Aquasana no longer sells the OptimH2O reverse osmosis system, but its filters are still available. WQA certifies the system for fluoride, lead, PFOA/PFOS, arsenic V and nitrate, so it’s worth keeping if you own one.
The catch: Its filters cost about $285 a year. If you’re buying new, the Aquasana SmartFlow replaces it.
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Is the OptimH2O discontinued?
Yes. Aquasana’s reverse osmosis range now lists only the SmartFlow, and the OptimH2O (model AQ-RO-3, sometimes sold as AQ-RO-3.55, .56 or .62 for the faucet finish) is gone from it. Aquasana and Amazon still sell all three of its replacement parts, so an existing system can keep running. WQA still lists it as certified.
We’ve stopped scoring it, because you can’t buy it new. This page covers what it’s certified for, which filters it takes and when to change them, and what to buy if you’re replacing it.
Replacement filters and when to change them
| Part | What it is | Change every | Price |
|---|---|---|---|
| AQ-RO3-R | Stage 1 and 3 Claryum carbon cartridges (pair) | 6 months or 365 gallons | $89.99 · Amazon |
| AQ-RO3-RO | Stage 2 reverse osmosis membrane | 12 months (Aquasana) | $62.99 at Aquasana |
| AQ-RO3-RM | Stage 4 remineralizer | 12 months | $41.99 · Amazon |
| AQ-RO3-RO + RM | Membrane and remineralizer together | 12 months | $104.98 · Amazon |
WQA certifies the AQ-RO3-R cartridges for 365 gallons. Aquasana gives the membrane’s life as 12 months on most pages and 2 years on one; 12 months is the safer plan. The SmartFlow’s filters don’t fit the OptimH2O, and the OptimH2O’s don’t fit the SmartFlow.
A year of filters comes to about $285: two AQ-RO3-R pairs ($179.98) plus the membrane and remineralizer ($104.98). Aquasana’s Water for Life plan takes 15% off replacements bought from Aquasana.
What it’s certified to remove
Every row below is on WQA’s listings for the OptimH2O AQ-RO-3, seen on 7 October 2026.
| Contaminant | OptimH2O | Certified to |
|---|---|---|
| Lead, mercury | Certified | NSF/ANSI 53 |
| PFOA and PFOS | Certified | NSF/ANSI 53 |
| Fluoride | Certified | NSF/ANSI 58 |
| Arsenic Vat 300 ppb influent | Certified | NSF/ANSI 58 |
| Nitrate / nitrite | Certified | NSF/ANSI 58 |
| Chromium-6, trivalent chromium, cadmium, copper, barium, selenium, radium | Certified | NSF/ANSI 58 |
| Total dissolved solids (TDS), turbidity | Certified | NSF/ANSI 58 |
| Cysts, asbestos, MTBE, VOCs | Certified | NSF/ANSI 53 |
WQA lists the system at 13.32 gallons a day under test conditions, with replacement elements AQ-RO3-RO and AQ-RO3-R. Aquasana’s performance data sheet also lists NSF/ANSI 42 (chlorine, chloramine) and NSF/ANSI 401 claims.
What replaced it: the SmartFlow
Aquasana’s SmartFlow (AQ-SFRO2) is the current model. WQA certifies it for the same headline contaminants, including lead, PFOA/PFOS, fluoride, arsenic V and nitrate, and it makes about twice as much water a day under test (25.7 vs 13.32 gallons). It also costs less to buy. Its carbon blocks are certified for 250 gallons, so its filters aren’t much cheaper to run.
Aquasana SmartFlow RO
APEC RO-90
AquaTru Carafe
Common questions
Can I still buy filters for the Aquasana OptimH2O?
Yes. Aquasana and Amazon sell the AQ-RO3-R cartridges, the AQ-RO3-RO membrane and the AQ-RO3-RM remineralizer.
Do SmartFlow filters fit the OptimH2O?
No. Aquasana’s filter listings say they aren’t compatible with the SmartFlow, and the SmartFlow uses different parts (AQ-SFRO-S1S3, AQ-SFRO-S2 and AQ-SFRO-REMIN).
How often should I change the OptimH2O filters?
The AQ-RO3-R cartridges every 6 months or 365 gallons, and the membrane and remineralizer every 12 months.
Is the OptimH2O still certified?
Yes. WQA still lists the AQ-RO-3 under NSF/ANSI 58 for fluoride, arsenic V, nitrate and metals, and under NSF/ANSI 53 for lead, mercury and PFOA/PFOS. Our NSF certification guide explains how to check a certifier’s listing yourself.
Should I replace my OptimH2O with a SmartFlow?
Not while it’s working and you can get filters. If it fails or you’re buying new, the SmartFlow is Aquasana’s replacement. Compare others in our reverse osmosis guide.
- Certifier listings: WQA, Aquasana Inc.: NSF/ANSI 58, OptimH2O AQ-RO-3, 13.32 gpd, elements AQ-RO3-RO and AQ-RO3-R, claims arsenic V (300 ppb), barium, cadmium, copper, fluoride, chromium-6, nitrate, nitrite, radium 226/228, selenium, TDS, trivalent chromium, turbidity. NSF/ANSI 53, AQ-RO-3, element AQ-RO3-R, 365 gal, 0.8 gpm: asbestos, cyst, lead, mercury, MTBE, PFOA, PFOS, turbidity, VOC.
- Also searched: NSF International (Aquasana): UV systems only.
- Maker documents: Aquasana AQ-RO-3 performance data sheet, Aquasana reverse osmosis category page (system no longer listed), replacement filter pages.
- Independent lab tests: None used.
Sources
Prices as of October 14, 2026. Product prices and availability are accurate as of the date/time indicated and are subject to change. As an Amazon Associate we earn from qualifying purchases.