Best RO Systems 2026: Lab Analysis & Hands-On Testing

Reverse Osmosis Systems

• AquaTru Classic
• Waterdrop G3P600
• AquaTru Carafe
• Home Master TMHP-L HydroPerfection Loaded
• APEC ROES-50 Essence
• Bluevua RO100ROPOT
• Bluevua RO100ROPOT-Lite
• Brondell H2O+ Circle
• GE GXRQ18NBN
• Frizzlife PD600-TAM3
• Crystal Quest Countertop Thunder
• SimPure Y7P-BW
• Waterdrop A1 (Updated Version)

Please note: This page is still a work in progress. Additional content and details will be added shortly – stay tuned!

Paraphrased Video Script

Over the past one-and-a-half years, we’ve done some deep dives into reverse osmosis systems. We started by comparing 10 of the most popular countertop ROs, then moved on to 11 under sink models. Since then, we’ve added 4 brand-new reviews and even re-tested 2 updated units. But one thing we’ve never done is compare all of the systems side by side – until now. In this video, we’re putting 25 reverse osmosis systems head-to-head — countertop and under sink — and sharing our top picks!

Hey, Sara here from BOS Water, and our biggest RO system comparison yet. Because today, we are discussing our results from testing 25 of the most popular reverse osmosis systems (countertop and under sink), all with lab testing for real-world contaminant reduction and potential chemical leaching!

Going through all 25 in detail would take forever, so here’s the plan: we’ll start by comparing our top 3 picks — one countertop, one tank-based under sink, and one tankless under sink — and crown our ultimate #1. After that, I’ll quickly cover a few other systems that are worth a look depending on your needs.

If you want the full breakdown including lab reports, you can find it in our massive comparison sheet linked in the description. With 25 systems, it’s a lot of data. The sheet has all our product links and discount codes, so you can save some money and support the channel at the same time.

All 25 Systems Tested

Let’s start with a quick intro to all 25 systems, beginning with the newly tested countertop models:

First up, the Sans Water Purifier and the Bluevua Lite — both of these were highly requested.

We also re-tested the updated Waterdrop A1 and Waterdrop C1H since both have changed since our first countertop RO comparison.

And then we’ve got all the other countertop ROs from our earlier roundup:

• NU Aqua 4-Stage
• APEC ROCT-PLUS
• AquaTru Classic
• AquaTru Carafe
• Frizzlife WB99-C
• Crystal Quest Countertop Thunder
• SimPure Y7P

As for under sink systems, we added two new ones: the Waterdrop G3P800 and the iSpring RCC7AK — also highly requested.

From our previous under sink comparison we have:

• Aquasana SmartFlow
• US Water Systems All American
• Home Master TMHP-L
• APEC ROES-50 Essence
• Cloud RO
• Waterdrop G3P600
• Waterdrop X12
• SimPure T1-400 ALK
• Brondell H2O+ Circle
• GE GXRQ18NBN
• Frizzlife PD600-TAM3

There were different reasons why we picked these 25 RO systems. Some are backed by NSF certifications. Some include remineralization. Many are super popular on Amazon or were requested in the comments. A few even provide hot water — and one can dispense cold water, too. Among the under sink models, some are tank-based while others are tankless. Two are made in the USA. We wanted to cover the full price range — from budget-friendly to premium.

We’ll explain more about our testing as we get into the recommendations. Please subscribe to the channel and give this video a like if you want to see more content like this.

Top 3 Picks

Going into the race in the countertop category is the AquaTru Classic which is still our top pick here. For tank-based under sink, it’s the Cloud. For tankless under sink, the Waterdrop G3P600 takes the spot.

When rating every water filter we test, we look at three categories:

1. Filtration – combining our own lab testing, certifications & testing against NSF and other standards, plus taste and odor of the filtered water.
2. Usability – our experience with installation, day-to-day use, and filter replacements.
3. Cost – overall value for money.

Filtration carries the most weight at 60%, while usability and cost are 20% each. Scores may be adjusted slightly based on extra factors, like customer feedback.

Filtration and Lab Testing

Here’s what we did: we installed and primed the AquaTru Classic, the Cloud, and the Waterdrop G3P600 one by one, following each manual. For every system, we took two water samples — one unfiltered tap water, and one filtered. Then we had all samples analyzed in an independent lab. This is a before-and-after comparison of our tap water, looking at impurity and contaminant levels.

This isn’t an exact science. Results can be affected by small errors, cross-contamination, natural variations in the water, and more. We can only test for the contaminants present in our water supply. Think of this as a snapshot — not a final verdict.

