Alexapure and ProOne manufacture two very similar stainless steel countertop gravity water filtration systems, and for this review, we wanted to see which – if any – is best.
In the matchup of Alexapure vs. ProOne, we’re comparing two different approaches to an almost identical filter system design. We personally tested both systems in our home to determine their ability to remove contaminants from our drinking water and river water, their speed of filtration, their setup and maintenance, and more.

Alexapure
Best For:

ProOne
Best For:
The Alexapure Pro has a 2.25-gallon water holding capacity. It did a great job of removing health-harmful contaminants from our city water and had the fastest water filtration rate. The ProOne Big+ holds 3 gallons of water. It struggled to remove disinfection byproducts from our water but offers more choice for model types/sizes, has a certification for materials safety, and is more affordable upfront.
Table of Contents
📊 Our Testing Data
In the table below, we’ve highlighted the 6 main criteria we used when testing and ranking the Alexapure Pro and ProOne Big+. You can see the scores for each system and how they compare.
Factor | Alexapure Pro | ProOne Big+ |
---|---|---|
Contaminant Reduction | 9.34 | 8.44 |
Filtration Rate | 8.00 | 7.50 |
Design | 8.40 | 10.00 |
Setup | 9.00 | 8.50 |
Maintenance | 8.25 | 8.75 |
Company | 8.65 | 8.90 |
Looking for a more detailed insight into the data behind each of our testing criteria? We’ve shared it in the table below. You can see the different sub-categories that we ranked the filters on to obtain our final scores.
Factor | Alexapure Pro | ProOne Big+ | Winner |
---|---|---|---|
Overall Score | 8.93 | 8.56 | Alexapure Pro |
Health Related Contaminants | 9.70 | 8.65 | Alexapure Pro |
Aesthetic Related Contaminants | 9.90 | 9.90 | Tie |
Performance Certification | Not Certified | Not Certified | Tie |
Filtration Rate | 1 GPH | 0.77 GPH | Alexapure Pro |
Component Quality | Outstanding | Outstanding | Tie |
Component Certification | none | NSF 42 certification | ProOne Big + |
Setup | Excellent | Good | Alexapure Pro |
Servicing Requirements | Good | Good | Tie |
Costs | $0.59 per gallon | $0.41/gallon | ProOne Big + |
Company | Good | Good | Tie |
🚰 Contaminant Reduction
We used two methods to give the Alexapure and ProOne filters an overall ranking for contaminant reduction:
- We conducted our own before-and-after testing to see what the filters removed from our water.
- We looked for official performance certifications for the filters.
Our Lab Test Results
The most important data we obtained was our lab testing results.
Both manufacturers claim that their filters can be used with potable water and non-potable water (like lake water, river water, etc.), so we did two separate tests for each filter – one with city water, and one with river water from our testing location in Colorado.
We’ve listed the contaminants detected in our source water, and how the Alexapure Pro and ProOne reduced these, in the comparison table below.
