Short answer: match the standard to the contaminant. NSF/ANSI 42 covers chlorine taste and odor, NSF/ANSI 53 covers health claims such as lead and cysts, and NSF/ANSI 58 covers reverse osmosis, including nitrate. EPA’s April 2024 PFAS fact sheet tells shoppers to look for NSF/ANSI 53 or 58 for PFOA and PFOS. Hardness is none of these: it needs a softener under NSF/ANSI 44.

Answer three questions below. Each result names a filter type and an exact model with the claims in its listing. This is desk research from performance data sheets and certifier listings. Better Water Guide has not tested these products.

Finder

Which water filter fits what you want removed?

Pick the contaminant, where the water is treated and whether you own or rent. The result names a filter type and certified models, or says plainly when no filter on this page fits.

Every option in this finder

As an Amazon Associate, we earn from qualifying purchases.

PickBest forOn Amazon
PUR PLUS 7-cup pitcher (PPT711 series, PPF951K filter)Pitcher filter, no installation. PUR's performance data sheet lists NSF/ANSI 42 chlorine taste and odor reduction (97.5%) and, certified by WQA under NSF/ANSI 53, lead reduction (99.4% at pH 8.5). GuidePUR PLUS 7-cup pitcher
ZeroWater 10-cup pitcher (ZP-010)Pitcher filter, no installation. IAPMO R&T certifies it under NSF/ANSI 53 for lead, mercury, PFOA, PFOS and hexavalent chromium, with a 15-gallon certified capacity. GuideZeroWater 10-cup pitcher ZP-010
LifeStraw Home Glass 7-cup pitcherPitcher filter, no installation. WQA lists it under NSF/ANSI 53 for cadmium, copper, cyst, lead, mercury and turbidity. Cyst means protozoan parasites such as Giardia, not bacteria or viruses. GuideLifeStraw Home Glass 7-cup pitcher
Aquasana Claryum 3-Stage Max Flow AQ-6300MUnder-sink carbon filter with its own faucet. Aquasana's performance data sheet lists NSF/ANSI 42 chlorine reduction (97.3%), NSF/ANSI 53 lead, PFOA and PFOS (99.7%) and cyst reduction, rated 800 gallons at 0.72 gpm. GuideAquasana AQ-6300M
Aquasana SmartFlow reverse osmosis AQ-SFRO2Under-sink reverse osmosis. Aquasana's performance data sheet lists NSF/ANSI 58 nitrate/nitrite reduction (78% overall; up to 27 mg/L nitrate plus 3 mg/L nitrite as N), plus NSF/ANSI 53 lead and PFOA/PFOS and NSF/ANSI 42 chlorine. Daily production in the certification is 25.7 gallons. GuideSearch Amazon for Aquasana AQ-SFRO2
Aquasana Rhino WH-1000 whole-house systemWhole-house carbon and KDF tank rated 1,000,000 gallons at 7.0 gpm. Aquasana says it was independently tested to NSF/ANSI 42 for chlorine. WQA certifies the tank for materials safety only, not for contaminant reduction, so treat chlorine as a maker test result. GuideSearch Amazon for Aquasana Rhino WH-1000
3M Aqua-Pure AP904 whole-house cartridge systemSingle quick-change cartridge. NSF's directory listing (checked October 5, 2026) shows NSF/ANSI 42 chlorine reduction and taste and odor reduction, 100,000 gallons. Its listed claims are aesthetic, with no lead or PFAS claim. Guide3M Aqua-Pure AP904
Aquasana HealthShield WH-HS whole-house systemWhole-house carbon tank. WQA lists it under NSF/ANSI 53 for PFOA, PFOS, PFHxS, PFNA and PFHpA, rated 165,000 gallons at 5.7 gpm. GuideSearch Amazon for Aquasana HealthShield WH-HS
No certified whole-house lead or nitrate filter found hereWe found no whole-house system with a certified lead or nitrate claim that we could verify. For lead, filter the kitchen tap with an NSF/ANSI 53 lead-certified filter. For nitrate, EPA says carbon filters do not remove it; reverse osmosis certified to NSF/ANSI 58 is the point-of-use route. Test first. Guide
Nitrate needs reverse osmosis, which a renter usually cannot installPitchers and carbon filters are not nitrate filters. Ask your landlord about a certified reverse osmosis unit, and get a lab nitrate test first, especially for well water. Guide
Hardness needs a softener, not a filterCartridge filters do not remove calcium and magnesium. EPA's WaterSense guide points to water softeners certified to NSF/ANSI 44. Whole-house sizing and upkeep are covered on our softener page. Guide
Whole-house filters are not the route for bacteria or parasitesA cartridge filter is not a disinfectant. EPA lists NSF/ANSI 55 UV systems for inactivating bacteria and viruses. If a lab or your utility found bacteria, follow that notice. NSF/ANSI 53 cyst claims cover parasites such as Giardia, which is why the drinking-water filters above are the ones to look at. Guide
Whole-house systems are installed on the main water lineSolventum describes the AP900 whole-house series as installed on the main cold-water line, which a renter usually cannot change. Use a pitcher filter instead, or ask your landlord before any install. Guide

Contaminant, standard, filter type and certified models

You want removed Standard to look for Filter type Example models and what the listing says
Chlorine taste and odor NSF/ANSI 42 Carbon pitcher, under-sink carbon, whole-house carbon PUR PLUS pitcher with PPF951K filter (97.5% chlorine, PUR data sheet). Aquasana AQ-6300M under-sink (97.3% free chlorine). Whole house: Aquasana Rhino WH-1000 (maker-tested to NSF/ANSI 42; WQA certifies the tank for materials only) and 3M Aqua-Pure AP904 (NSF listing, checked October 5, 2026).
Lead NSF/ANSI 53 Pitcher, under-sink, reverse osmosis PUR PLUS with PPF951K (99.4% at pH 8.5, WQA). ZeroWater ZP-010 (IAPMO R&T). Aquasana AQ-6300M and AQ-SFRO2 (WQA). No whole-house system with a verified lead claim.
PFAS (PFOA and PFOS) NSF/ANSI 53 or 58 (per EPA) Carbon, reverse osmosis, ion exchange ZeroWater ZP-010 (IAPMO R&T). Aquasana AQ-6300M and AQ-SFRO2 (99.7%). Whole house: Aquasana HealthShield WH-HS (PFOA, PFOS, PFHxS, PFNA, PFHpA).
Nitrate and nitrite NSF/ANSI 58 Reverse osmosis Aquasana AQ-SFRO2 (78% overall nitrate/nitrite reduction; EPA says carbon filters do not remove nitrates).
Cysts (Giardia, Cryptosporidium) NSF/ANSI 53 Pitcher, under-sink LifeStraw Home Glass pitcher (WQA lists cyst). Aquasana AQ-6300M (99.995% cyst).
Bacteria and viruses NSF/ANSI 55 (UV) UV system No model here. EPA names UV under NSF/ANSI 55; follow your utility or lab notice.
Hardness NSF/ANSI 44 Water softener, not a filter See our softener picks .

How this tool decides

Each result requires the contaminant and the treatment point you chose, then ranks by whether you own or rent. Claims come from the performance data sheet or the certifier’s listing for the exact model, and the result says where a claim is the maker’s own. We used the standards EPA names for PFAS, NSF/ANSI 53 and 58, and could not open NSF’s own page for P473, so the table does not use that protocol. Certification covers the listed claims at the tested conditions, not every contaminant. Test your water or read your utility’s report before you choose. Our certification guide shows how to check a listing.

Sources