Water filters, scored
These are the water filters we rate highest, best score first. A filter only earns credit for removing something if we can find it listed on the official NSF, WQA, or IAPMO database - so if a brand says "tested to" a standard rather than "certified to" it, that's not the same thing, and we don't give it the points. The "$/gal" column is what a filter costs you per gallon once you count the cartridges.
| Score | Unit | $/gal |
|---|---|---|
| 8.4 | Brita Elite Pitcher (10-Cup) | $0.167 |
| 7.5 | AquaTru Classic Countertop RO | $0.287 |
| 7.5 | Culligan US-EZ-4 Under-Sink | $0.091 |
| 7.2 | Aquasana AQ-5200 Under-Sink | $0.148 |
| 7.0 | Brita Faucet Mount (FF-100) | $0.180 |
| 6.8 | Frizzlife SK99 Under-Sink Filter | $0.031 |
| 6.6 | Waterdrop G3P800 Tankless RO | $0.123 |
| 6.4 | PUR Plus Faucet Mount (PFM400H) | $0.250 |
| 6.1 | iSpring RCC7 5-Stage RO | $0.024 |
| 5.9 | PUR Plus Pitcher (7-Cup) | $0.374 |
| 5.7 | Waterdrop 10UA Under-Sink | $0.005 |
| 5.6 | Brita Standard Pitcher | $0.200 |
| 4.9 | ZeroWater 5-Stage Pitcher (7-Cup) | $1.167 |
| 4.9 | Express Water RO5DX 5-Stage RO | $0.021 |
| 4.3 | Home Master TMAFC-ERP Artesian RO | $0.038 |
| 4.1 | Epic Smart Shield Under-Sink | $0.177 |
| 4.0 | APEC ROES-50 Essence RO | $0.145 |
| 3.7 | SpringWell CF1 Whole House | $0.000 |
| 3.4 | Aquasana Rhino EQ-1000 Whole House | $0.001 |
| 3.2 | Big Berkey Gravity System | $0.028 |
| 3.2 | Epic Pure Pitcher | $0.353 |
| 2.7 | LifeStraw Home Pitcher | $0.288 |
| 2.5 | Clearly Filtered Pitcher | $0.495 |
| 1.7 | Clearly Filtered 3-Stage Under-Sink | $0.198 |
| 1.5 | Great Value Water Filter Pitcher (HS528N) | n/a |
FAQ
- How are these water filters ranked?
- Best score first. Every score is our opinion under the published water rubric, computed from inputs you can check yourself - the contaminant scope certified on the official NSF, WQA, or IAPMO registries, and the real cost per gallon. The full score-event breakdown is on each scorecard.
- What is the difference between tested to and certified to?
- Certified means the product is listed on the official NSF, WQA, or IAPMO database, where anyone can verify the claim. Tested to a standard is not the same thing - it earns zero certification credit in our scoring, and we label it as uncertified.
- What does the $/gal column mean?
- It is what the filter costs you per gallon once you count the replacement cartridges, computed from real, sourced prices. When we cannot find a real price, the column shows n/a: a missing price is a labeled data gap, not an estimate.
- Why does a filter earn no credit for a contaminant it advertises?
- A filter only earns credit for removing something if we can find that certification on the official NSF, WQA, or IAPMO database. When the registries return no listing, we say we found no accredited certification - which is not the same as saying the filter fails; it means the claim has not been independently verified.