Contaminant | Measurement | Unfiltered City Water | Alexapure Post-Filtration | % Change | ProOne Post-Filtration | % Change | Unfiltered Pond Water | Alexapure Post-Filtration | % Change | ProOne Post-Filtration | % Change |
---|---|---|---|---|---|---|---|---|---|---|---|
Total THMs | PPB | 35.2 | 0 | -100% | 18.69 | -47% | ND | ND | ND | ND | ND |
Aluminum | PPM | 0.052 | 0 | -100% | 0 | -100% | ND | ND | ND | 0 | -100% |
Barium | PPM | 0.0127 | 0.0072 | -43.31% | 0.0275 | 117% | ND | ND | ND | ND | ND |
Calcium | PPM | 8.8 | 16.2 | 84.09% | 19.3 | 119% | ND | ND | ND | ND | ND |
Chloride | PPM | 6.9 | 6.8 | -1.45% | 8.3 | 20% | ND | ND | ND | ND | ND |
Chloroform | PPB | 35.2 | 0 | -100% | 15.5 | -56% | ND | ND | ND | ND | ND |
Copper | PPM | 0.0434 | 0 | -100% | 0 | -100% | ND | ND | ND | ND | ND |
Fluoride | PPM | 0.1 | 0.3 | 200% | 0 | -100% | ND | ND | ND | ND | ND |
Lead | PPM | 0.0006 | 0 | -100% | 0 | -100% | ND | ND | ND | ND | ND |
Magnesium | PPM | 2.19 | 3.97 | 81.28% | 7.91 | 261% | ND | ND | ND | ND | ND |
Manganese | PPM | 0.001 | 0 | -100% | 0 | -100% | 0.02 | 0 | -100% | 0 | -100% |
Potassium | PPM | 0 | 1.27 | n/a | 1.27 | n/a | ND | ND | ND | ND | ND |
Silver | PPM | 0 | 0.0247 | n/a | ND | ND | ND | ND | ND | ND | ND |
Sodium | PPM | 10.4 | 9.73 | -6.44% | 14.2 | 58% | ND | ND | ND | ND | ND |
Strontium | PPM | 0.062 | 0.087 | 40.32% | 0.098 | 37% | ND | ND | ND | ND | ND |
Sulfate | PPM | 10 | 8.4 | -16% | 16.9 | 69% | 42.29 | 27.1 | -36% | 27.4 | -35% |
E. coli | CFU/100ml | ND | ND | ND | ND | ND | 15 | 0 | -100% | 0 | -100% |
Enterococcus | CFU/100ml | ND | ND | ND | ND | ND | 4 | 0 | -100% | 0 | -100% |
Iron | PPM | ND | ND | ND | ND | ND | 0.1 | 0.02 | -80% | 0.02 | -80% |
Phosphorus | PPM | ND | ND | ND | ND | ND | 0.01 | 0 | -100% | 0.21 | 2000% |
Total Coliform | CFU/100ml | ND | ND | ND | ND | ND | 75 | 0 | -100% | 0 | -100% |
Both filters performed similarly in this testing category, but the Alexapure Pro got our highest overall rating because it performed better when removing health-related contaminants from our water.
Health-Related Contaminants
We conducted two separate tests to obtain one score for health-related contaminant reduction:
- A test on removing contaminants with health effects from our municipal water.
- A test of the Alexapure and ProOne filters’ ability to remove bacteria (our main concern) from river water.
Our City Water Test
The Alexapure Pro did a slightly better job at removing contaminants with health effects from our city water.
Our test results showed us that the Alexapure Pro had effectively removed 100% of the trace levels of the two disinfection byproducts (chloroform and total THMs), copper, aluminum, manganese, and lead that were present in our unfiltered water.
It also reduced 43% barium, 16% sulfate, 6% sodium, and 1% chloride.
The ProOne Big+ performed similarly, also completely removing aluminum, lead, copper, and manganese from our city water. It also removed 100% fluoride, which actually increased post-filtration in our Alexapure test (see below).
However, the Big+ only reduced THMs by 47%, and chloroform by 56%, so in this test, it didn’t perform as well as the Alexapure Pro at disinfection byproducts reduction, and that’s why its score was lower.
Were there any unexpected results?
Yes – in both the ProOne and Alexapure tests, some contaminants also increased post-filtration.
Fluoride, calcium, magnesium, and strontium increased in the Alexapure Pro’s filtered water, and potassium and silver appeared when they weren’t present before.
Barium, sulfate, strontium, and sodium increased in the ProOne Big+’s post-filtered water, and bromodichloromethane (another disinfection byproduct) appeared when it wasn’t present before.
After speaking to the chemists at the testing lab, we determined that the increase in most of the contaminants was likely because the water source we used for our testing was different than the water we used to prime the filters to the 100 gallons, which contained higher concentrations of these contaminants.
As for the bromodichloromethane that appeared in the water filtered by the ProOne Big+, we think this contaminant was actually present in our influent water but had dissipated before we were able to take our pre-filtration sample – hence why it only showed up in our filtered water.
