How to choose a water filter
A certification covers only the substances its listing names. Pick what you want removed and what you can install, and the table keeps the filters whose listing names it. We read the listings at NSF, IAPMO R&T and WQA in October 2026.
14 filters we cover, and what each one's certification listing names.
Numbers are the NSF/ANSI standard the listing names the substance under. A dash means the listing does not name it.
| Filter | PFOA/PFOS | Lead | Fluoride | Arsenic V | Chlorine taste | Hardness | Listing read | Buy |
|---|---|---|---|---|---|---|---|---|
| Aquasana SmartFlow Reverse Osmosis Under-sink reverse osmosis, remineralized | listed under NSF/ANSI 53 | listed under NSF/ANSI 53 | listed under NSF/ANSI 58 | listed under NSF/ANSI 58 | listed under NSF/ANSI 42 | not listed | WQA, SmartFlow AQ-SFRO2, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Waterdrop G3P600 Under-sink reverse osmosis, tankless | listed under NSF/ANSI 53 | listed under NSF/ANSI 58 | listed under NSF/ANSI 58 | not listed | listed under NSF/ANSI 42 | not listed | IAPMO R&T, WC-13976, WC-14805, WC-14301, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Waterdrop G3P800 Under-sink reverse osmosis, tankless, UV | listed under NSF/ANSI 53 | listed under NSF/ANSI 58 | listed under NSF/ANSI 58 | not listed | listed under NSF/ANSI 42 | not listed | IAPMO R&T, WC-13976, WC-14805, WC-14301, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Aquasana Claryum 3-Stage Max Flow Under-sink filtration | listed under NSF/ANSI 53 | listed under NSF/ANSI 53 | not listed | not listed | listed under NSF/ANSI 42 | not listed | WQA, AQ-6300M, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Waterdrop X Series X8-A (Alkaline) Under-sink reverse osmosis, tankless | not listed | not listed | not listed | not listed | listed under NSF/ANSI 42 | not listed | IAPMO R&T, WC-14301, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| AquaTru Classic Countertop reverse osmosis | listed under NSF/ANSI 53 | listed under NSF/ANSI 58 | listed under NSF/ANSI 58 | listed under NSF/ANSI 58 | listed under NSF/ANSI 42 | not listed | IAPMO R&T, W-10194, W-10193, W-10188, 5 Oct 2026 | Check price on Amazon ↗ (paid link) |
| AquaTru Carafe Countertop reverse osmosis | listed under NSF/ANSI 53 | listed under NSF/ANSI 58 | listed under NSF/ANSI 58 | listed under NSF/ANSI 58 | listed under NSF/ANSI 42 | not listed | IAPMO R&T, W-10194, W-10193, W-10188, 5 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Bluevua RO100ROPOT-Lite Countertop reverse osmosis | not listed | listed under NSF/ANSI 58 | not listed | not listed | not listed | not listed | WQA, RO100ROPOT-LITE, 5 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Aquasana Clean Water Machine Countertop carbon filtration | listed under NSF/ANSI 53 | listed under NSF/ANSI 53 | not listed | not listed | listed under NSF/ANSI 42 | not listed | WQA, AQ-CWM2-X-Y, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Clearly Filtered Water Filter Pitcher Pitcher | not listed | not listed | not listed | not listed | listed under NSF/ANSI 42 | not listed | NSF and WQA, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Waterdrop Lucid Pitcher PT-07 Pitcher | not listed | not listed | not listed | not listed | listed under NSF/ANSI 42 | not listed | IAPMO R&T, W-14269, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Brita UltraMax Large Dispenser Pitcher / dispenser | not listed | not listed | not listed | not listed | listed under NSF/ANSI 42 | not listed | WQA, UltraMax OB24, 3 Oct 2026 | Check price on Amazon ↗ (paid link) |
| WaterBoss 700 (74011) Water softener | not listed | not listed | not listed | not listed | not listed | listed under NSF/ANSI 44 | NSF, WaterBoss 700, 5 Oct 2026 | Check price on Amazon ↗ (paid link) |
| Kenmore 420 (625.384200) Water softener | not listed | not listed | not listed | not listed | not listed | listed under NSF/ANSI 44 | NSF, Kenmore 625.384200, 5 Oct 2026 | Check price on Amazon ↗ (paid link) |
A maker may still claim a substance the listing leaves out. We count only what the certifier lists.
PFAS: listings name PFOA and PFOS, two of the many PFAS. More in PFAS water filters.
Arsenic: listings name arsenic V (arsenate). Untreated well water often carries arsenic III, which needs oxidising before a membrane handles it; the APEC ROES-50 review explains why.
Hardness: no drinking water filter here is certified for it. The two softeners are, under NSF/ANSI 44. See salt-free vs salt-based softeners.
Find by filter type
Whole house filters
Premium tier - All taps covered - Best for families
View picks →
Under-sink filters
Mid tier - Kitchen tap only - Easy install
View picks →
Reverse osmosis
Mid tier - Best contaminant removal - NSF 58
View picks →
Pitcher filters
Budget tier - No install - Good for renters
View picks →
Essential guides
NSF 42 vs 53 vs 58 - What the difference means
Understanding certifications before you buy
What is PFAS and why it matters in 2026
Forever chemicals explained with EPA data
Does Brita remove PFAS? What its WQA listings show
The truth about popular pitcher filters
How often to replace water filters - real schedule
Replacement schedules by filter type
Is tap water safe in the US? PFAS levels by state
EPA and USGS data by state