (city water), certified to None
- [Aquasana Rhino Chloramines WH-1011 (Max Flow WH-1021)](https://wellandtap.com/filters/aquasana-rhino-chloramines/): grade B, $1,399, Whole-house filter (city water), certified to None
- [Waterdrop X16 (WD-X16)](https://wellandtap.com/filters/waterdrop-x16/): grade C, $1,999, Under-sink reverse osmosis, certified to NSF/ANSI 58, NSF/ANSI 42, NSF/ANSI 372
- [SpringWell WS1](https://wellandtap.com/filters/springwell-ws1/): grade C, $2,231, Whole-house filter (well water), certified to None
- [Kind Water Systems S-500](https://wellandtap.com/filters/kind-s-500/): grade C, $1,471, Whole-house filter (city water), certified to None
- [Culligan WH-HD200-C](https://wellandtap.com/filters/culligan-wh-hd200-c/): grade C, $74, Whole-house cartridge system, certified to None
- [iSpring RCC7AK](https://wellandtap.com/filters/ispring-rcc7ak/): grade C, $242, Under-sink reverse osmosis, certified to NSF/ANSI 58
- [Aquasana HealthShield WH-HS](https://wellandtap.com/filters/aquasana-healthshield/): grade C, $2,099, Whole-house filter (city water), certified to NSF/ANSI 53, NSF/ANSI 401, CSA B483.1
- [Kind Water Systems E-1000](https://wellandtap.com/filters/kind-e-1000/): grade C, $976, Whole-house cartridge system, certified to None
- [Kind Water Systems E-2000](https://wellandtap.com/filters/kind-water-e-2000/): grade C, $1,353, Salt-free conditioner, certified to None
- [SpringWell CSF1](https://wellandtap.com/filters/springwell-csf1/): grade C, $2,321, Whole-house filter (city water), certified to None
- [SpringWell WSSS1](https://wellandtap.com/filters/springwell-wsss1/): grade C, $3,124, Whole-house filter (well water), certified to None
- [AquaTru Freestanding Model 1 (ATFS-1-W)](https://wellandtap.com/filters/aquatru-freestanding-model-1/): grade C, $1,699, Countertop reverse osmosis, certified to NSF/ANSI 42, NSF/ANSI 53, NSF/ANSI 58, NSF/ANSI 401
- [US Water Systems GreenWave 2.0 (385-GW)](https://wellandtap.com/filters/us-water-systems-greenwave/): grade C, $1,361, Salt-free conditioner, certified to None
- [RKIN CS8 / CS9 / CS10 / CS13](https://wellandtap.com/filters/rkin-cs-whole-house-carbon/): grade C, $938, Whole-house filter (city water), certified to None
- [SoftPro Whole House Chlorine+ Filter (upflow catalytic carbon)](https://wellandtap.com/filters/softpro-chlorine-plus-upflow-carbon/): grade C, $917, Whole-house filter (city water), certified to None
- [AFWFilters WS48-56SXT (Fleck 5600SXT, 48,000 grain)](https://wellandtap.com/filters/afwfilters-fleck-5600sxt-48k/): grade C, $765, Water softener, certified to None
- [SoftPro Iron Master AIO](https://wellandtap.com/filters/softpro-iron-master-aio/): grade C, $1,517, Whole-house filter (well water), certified to None
- [SpringWell PFS-1](https://wellandtap.com/filters/springwell-pfs1/): grade C, $2,910, Whole-house cartridge system, certified to None
- [Aquasana Salt-Free Water Conditioner WH-SFWC-S](https://wellandtap.com/filters/aquasana-salt-free-conditioner/): grade C, $879, Salt-free conditioner, certified to None
- [US Water Systems Pioneer (Enpress CTA0840BBBKP5-04C00)](https://wellandtap.com/filters/us-water-systems-pioneer-pfas/): grade C, $1,669, Whole-house cartridge system, certified to NSF/ANSI 53 (lead, cyst, PFOA/PFOS), NSF P473 (PFOA, PFOS), CSA B483.1