Our River Water Test
In our untreated surface water test, both Alexapure and ProOne got top marks for their ability to remove bacteria from the water.
The ProOne Big+ and the Alexapure Pro both eliminated total coliform, E. Coli, and Enterococcus detected in our unfiltered water sample.
Aesthetic Contaminants
The Alexapure Pro and ProOne Big+ got the same high scores for aesthetic water quality.
Our unfiltered city water contained around 0.5 PPM of chlorine. This contaminant is mainly responsible for aesthetic issues in municipal water because it gives water a “swimming pool” taste and smell.
Both systems use activated carbon filter media, so we were unsurprised to see that they completely removed the chlorine from our water.
Certifications
We look for performance certifications as proof that a water filter can reliably remove the contaminants we’re concerned about in our drinking water.
Manufacturers don’t need to obtain performance certifications, and neither Alexapure nor ProOne have got their filters certified. (They both have third-party lab testing to NSF/ANSI Standards, but no official testing/certifications by the NSF, IAMPO, or the WQA).
That meant the Alexapure Pro and ProOne Big+ both obtained a lower score in this category. We’d love to see these manufacturers obtain an official certification to provide customers with that extra reassurance that their filters perform as advertised.
🚦Filtration Rate
As gravity filtration systems, the Alexapure Pro and ProOne Big+ filter water more slowly and steadily, and their filtration rate is measured in gallons per hour (GPH).
To obtain scores for filtration rate, we timed how long it took the Alexapure and ProOne systems to filter our water. We then compared these timings to the average filtration rates for gravity-fed systems.
In the below table, we’ve documented the filtration rates for the Alexapure Pro and ProOne Big+.
Product | Filtration Rate Score | Filtration Rate |
---|---|---|
Alexapure Pro | 8.00 | 1 GPH |
ProOne Big+ | 7.50 | 0.77 GPH |
The Alexapure Pro filtered water at a slightly faster rate of 1 GPH with just one filter, while the ProOne Big+ had a filtration rate of 0.77 GPH, using two 9-inch filters.
That made the Alexapure Pro the fastest option, especially given that you could add an extra filter to increase the filtration rate further. In comparison, we were already using two of the largest filters in the ProOne model.
💲 Upfront Cost
As we write this review, the cost of the Alexapure Pro, including a single filter, is around $280. You can buy a second filter for an extra $120.
The ProOne Big+ costs $229.95 with one 7-inch filter, and there’s the option to upgrade to multiple filters and increase the filter size (from 7 to 9 inches). The most expensive model, with three 9-inch filters, costs $379.95.
That makes the ProOne Big+ the best option if you want to spend the least amount of money upfront because its lowest-priced offering is around $50 cheaper than Alexapure’s cheapest option.
Product | Price | Filters Included |
---|---|---|
Alexapure Pro | $280 | 1 filter |
ProOne Big+ | $229.95 | 1 filters |
📐 Design
We awarded Alexapure and ProOne their design scores based on two factors:
- What we thought about their component quality (from our own experience using the systems)
- Whether or not the systems had an official certification for materials safety
The table below shares a breakdown of the individual scores we assigned to ProOne Big+ and Alexapure Pro, and how these affected their overall design scores.
Product | Design Score | Component Quality | Materials Safety |
---|---|---|---|
Alexapure Pro | 8.40 | Outstanding | Not certified |
ProOne Big+ | 10.00 | Outstanding | NSF 42 certification |
ProOne was the better brand in this category because it has been certified for component safety.
Filter Models
There are currently three models in the ProOne countertop gravity filter range:
- The ProOne Traveler+ (2.25 gallons)
- The ProOne Big+ (3 gallons)
- The ProOne Big II (2.5 gallons)
The ProOne Big+ and Traveler+ are stainless steel units, and the Big II has a BPA- and PVC-free plastic design.
Alexapure offers just one buying option for gravity-fed countertop water filters:
- The Alexapure Pro (2.25 gallons)
We think ProOne is the better brand if choice is what you’re looking for. You can choose between different model sizes and go for the plastic option if you want a lightweight water filter to take on your travels. Alexapure’s single offering gives you no choice in system size or materials.