Here’s how our three systems performed against each other:

• For chlorine and disinfection byproducts, all three achieved a 100% reduction.
• Same for copper, barium, and uranium.
• For boron, the AquaTru Classic came out on top with 100% reduction, while the Cloud and Waterdrop G3P600 removed 33%.
• For strontium, the Cloud led with 100% reduction, while the Classic and G3P600 achieved 96% and 94%.
• Nitrate: the Classic removed 100%. For the Cloud and G3P600, we could only calculate minimum reduction rates. Tiny traces were left, but too low to reliably measure.
• Same for fluoride. On paper, the Classic lagged with only 41% minimum reduction. But it is NSF-certified for fluoride reduction, with an official 93.5% reduction rate.
• TDS reduction came in around 90% with the Cloud ranking a little lower, but that’s only because it adds healthy minerals back into the water.
• In some cases, we couldn’t detect the contaminant in the unfiltered sample, so no reduction rate was calculated. In other cases, certain elements actually increased in the filtered water due to remineralization (zinc and manganese in the Cloud).
• The Classic showed 0.05 ppm aluminum. That might suggest a tiny amount of leaching, but it’s far below any health concern.

In summary, all 3 RO systems performed really well in our lab testing with the AquaTru Classic coming out slightly ahead with a score of 4.97 out of 5. The Cloud and the Waterdrop G3P600 were close behind, scoring 4.84 and 4.87 out of 5.

NSF Certifications

Aside from our own lab testing, we also like to rely heavily on NSF certifications. In case you’re not familiar: These certifications show that a filter has been independently tested against strict NSF standards. Some cover material safety and structural integrity, but the most important in our view are the ones for contaminant reduction, especially because the testing required to achieve certification is way more sophisticated than what we can do. For one, most standards require filters to be tested for their entire lifespan, not just the beginning.

Three organizations are accredited to certify against NSF standards:

• NSF itself
• WQA
• IAPMO

All three are equally valid. What matters is the specific standard being tested — for example, NSF 53 for lead reduction. Another advantage is that the certifiers are independent from the companies making the filters.

The AquaTru Classic holds all the key certifications which is a big reason it’s our top countertop RO pick. It’s certified against:

• NSF Standard 42
• NSF Standard 53
• NSF Standard 58
• NSF Standard 401

These cover more than 80 different substances. The official performance data sheet shows consistently high reduction rates for:

• Chlorine
• Chloramine
• PFOA and PFOS
• Microplastics
• Arsenic 5
• Chromium 6
• Fluoride
• Lead
• Nitrate
• A range of pharmaceuticals and other emerging chemicals
• Many VOCs

The Cloud has just one official certification so far:

• NSF 58 for TDS reduction (98%)

For comparison:

• AquaTru Classic lists 87.1%
• Waterdrop G3P600 about 94%

The Waterdrop G3P600 is certified for:

• Chlorine
• PFOA and PFOS
• Fluoride
• Cadmium
• Chromium 6
• Selenium

Both the Cloud and G3P600 also provide extra third-party test data against additional contaminants, but since those tests weren’t done by NSF, WQA, or IAPMO as part of a certification process, they didn’t result in official certifications. The data is still useful, but we take it with a grain of salt.

We always give preference to official NSF certifications, which is why for us the AquaTru Classic comes out on top. That doesn’t mean the Cloud or G3P600 are less effective — remember, the Cloud has the highest TDS reduction rate — but certifications add an extra layer of certainty.

As for filtered water aesthetics, all three systems performed equally well with no taste or odor remaining in their waters.

For overall filtration:

• AquaTru Classic earns a full 5 out of 5
• Cloud scores 4.5 out of 5
• Waterdrop G3P600 scores 4.5 out of 5

Usability

Countertop models like the AquaTru Classic are simple and non-permanent, which makes them ideal if you’re renting or not handy with tools. Under sink systems require more setup. You’ll need a hole in your countertop for the faucet, and another connection to your sink’s drain line. The upside is they stay out of sight, and you don’t have to manually fill or empty tanks — you just open the faucet and go.

For all three of these systems, installation and priming was as easy as it gets.

AquaTru Classic setup:

1. Install the three filter cartridges
2. Clean the front and back tanks
3. Fill the back tank with tap water and let the unit run
4. Empty and rinse both tanks after the first cycle
5. Repeat this three times before use

Cloud and Waterdrop G3P600 setup:

1. Shut off cold water supply
2. Install the feed water adapter
3. Cut a hole in your countertop or sink to insert the faucet and secure from underneath
4. Drill a hole in the drain pipe and install the drain saddle
5. Connect all components with the provided tubing
6. For the Waterdrop: connect faucet power cord, power adapter, and install filter cartridges
7. Turn on the water supply
8. Waterdrop: system flushes for 5 minutes, then run faucet for 30 minutes to prime filters
9. Cloud: fill and purge three full tanks

Both Cloud and G3P600 felt very high-quality. With the Cloud, we especially liked the packaging and labeled tubing making it one of the most thoughtfully designed under sink setups we’ve tested.

