This page is written by Echo Water about Echo's own products, so read it with that in mind. The review figures come from the reviews customers have left on echowater.com, collected by our review platform, Okendo, and counted on September 24, 2026. The lab results come from independent labs, in tests commissioned by Echo or arranged through its testing lab. The science links go to Hydrogen Studies, a research database that Echo Technologies also funds. It reports null results alongside positive ones.
Short answer: the Echo Flask has 537 customer reviews on echowater.com, with an average of 4.6 out of 5. Of those, 408 are five-star, and 93% of reviewers say they'd recommend it. Okendo marks 354 of the 537 reviews as incentivized, meaning the reviewer was offered a reward for writing one; those average 4.7 stars, and the other 183 average 4.4. Separately, the independent lab H2 Analytics measured 6.07 mg/L of dissolved hydrogen after a 10-minute cycle and 8.25 mg/L after a 20-minute cycle. Reviews tell you what owning the Flask is like, and the lab report tells you what's in the water. Neither tells you what hydrogen water does for your health.
Echo Flask reviews at a glance
| Measure | Echo Flask (echowater.com reviews, September 24, 2026) |
|---|---|
| Total reviews | 537, posted between February 2025 and September 2026 |
| Average rating | 4.6 out of 5 |
| 5 stars | 408 (76%) |
| 4 stars | 93 (17%) |
| 3 stars | 14 (3%) |
| 2 stars | 8 (1%) |
| 1 star | 14 (3%) |
| Would recommend | 93% |
| Incentivized reviews | 354, averaging 4.7 stars. The 183 reviews without an incentive average 4.4 stars. |
We show the incentivized split because it matters: reviews written in return for a reward rated the Flask higher on average than reviews written without one. If you want the most conservative figure, use 4.4.
What Flask owners praise and complain about
We read the reviews and grouped the practical, non-health themes. Many reviews also describe how people feel after drinking hydrogen water. We don't repeat those here: individual experiences can't show what hydrogen water does, and some reviewers mention medical conditions. For what the research does and doesn't show, see is hydrogen water real or fake?
In the four- and five-star reviews, the most common practical themes are:
- The design, touchscreen and lights
- How easy it is to set up and use
- Build quality
- The Echo Water app
- The taste of the water
- Being small enough to carry around
Of the 36 reviews with three stars or fewer, the most common complaints are:
- Battery life (13 reviews). Echo rates a full charge at about 60 minutes of generating time, roughly 5–7 ten-minute cycles, and that's fewer than some owners expected.
- Leaks or drips (7), from the lid or the port on the base. Echo says small drips from the oxygen port on the bottom are normal. Steady leaking, or a lid that won't hold pressure, is a support or warranty issue.
- App and Bluetooth pairing (7).
- Value for the price (7).
A few low ratings are about shipping, such as damaged or incomplete packages, rather than the Flask itself. The 12 oz size also comes up on both sides: some reviewers like that it's easy to carry, and others wish it held more.
Reviews of Echo's other hydrogen products
Echo's plumbed machines have far fewer reviews on echowater.com, too few to draw firm conclusions from:
- Echo Ultimate: 4.5 stars from 8 reviews
- Echo Flow: 4.5 stars from 8 reviews
- Echo H2: 4.3 stars from 6 reviews
To compare the machines on specifications and lab results instead, see our guide to the best hydrogen water machine for home.
Lab tests: what's been measured
Dissolved hydrogen in the Echo Flask
H2 Analytics tested the Flask in January 2025 (report H2AR-250116-1, dated January 16, 2025). It filled the Flask with about 350 mL of distilled water at 24.5 °C, ran each cycle three times, released the pressure, opened the cap and immediately sampled the water for gas chromatography (static headspace analysis).
- 10-minute cycle: a mean of 6.07 mg/L, or about 2.2 mg of hydrogen in the full bottle
- 20-minute cycle: a mean of 8.25 mg/L, or about 2.9 mg in the full bottle
Read the full report (PDF). These are favorable conditions, with distilled water measured the moment the cap came off, and the level falls once the bottle is open. For what those numbers mean, see hydrogen water ppm levels.
Metals in water from the Flask
A separate report from SGS Silver State Analytical Laboratories (work order 25030654, reported March 25, 2025, arranged through H2 Analytics) analyzed one water sample from an Echo Flask for more than 30 metals and other substances. Every metal on the list, including lead, nickel, chromium, platinum and titanium, was below the lab's reporting limit. The report doesn't state what water was used or how long the cycle ran, so treat it as a check on that one sample. Echo posts it, along with the hydrogen report, in the attachments to its Flask specifications guide.
Echo's machines
H2 Analytics also tested three of Echo's plumbed machines in June 2024, using ultrapure water sampled from a freshly filled beaker: the Echo Ultimate measured 1.46 mg/L, the Echo H2 1.43 mg/L and the Echo Flow 1.21 mg/L. The reports are on Echo's support site.
How to check the numbers yourself
You don't have to take anyone's lab report on trust, including ours:
- Use hydrogen reagent drops made for dissolved hydrogen, or a dedicated dissolved-hydrogen meter.
- Don't use an ORP meter or pH strips. They can't measure hydrogen.
- Test right after releasing the pressure, then again after the time you'd normally take to drink it.
- Use the water you usually drink, and average a few readings.
For a full walk-through, see how the Echo Flask works.
Returns: test it for 60 days
Echo accepts returns within 60 days of delivery for purchases made on echowater.com (see the return policy for the details and exclusions). That's long enough to run the tests above with your own water and decide whether the Flask fits your routine.
Where to read Echo reviews
- All Echo Flask reviews, on the Flask product page. You can sort them by rating to read the critical ones first.
- Reviews for each machine are on its product page, linked above.
- For the buying criteria we'd use for any brand, see our hydrogen water bottle buyer's guide.
Frequently asked questions
What is the Echo Flask's review rating?
As of September 24, 2026, 4.6 out of 5 from 537 reviews on echowater.com, with 408 five-star reviews. Okendo marks 354 of the reviews as incentivized; they average 4.7 stars, and the remaining 183 average 4.4.
What's the most common complaint about the Echo Flask?
Battery life. It's the most frequent theme in reviews of three stars or fewer, followed by leaks or drips, app pairing and value for money.
Has the Echo Flask been independently tested?
Yes. H2 Analytics measured 6.07 mg/L of dissolved hydrogen after a 10-minute cycle and 8.25 mg/L after 20 minutes, using distilled water and gas chromatography. A separate SGS Silver State report found every metal it tested in one water sample from the Flask below its reporting limits. Echo commissioned the H2 Analytics test, and the SGS test was arranged through H2 Analytics.
Do good reviews mean hydrogen water works?
No. Reviews describe people's experiences with a product, and they can't separate the effect of hydrogen from expectation or simply drinking more water. Human trials of hydrogen water are mostly small and short, with mixed results. See is hydrogen water real or fake? and hydrogen water side effects.
The evidence behind this page
- H2 Analytics report H2AR-250116-1 (Echo Flask)
- What is hydrogen water?
- Hydrogen water ppm levels
- Is hydrogen water real or fake?
- Hydrogen water side effects
Written by Echo Water. Last reviewed September 24, 2026. This is general information, not medical advice.