Best reverse osmosis systems
Reverse osmosis (NSF/ANSI 58) is the most thorough point-of-use filtration and the only common type that removes fluoride, arsenic, nitrate, and dissolved solids. The trade-off is some water waste and a slower flow.
93 certified reverse osmosis models in our database · ranked by independent certification and cost per gallon · no paid placement.
GE GNRQ18NBN
Certified to reduce 18 contaminants, including lead. About 24.6¢ per gallon.
Prices shown are as of August 20, 2026 and may change — check Amazon for the current price. As an Amazon Associate we earn from qualifying purchases; some links are affiliate links and we may earn a commission at no extra cost to you. Disclosure.
How the top reverse osmosis filters compare
| Filter | Certified for | Contaminants | Price | ¢/gal | |
|---|---|---|---|---|---|
| GE GNRQ18NBN | Arsenic, Asbestos, Barium +15 | 18 | $63.87 | 24.6 | Buy |
| GE GXRQ18NBN | Arsenic, Asbestos, Barium +15 | 18 | $65 | 24.6 | Buy |
| GE GXRV40TBN | Arsenic, Asbestos, Barium +15 | 18 | $63.87 | 24.6 | Buy |
| Pentair GRO-575B | Arsenic, Atrazine, Barium +13 | 16 | $809 | 13.8 | Buy |
| Pentair OmniFilter RO2050 | Arsenic, Barium, Cadmium +11 | 14 | $21.69 | — | Buy |
| Pentair RO-2550 | Arsenic, Barium, Cadmium +9 | 12 | $17.22 | — | Buy |
| iSpring RCC7-BLK | Asbestos, Barium, Cadmium +6 | 9 | $239.99 | — | Buy |
| iSpring RCC7-BN | Asbestos, Barium, Cadmium +6 | 9 | $219.96 | — | Buy |
| iSpring RCC7AK-BLK | Asbestos, Barium, Cadmium +6 | 9 | $234.99 | — | Buy |
| iSpring RCC7AK-BN | Asbestos, Barium, Cadmium +6 | 9 | $234.99 | — | Buy |
| iSpring RCC7AK-UVBLK | Asbestos, Barium, Cadmium +6 | 9 | $354.99 | — | Buy |
| iSpring RCC7AK-UVBN | Asbestos, Barium, Cadmium +6 | 9 | $329.99 | — | Buy |
See all 102 reverse osmosis filters →
How to choose a reverse osmosis filter
Match it to your water. The best filter is the one certified for what's actually in your water. Look up your ZIP to see your contaminants, then confirm the filter's certified claim list covers them.
Certification tiers to know. NSF/ANSI 58 covers reverse osmosis performance (dissolved solids, and often arsenic, fluoride, nitrate). A filter is only credited for the exact claims it lists.
Installation & upkeep. Under-sink system with a dedicated faucet and storage tank. Expect to replace the element about 1×/year; the running cost of refills usually matters more than the sticker price.
Water waste. Traditional RO wastes 3–4 gallons per gallon produced; newer tankless units are far more efficient (EPA WaterSense caps at 2.3:1). Worth checking if you're on a well or metered.
Frequently asked
What's the most important thing when buying a reverse osmosis water filter?
Certification for the specific contaminant you care about. "NSF certified" is not one thing — a filter certified for lead (NSF 53) may do nothing for PFAS or fluoride, and NSF 42 only covers taste and chlorine. Check the exact certified claim, which we list for every filter.
Are these filters actually certified, or just "tested to" a standard?
Every filter here is listed in the public certification database of NSF, WQA, or IAPMO — meaning an independent body verified its claims. We never count "tested to" marketing claims that aren't backed by a listing.
How do you rank them — does anyone pay for placement?
No. We rank by independent certification coverage and true cost per gallon, computed before any buy link is attached. See our methodology.
Rankings use NSF/WQA/IAPMO public certification data and computed cost per gallon. We only attach a buy link when we can verify the retail listing is the certified model. Some links are affiliate links — see our disclosure.