- [SpringWell SS1](https://wellandtap.com/filters/springwell-ss1/): grade C, $1,607, Water softener, certified to None
- [Aquasana Rhino Well Water with UV WH-WELL-UVS (WH-WELL-UV)](https://wellandtap.com/filters/aquasana-rhino-well-water-uv/): grade C, $1,749, Whole-house filter (well water), certified to None
- [Watts OneFlow+ OFPSYS](https://wellandtap.com/filters/watts-oneflow-plus-ofpsys/): grade C, $829, Salt-free conditioner, certified to NSF/ANSI 372 (lead-free materials only)
- [SpringWell SPRW-UV-15gpm](https://wellandtap.com/filters/springwell-uv/): grade C, $1,101, UV disinfection, certified to None
- [SoftPro Elite HE (city water, upflow)](https://wellandtap.com/filters/softpro-elite/): grade C, $1,367, Water softener, certified to None
- [US Water Systems Pulsar UV (405-PUV-200)](https://wellandtap.com/filters/us-water-systems-pulsar-uv/): grade C, $995, UV disinfection, certified to None
- [US Water Systems Matrixx Catalytic Carbon (081-MXF-CX)](https://wellandtap.com/filters/us-water-systems-matrixx-catalytic-carbon/): grade C, $1,326, Whole-house filter (city water), certified to None
- [US Water Systems Flexx Oxi-Gen (081-FX)](https://wellandtap.com/filters/us-water-systems-flexx-oxi-gen/): grade C, $2,230, Whole-house filter (well water), certified to None
- [AFWFilters Iron Pro 2 fine mesh softener (Fleck 5600SXT)](https://wellandtap.com/filters/afwfilters-iron-pro-2/): grade C, $755, Water softener, certified to None
- [AFWFilters Air Injection Titanium 10 (AIT10-25SXT)](https://wellandtap.com/filters/afwfilters-air-injection-titanium/): grade C, $1,289, Whole-house filter (well water), certified to None
- [US Water Systems Matrixx InFusion (081-MIF)](https://wellandtap.com/filters/us-water-systems-matrixx-infusion/): grade C, $2,983, Whole-house filter (well water), certified to None
- [iSpring WGB32B](https://wellandtap.com/filters/ispring-wgb32b/): grade D, $517, Whole-house cartridge system, certified to None
- [Crystal Quest Metal Removal Whole House Water Filter (CQE-WH-01195)](https://wellandtap.com/filters/crystal-quest-metal-removal-whole-house/): grade D, $1,331, Whole-house filter (well water), certified to None
- [US Water Systems Flexx InFusion (081-FIF)](https://wellandtap.com/filters/us-water-systems-flexx-infusion/): grade D, $2,255, Whole-house filter (well water), certified to None
- [iSpring WGB32BM](https://wellandtap.com/filters/ispring-wgb32bm/): grade D, $536, Whole-house cartridge system, certified to None
- [Express Water WH300SCKS](https://wellandtap.com/filters/express-water-wh300scks/): grade D, $548, Whole-house cartridge system, certified to None
- [Crystal Quest SMART Whole House Water Filter (CQE-WH-01114)](https://wellandtap.com/filters/crystal-quest-smart-whole-house/): grade D, $1,791, Whole-house filter (city water), certified to None
- [Aquasure Harmony Series (AS-HS32D / AS-HS48D / AS-HS64D)](https://wellandtap.com/filters/aquasure-harmony/): grade D, $540, Water softener, certified to None

## Optional
- [Full text for AI assistants](https://wellandtap.com/llms-full.txt)
- [About](https://wellandtap.com/about/), [How we rate](https://wellandtap.com/methodology/), [Affiliate disclosure](https://wellandtap.com/affiliate-disclosure/), [Contact](https://wellandtap.com/contact/)