ProOne also lets you choose between a brushed steel or polished steel finish for its stainless steel models, and you might prefer to have the choice between two different looks.
Component Quality
The Alexapure Pro and ProOne Big+ have almost identical designs. We gave them the same scores for component quality because they’re both made from high-quality stainless steel, with minimal plastic components.
We were pleased with the sturdy, rigid feel of both systems, and we didn’t notice any rusting of the chambers during our testing period. Note: we have seen mentions of rusting on select Amazon reviews, but we can’t confirm the legitimacy of these comments, especially given that Amazon reviews are so easy to manipulate.
We also appreciated that both systems came with a stainless steel spigot. Several of their well-known competitors provide a plastic spigot, with the option to upgrade (at an extra cost) to a stainless steel version. We prefer having a stainless steel spigot included in the price given that it prevents contact with plastic after our water has been filtered.
Are the Alexapure and ProOne systems entirely plastic-free? No – their filter cartridges still use plastic, but this is unfortunately almost impossible to avoid and, in our opinion, doesn’t affect the overall design quality.
Filter Materials
Both the Alexapure Pro and the ProOne Big+ use activated carbon filters with a ceramic outer layer.
Activated carbon and ceramic filters are typically made from natural materials, like charcoal, coconut shell, and clay, so they’re safe to use for water treatment.
Activated carbon is best known for its ability to remove chlorine, tastes, and odors from water, while ceramic filter media is a proven method to reduce microbiological contaminants. Our own test results for contaminant removal are proof that the filters were doing their job well.
Materials Safety Certification
As with performance certifications, manufacturers can obtain certifications for design and component safety, proving to their customers that their products are safe and reliable for water filtration.
We couldn’t find proof of materials safety certifications for the Alexapure Pro, which let it down in this category.
ProOne has obtained an NSF 42 certification for its filter elements. The certification is for material requirements only (so it doesn’t mean they’re NSF 42 performance-certified).
⚙️ Setup
We compared how long it took to assemble and prepare the filters for the ProOne and Alexapure units, and how difficult we found the process.
Here are the scores we awarded to the Alexapure Pro and the ProOne Big+ in this category.
Product | Setup Score | Setup Time |
---|---|---|
Alexapure Pro | 9.00 | 15-20 minutes |
ProOne Big+ | 8.50 | 20-30 minutes |
Alexapure just scraped a win in this category, although we found both systems pretty quick and easy to assemble out of the box.
Assembling the Alexapure Pro took less than 30 minutes and included connecting the components and installing the filters. Our filters had been pre-primed and were shipped to us in a sterile plastic bag, which is why the Alexapure Pro got the slightly higher score.
We also didn’t have to prime the filters for the ProOne Big+, but we did have to hold them under running cold water and use the included scotch brite pad to scrub them for a couple of minutes, which meant they required slightly more work than the Alexapure Pro. Still, this wasn’t difficult or time-consuming, and setup for the Big+ also took us less than 30 minutes.
🔧 Maintenance
We scored the Alexapure and ProOne systems in this category based on their separate scores for servicing requirements (and how easy we found maintenance) and maintenance costs (our calculated cost per gallon based on the manufacturer’s information on filter lifespan).
The table below breaks down the filters’ maintenance scores.
Product | Maintenance Score | Servicing Requirements | Costs |
---|---|---|---|
Alexapure Pro | 8.25 | Fair | $0.59/gal |
ProOne Big+ | 8.75 | Good | $0.41/gal |
Here, ProOne did slightly better because it had the slightly lower cost per gallon.
Servicing Requirements
Both the Alexapure Pro and the ProOne Big+ have simple maintenance requirements. Our main job was to replace the filters, and that was pretty easy for both manufacturers.
As with the initial filters we received, our replacement filters for the Alexapure Pro had been pre-primed, which meant we could install them and start using them straight away.