AquaTru Classic use:

1. Fill the one-gallon feed tank and place it on the base
2. Filtration starts automatically and takes 10–15 minutes
3. The process shuts off on its own
4. From a full cycle, over 0.6 gallons of clean water is stored in the front tank
5. Dispense with the blue button
6. The clean tank is removable and fridge-friendly
7. After emptying, dump wastewater from the feed tank, refill, and start again

Some people dislike the AquaTru design. It works well but isn’t the most attractive.

The AquaTru Classic Smart adds:

• TDS monitor
• App to track filter status and water consumption
• Feed and filtered TDS tracking

Cloud app features:

• Tracks running averages of feed, filtered, and remineralized water TDS
• Logs water consumption and tank level
• Provides data that sets it apart from most under sink ROs
• pH and mineral tabs are just estimates since the Cloud can’t actually measure those values

Cloud use:

• Dispense water from a solid RO faucet available in four finishes
• Filled an 8-ounce cup in about 6 seconds in our test
• Drew 2.2 gallons from a full tank before flow slowed
• Refilled in just over 23 minutes, the fastest in our comparison

Waterdrop G3P600 use:

• Tankless design filters on demand with a booster pump
• Provides continuous RO water
• Less dependent on home water pressure
• Saves space under the sink
• Downside: pump noise, though manageable in our testing
• Filled an 8-ounce cup in about 7 seconds
• TDS displays on both faucet and system module were accurate

Filter replacements:

• AquaTru Classic: filter change indicator on front panel, twist-out cartridges, reset button, flush two tanks after replacement
• Cloud: modular filters, no need to shut off water supply, twist replacements, app tracks usage and water quality
• Waterdrop G3P600: modular filters with filter life indicator, supported by TDS display

All three systems are easy to set up, use, and maintain, earning each of them a full 5 out of 5 for usability.

Wastewater

Every RO system produces reject water during filtration. Traditional tank-based units can waste three to five gallons for every gallon of purified water. The AquaTru Classic, the Cloud, and the Waterdrop G3P600 all do much better.

• AquaTru Classic: about 0.6 gallons wasted per gallon purified — not the best among the 12 countertop models tested, but still solid
• Cloud: best ratio of all tank-based systems at about 0.56 gallons wasted per gallon purified with the tank shut off; roughly 1:1 with the tank on, thanks to a permeate pump and electronic shutoff
• Waterdrop G3P600: about 0.75 gallons wasted per gallon purified; system auto-flushes five minutes after use to protect the membrane and reduce TDS creep, which adds about 4.5 cups of wastewater each cycle

If you dispense just a single cup with the G3P600, the ratio jumps to around 1:5.25. Drawing larger amounts is more efficient:

• 1 gallon dispensed creates about 1.02 gallons of waste — same as the Cloud
• Half a gallon dispensed gives a 1:1.3 ratio
• Small frequent draws lead to less efficiency

Summary of wastewater ratios:

• AquaTru Classic: 1:0.6 (lowest)
• Cloud: 1:1 (excellent for a tank-based model)
• Waterdrop G3P600: varies depending on usage, efficient in larger batches

Extra Notes

• AquaTru Classic: some users reported leaks or malfunctions. Our unit didn’t work at first because water had gotten into the front handle, but letting it dry fixed the issue.
• Cloud and G3P600: both have clean designs. The Cloud runs on a long-life battery instead of a power cord. The battery lasts 2 years, a new one is included with each filter set, and a return label is provided for recycling.
• Cloud uses remineralization to restore minerals and balance alkalinity. Lab testing showed low mineral addition because of short contact time, but in everyday use levels are likely higher, especially after downtime. Results vary with design and usage. Replacement cartridges are reasonably priced.
• AquaTru Classic also has an optional remineralization filter which we haven’t tested yet.

Costs

• AquaTru Classic: $375 with special link ($100 off). Slightly above average compared to other countertop models. 1-year limited warranty. Annual filter replacement about $135, below average for the 12 countertop ROs.
• Cloud: $549 with $50 discount code. Higher end for tank-based systems, but extra features, 1-year warranty, and 1-year satisfaction guarantee make it fair. Filters last about 12 months, annual cost around $200 — average for under sink ROs.
• Waterdrop G3P600: lists at $539, usually on sale. With extra 5% code, $402 at the time of filming — below average for tankless under sink ROs. 1-year limited warranty. Filter replacements about $145 per year, also below average, with an extra 5% off via subscription.

