Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.
Aquasana SmartFlow Reverse Osmosis comes out ahead by a narrow margin (4.6 vs 4.5). The gap is mostly about users with limited under-sink space who still want RO — read the strengths below before deciding.
The SmartFlow is the tankless RO pick — Aquasana's compact RO with smart leak detection saves space.
The MP99 is the budget pick — Frizzlife's easy-swap filter at under $100. Best for renters and first-time buyers.
Tankless RO. Smart leak detection. Premium price.
Cheapest. Twist-and-pull cartridge. Limited contaminant removal.
| Spec | Aquasana SmartFlow Reverse Osmosis | Frizzlife MP99 |
|---|---|---|
| Type | Tankless RO | Non-RO |
| Cert | NSF 58 | NSF 42/53 |
| Removal | 96% contaminants | 99% lead/chlorine |
| Feature | Smart leak detection | — |
| Cartridge | — | Twist-and-pull |