For the ProOne Big+, we also had the same situation as with the initial filters. The replacement filters didn’t require priming aside from a quick scrub under cold water, and they were easy to install.
We also had to clean the stainless steel water chambers (we did this at least once a week), which was easy and didn’t require any specialist cleaning products – just hot, soapy water. If your kitchen sink is quite small, you might find it tricky to fit the chambers underneath your faucet.
Maintenance Costs
As far as maintenance costs are concerned, we calculated that each 9-inch filter in the ProOne Big+ had a cost per gallon of $0.41/gallon. That’s pretty cheap, although not the lowest price we’ve seen for countertop gravity filters.
A single filter in the Alexapure Pro costs $0.59 per gallon, so slightly more expensive than ProOne’s biggest filters. Still, this is about the average price for a filter of this kind.
🏢 Company
Here, we compared the two companies, Alexapure and ProOne, including their warranty length, shipping, and returns.
Find our company scores and the individual data for each manufacturer in the table below.
Product | Company Score | Warranty Length | Shipping | Returns |
---|---|---|---|---|
Alexapure Pro | 8.65 | 1 year | Free shipping to the lower 48 states | 30 days |
ProOne Big+ | 8.90 | 5 years | Free shipping to US-based customers | 30 days |
ProOne got the highest score in this category, with a better score for warranty length (which had the most weight in the overall score).
Warranty Length
Alexapure only offers a 1-year warranty for its filters, while ProOne warrants its water filters for 5 years (excluding the filter media or elements). ProOne is the clear winner here – most countertop water filter manufacturers only warrant their products for 1 year.
Shipping
Alexapure offers free shipping to the lower 48 states, and this applies to all orders, regardless of spend.
ProOne offers free shipping to US-based customers who spend more than $69.95. Orders to Hawaii and Alaska incur a shipping fee, and orders to Canada may be “subject to duties and taxes”.
This makes Alexapure the winner in this category because there’s no order minimum.
Returns
Both Alexapure and ProOne allow customers to return their filters within 30 days of their purchase, so they’re equal in this category.
⛔️ System Setbacks & Flaws
There are a few specific setbacks and flaws of the Alexapure and ProOne systems that we think are worth mentioning here.
Alexapure Setbacks
- No official performance certification – Alexapure currently only has third-party testing data to support its contaminant removal claims.
- Only comes with 1 filter – The Alexapure Pro comes with just one filter, and buying an additional filter is pretty expensive.
- Only one size available – We had just one choice when it came to size, type, and finish for the Alexapure Pro.
- Overflow risk – We noted that continuing to fill the top chamber when the bottom chamber was full caused water to overflow from the seal between the two chambers.
- Didn’t reduce water’s fluoride concentration – Alexapure claims to remove up to 97% fluoride, but in our own testing, no fluoride was removed from our water. Since we believe this may have been a temporary issue, we plan to re-test the Alexapure Pro for removing fluoride.
ProOne Setbacks
- Not performance certified – Like Alexapure, ProOne doesn’t have any official performance certifications.
- Overflow risk – We identified the same overflow risk with the Big+ as with the Alexapure Pro.
- Didn’t eliminate disinfection byproducts – The ProOne Big+ did reduce our water’s disinfection byproducts, but the results were underwhelming.
🆚 Alexapure or ProOne: Which One’s for You?
Ultimately, both the Alexapure and ProOne water filters have advantages and disadvantages, depending on what you’re looking for.
I ‘m in the market for a counter top water filtration system. I’ve seen your testing of the Berkey vs Alexapure and the alexapure vs Big One. I live by myself, so 20 gallons is fine, on a large pond fed by a creek, where many cows drink, so after raining, cow poop may easily leech into the pond. I also have city water. I thought Berkeys were the best, but your testing, which I am impressed with, points to the Alexapure. Is there another I should look at? I respect your opinion, and thank you for the tests.
I assume you drink the city water, not the pond water? I’d highly recommend a countertop reverse osmosis system over a gravity-fed system, assuming you are drinking the treated city water.