Alexapure vs ProOne: A Data Driven Comparison

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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.

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. 

📊 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. 

FactorAlexapure ProProOne Big+
Contaminant Reduction9.348.44
Filtration Rate8.007.50

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. 

FactorAlexapure ProProOne Big+Winner
Overall Score8.938.56Alexapure Pro
Health Related Contaminants9.708.65Alexapure Pro
Aesthetic Related Contaminants9.909.90Tie
Performance CertificationNot CertifiedNot CertifiedTie
Filtration Rate1 GPH0.77 GPHAlexapure Pro
Component QualityOutstandingOutstandingTie
Component CertificationnoneNSF 42 certificationProOne Big +
SetupExcellentGoodAlexapure Pro
Servicing RequirementsGoodGoodTie
Costs$0.59 per gallon$0.41/gallonProOne Big +

🚰 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. 

ContaminantMeasurementUnfiltered City WaterAlexapure Post-Filtration% ChangeProOne Post-Filtration% ChangeUnfiltered Pond WaterAlexapure Post-Filtration% ChangeProOne Post-Filtration% Change
Total THMsPPB35.20-100%18.69-47%NDNDNDNDND
E. coliCFU/100mlNDNDNDNDND150-100%0-100%
Total ColiformCFU/100mlNDNDNDNDND750-100%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: 

  1. A test on removing contaminants with health effects from our municipal water.
  2. 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. 


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+. 

ProductFiltration Rate ScoreFiltration Rate
Alexapure Pro8.001 GPH
ProOne Big+7.500.77 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. 

ProductPriceFilters Included
Alexapure Pro$2801 filter
ProOne Big+$229.951 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.  

ProductDesign ScoreComponent QualityMaterials Safety
Alexapure Pro8.40OutstandingNot certified
ProOne Big+10.00OutstandingNSF 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 Big+ and Traveler+ are stainless steel units, and the Big II has a BPA- and PVC-free plastic design.

proone gravity water filter system on countertop

Alexapure offers just one buying option for gravity-fed countertop water filters: 

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. 

Alexapure Pro on countertop

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.  

alexapure metal spigot

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. 

Brian installing the ceramic filter of ProOne+ Big

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.

ProductSetup ScoreSetup Time
Alexapure Pro9.0015-20 minutes
ProOne Big+8.5020-30 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. 

ProductMaintenance ScoreServicing RequirementsCosts
Alexapure Pro8.25Fair$0.59/gal
ProOne Big+8.75Good$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. 

ProductCompany ScoreWarranty LengthShippingReturns
Alexapure Pro8.651 yearFree shipping to the lower 48 states30 days
ProOne Big+8.905 yearsFree shipping to US-based customers30 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. 


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. 


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. 

We Recommend the Alexapure Pro if:

You have disinfection byproducts in your water and want a filter that has been proven in testing to effectively remove these contaminants. 
You don’t mind having just one option when it comes to system size and finish, and prefer the simplicity of there being just one filter size. 
You want the system that has the easiest setup, with absolutely no prep required for the filters.
Alexapure Pro unboxing

The ProOne Big+ is Best for:

Anyone looking for the most affordable option. The ProOne and Alexapure filters offer very similar results, so the lowest-cost ProOne Big+ offering is best for people who want to spend as little as possible.
Folks who prefer having the choice of a few different model types and sizes, including an option with a slightly larger water holding capacity (the Big+ holds 3 gallons)
People who want a system with certified components for materials safety.
proone unboxing
  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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