Value for money scores:

• AquaTru Classic: 3.95 out of 5
• Cloud: 4.72 out of 5
• Waterdrop G3P600: 4.68 out of 5

Overall Rankings

• AquaTru Classic: #1 RO among the 25 systems tested, with an overall score of 4.79 out of 5
• Cloud: 4.64 out of 5
• Waterdrop G3P600: 4.64 out of 5

If you prefer an under sink setup, both the Cloud and G3P600 are excellent options. The G3P600 shines with its tankless, on-demand filtration. The Cloud stands out as a tank-based model with an app, remineralization, low wastewater, and more. All three perform fantastically when it comes to purifying water.

Other Notable Systems

AquaTru Carafe:

• Only other countertop system tested that’s fully backed by NSF certifications
• Preferred by some over the Classic because of its smaller footprint and glass carafe instead of plastic
• Carafe fits easily in the fridge
• Strong usability with filter life indicator and low wastewater ratio
• Filtration results solid in lab testing though not as strong as the Classic
• Water tasted and smelled perfectly clean
• Our link takes $100 off, making it budget-friendly, though long-term filter costs are higher than the Classic

Bluevua Light:

• One of the few countertop systems with an attractive design
• Small glass carafe makes it best for singles and couples
• Good usability with touch screen, TDS monitoring, and filter life indicator
• Low pure-to-drain ratio
• Optional remineralization
• Filtration strong overall, but trace amounts of methylene chloride detected in filtered water, suggesting potential leaching
• Pricing is average with discount code
• No NSF certifications yet and only limited testing

Waterdrop A1:

• Larger countertop system providing hot, cold, and room temperature RO water
• Tested hottest water at 195 °F and coldest at 44 °F
• Excellent filtration with the highest TDS reduction rate seen so far
• Strong usability with large touch screen, presets, TDS monitoring, and temperature indicators
• Low wastewater
• Downsides: heavy, takes counter space, noise when cooling is on (can be disabled)
• More expensive upfront, long-term costs slightly below average
• Extra 3% off with code

Tankless Under Sink Systems

Waterdrop G3P800 and X12:

• Tankless, similar to the G3P600, with equally strong filtration and flawless water aesthetics
• Differences are in speed and features
• X12 is fastest tankless system tested: fills 8 ounces in 4.25 seconds
• G3P800 fills in 5.25 seconds, G3P600 in 7 seconds
• Both waste less water while retaining auto-flush
• Both include UV disinfection
• X12 adds remineralization stage and sleek one-touch faucet
• G3P800 has the most NSF certifications (10 substances, with supporting data)
• X12 has the least certifications
• Trade-off is price: X12 cost $974 with code at filming
• Long-term filter costs are more affordable
• Best for speed and features if you’re okay with premium price tag

Aquasana SmartFlow

• Tank-based system
• Delivered the best results in lab testing
• Holds all key NSF certifications
• Earned full marks for filtration
• Budget-priced with discount code
• Includes remineralization
• Relatively low wastewater ratio
• Provided plenty of water at a fast flow rate
• 90-day satisfaction guarantee and 2-year warranty
• Downsides: most expensive system to maintain (~$380 per year), build quality lower, tank valve could be improved, faucet leaked during test, no filter life indicator, mixed Amazon reviews

Made in USA Options

US Water Systems All American RO and Home Master TMHP-L:

• Both performed really well in lab and taste & odor tests
• Provide plenty of water at a fast flow rate
• Home Master was fastest of all under sink systems tested, filling 8 ounces in 3 seconds
• Home Master remineralizes water twice (before and after storage), includes KDF-85 for iron or sulfur in well water
• Solid build but no filter life indicator, no NSF certifications or contaminant test data at time of testing
• Setup a bit tricky, but filter changes simple once installed
• All American easier to install and service, uses traditional filter sumps, high build quality with double O-rings on pre-filters
• No filter life indicator but comes with TDS meter
• Lacks NSF certifications or test data
• All American had higher wastewater ratio, Home Master very low due to permeate pump
• Both more expensive upfront, but filter costs about average
• Backed by long 5-year warranties
• 5% discount code available for the All American

APEC ROES-50 Essence

• Most affordable under sink system in the comparison
• Costs around $200 upfront
• Yearly filter replacements $50 to $100
• Performed really well in lab testing
• Produced plenty of perfectly clean water
• Fast faucet flow
• Solid overall quality
• Easy setup, though we encountered a leaking feed valve missing a gasket
• Filter changes straightforward but use traditional sumps
• No filter life indicator
• Wastewater ratio standard for this type of system, higher than Cloud
• NSF certifications limited — just one for TDS reduction, no additional contaminant data available

Final Notes

You can check our full analysis of all 25 RO systems — including lab reports — in the comparison sheet linked below. The sheet also has our product links and discount codes if you’re looking to make a purchase.

If you found this video helpful, please subscribe and give it a like. Drop your questions in the comments, share your own experience with any of these systems, or let us know which filters you’d like us to review next.

Thanks so much for watching — see you in the next one!