Top rated RO systems · ranked by score17 September 2026
The Waterdrop G3P600 ranks first of 69 reverse osmosis systems we have scored, at 7.6 out of 10. The ten on this list cost $190 to $999, and their scores are within 0.89 of each other. Across all 69, scores run from 4.3 to 7.6.
The top 10 at a glance
WaterdropG3P600
$539
WaterdropG3P800
$999
APEC Water SystemsROES-PH75
$269
APEC Water SystemsROES-50
$231
Express WaterRO5DX
$190
APEC Water SystemsRO-90
$265
APEC Water SystemsRO-PH90
$410
WaterdropK19-S
$309
AquasanaSmartFlow RO
$450
iSpringRCC7AK
$242
Every product we scored, placed by overall score. The 10 on this list are in color.
In order of overall score. Under each: where it wins and loses on the three criteria that separate these 10, and why it sits where it does.
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Just outside the ten: the APEC RO-Hi, 11th at 6.6, 0.06 behind.
Value, Certification Coverage and Contaminant Reduction.
| Overall | Product | Value3–9 | Certification Coverage5–10 | Contaminant Reduction7–10 | 3-criteria rank |
|---|---|---|---|---|---|
| 1 | WaterdropG3P600 |
5 | 7 | 8 | T-6 ▼5 |
| 2 | WaterdropG3P800 |
3 | 9 | 7 | 9 ▼7 |
| 3 | APEC Water SystemsROES-PH75 |
7 | 7 | 8 | T-4 ▼1 |
| 4 | APEC Water SystemsROES-50 |
9 | 7 | 8 | T-2 ▲2 |
| 5 | Express WaterRO5DX |
9 | 7 | 8 | T-2 ▲3 |
| 6 | APEC Water SystemsRO-90 |
7 | 7 | 8 | T-4 ▲2 |
| 7 | APEC Water SystemsRO-PH90 |
5 | 7 | 8 | T-6 ▲1 |
| 8 | WaterdropK19-S |
5 | 7 | 7 | 10 ▼2 |
| 9 | AquasanaSmartFlow RO |
5 | 10 | 10 | 1 ▲8 |
| 10 | iSpringRCC7AK |
7 | 5 | 8 | 8 ▲2 |
Ranked on these three alone, the order changes most for the Aquasana SmartFlow RO (9th overall, 1st on those three criteria) and the Waterdrop G3P800 (2nd overall, 9th on those three criteria).
3-criteria score: the weighted average of these three alone, and where it places each of the 10.
What holds across the list rather than for one product.
The same scores, cut by price. Rank is against all 69.
First edition - nothing to compare yet. From the next edition this section lists every move, with its cause:
On our scores, the Waterdrop G3P600: 7.6 overall, first of 69 we scored on 17 September 2026. The Waterdrop G3P800 is 0.03 behind at $999.
On our scores: the Waterdrop G3P600 (7.6), the Waterdrop G3P800 (7.5) and the APEC ROES-PH75 (7.3). We score 69 reverse osmosis systems in all, and the rest of the order is on this page.
On our scores, yes: 7.6 overall against 7.5. The Waterdrop G3P600 is ahead on value (5 against 3) and contaminant reduction (8 against 7). The Waterdrop G3P800 is ahead on certification coverage (9 against 7) and flow rate (9 against 7). They cost $539 and $999.
The Express Water RO5DX at $190, 5th of 69 overall. Next are the Aquasure Premier Advanced 75 GPD ($190, 26th) and the Express Water EZRO5 ($165, 32nd).
The 69 reverse osmosis systems we score list at $165 to $3,779 at the maker's own store, and half cost $367 or less. The ten on this list run $190 to $999.
The Aquasana SmartFlow RO scores 10 on certification coverage, the highest of the ten: it lists CSA B483.1, NSF/ANSI 42, NSF/ANSI 58, NSF/ANSI P473, NSF/ANSI 401 and NSF/ANSI 53.
Five carry a 2-year warranty: the APEC ROES-PH75, the APEC ROES-50, the APEC RO-90, the APEC RO-PH90 and the Aquasana SmartFlow RO.
The Aquasana SmartFlow RO scores 10 on contaminant reduction, the highest of the ten. It is 9th overall at $450.
The Waterdrop G3P800 scores 9 on flow rate, the highest of the ten. It is 2nd overall at $999.
Two score 9 on build quality, the highest of the ten: the Waterdrop G3P600 (1st overall) and the Waterdrop G3P800 (2nd overall).
The Waterdrop K19-S scores 10 on ease of installation, the highest of the ten. It is 8th overall at $309.
Two score 9 on value, the highest of the ten: the APEC ROES-50 (4th overall) and the Express Water RO5DX (5th overall).
The Express Water RO5DX at $190 (5th of 69 overall). The most expensive is the Waterdrop G3P800 at $999.
The Waterdrop G3P600, at 8.6 out of 10 on what owners and independent testers report, the highest of the ten. That comes from five sources, and it is 1st overall.
Of the ten on this list, APEC Water Systems has four, Waterdrop has three and Express Water, Aquasana and iSpring have one each. The top pick is from Waterdrop.
69, from 10 brands. We list 69 and rank every one.
By the overall score: half our specification score across eight criteria, half what owners and independent testers report across up to five sources. The same number sits on every product page.
This edition is dated 17 September 2026. The list is rebuilt whenever our product data changes, and a new edition goes up once it has been checked. Anything that moved since the last edition is listed on this page with the reason.
Head-to-heads between brands and products on this list.
Reverse OsmosisAPEC RO‑90 vs iSpring RCC77.0 vs 6.3
Reverse OsmosisAPEC RO‑90 vs iSpring RCC7‑BLK7.0 vs 6.6
Brand comparisonWaterdrop vs APEC Water SystemsEvery product both brands sell
Brand comparisoniSpring vs Express WaterEvery product both brands sellBrand comparisoniSpring vs WaterdropEvery product both brands sellBrand comparisonAPEC Water Systems vs iSpringEvery product both brands sellScores calculated 17 September 2026 · 69 products ranked; a product needs at least two independent sources to be ranked · How we score · All rankings
