The Short Version

The Long Version

Clean drinking water is a human right, not a privilege. While there are different means of ensuring you have pure, fresh H20, a reverse osmosis (RO) system is one of the most practical and effective.

The problem is, there’s not always the under-sink space to spare, especially if you’re living in an eco-house, dormitory or mobile home. Even with renting you are likely to face a similar struggle, due to not being able to make changes to the home’s plumbing system.

Thankfully, RO systems come in all shapes and sizes, with countertop models often the most suitable for tricky circumstances. Instead of pesky installations and unwanted complications, countertop RO systems are generally a breeze to set up and run. Not only will you enjoy superior portability, you won’t sacrifice on performance either.

Here’s our curation of the best countertop reverse osmosis systems for wetting your whistle. Rest assured we’ve pored over the research, so the only pouring left for you to do is a tall glass of delicious, filtered water!

If you love reading this review of the best countertop reverse osmosis systems, then you'll likely love reading some of our other water treatment content:

Best Overall: AquaTru

PURIFICATION: 4-stage

FLOW RATE: 96 gallons per day; 4 gallons per hour

DRAIN RATIO: 4:1

PRICE: $$$

PROS: NSF-certified to remove 83 contaminants; no installation; staggering 80% efficiency; built-in TDS meter; trackable water consumption 

CONS: Designed for cold water only; some reported leaking

As fancy as an RO system can be, it first and foremost needs to be able to purify water. You may have seen products with NSF (National Sanitation Foundation) labels, which they earn by being rigorously tested for sanitation. Well, the AquaTru has gone and landed NSF42, 53, 58 and 401 certifications, as well as P473.

What does this mean in English? Uncontested purification within the countertop market, if not the overall RO market. With help from their patented Ultra Reverse Osmosis™, say goodbye to lead, mercury, chlorine, chloramine, nitrates, fluoride, arsenic, cyanide, radium, cyst (giardia), VOC, PFOS, PFOA, TDS, and practically any other letter combination you can think of!

Principle function duly dealt with, the AquaTru also eliminates the hassle of installation, making it a brilliant choice for tighter areas. Users manually refill a one-gallon feed reservoir, so there’s no need to travel to the dusty under-sink world. The unit does require electricity (120V AC) to power the built-in pump and accompanying tech, but that’s it!

If you’re worried about waste water the AquaTru achieves 80% efficiency, so it produces 4 gallons of pure water with only 1 gallon waste. You will genuinely struggle to find a better drain ratio. Furthermore, you can keep track of your water consumption with their mobile app. As for flow rate, the integrated pump allows you to purify 4 gallons an hour, which is competitive amongst countertop options.

Last but not least, the pre and post-filters will last you approximately 600 gallons, between 6 and 12 months of typical household usage. The RO membrane, however, will get through 1,200 gallons, keeping operation costs low. When the indicator light shows, you can change filters in literally a few minutes.

Not the cheapest countertop RO system, but definitely the best we’ve seen!

Best for Subtlety: APEC RO-CTOP-C

PURIFICATION: 4-stage

FLOW RATE: 90 gallons per day; 3.75 gallons per hour

DRAIN RATIO: 1:1

PRICE: $$

PROS: Majority US made components; minimal installation; attractive aluminium casing; no electricity required; tool-free changing of NSF-certified filters

CONS: Incompatible with pull-out or sprayer faucets; faucet connections could be a bit more robust

The heart of any RO system is the filters, so it’s admirable that every single one found in the APEC RO-CTOP-C is manufactured in the US. Expect clever design – the 10" NSF-certified filters are rapidly replaced thanks to 1/4" quick-connect fittings – and premium quality. 

Aside from removing standard pests, like sodium, fluoride and chlorine, the APEC RO-CTOP-C is guaranteed to eliminate copper, mercury, magnesium, asbestos, VOCs, pharmaceuticals, and carcinogens (THMs). This RO system will also deal with foul odours and tastes, rather impressive considering that it doesn’t even require electricity.

Their science behind tasty, clean hydration comes in the form of both sediment and activated carbon (coconut shell) pre-filters, a FilmTech™ TFC membrane, and a carbon post-filter. The pre-filters are rated for 600-800 gallons, or 6-8 months of usage, whereas the RO membrane and post-filter will hold out for a remarkable 2-3 years. 

There’s no doubt the water ends up ultra-pure, though a 1:1 drain ratio isn’t the most impressive. Nevertheless, it’s still much less wasteful than older models. 

If the thought of installation brings on a headache, there’s no need to worry here. A diverter valve is installed directly onto the faucet, which is very straightforward providing you have standard sized fixtures. If you do rock custom faucets, this RO unit simply won’t do.

Finally, there’s something to be said for the sleek, sturdy brushed aluminium case, which will integrate far more nicely with your prized appliances when compared to white plastic alternatives. It’s low-impact and classy, perfect for minimalists or the super tidy.  

Assembled and tested in USA, this is exactly where hassle-free design meets luxury finish.

Best for Efficiency: Frizzlife WA99

PURIFICATION: 4-stage

FLOW RATE: 100 gallons per day; 4.17 gallons per hour

DRAIN RATIO: 5:1 

PRICE: $$$

PROS: Epic 5:1 drain ratio; built-in TDS in and out meters; filter condition indicators; no installation; attractive design; NSF58-certified

CONS: Gloss plastic front attracts fingerprints; smaller feed tank

With other RO systems, it’s often a case of form following function, which is to say they can end up looking a little unrefined. While that’s not a problem if you take the under-sink route, a countertop unit has to look good. Or, in the case of the Frizzlife WA99, it has to look absolutely stunning.  

Whereas white units look clean in the kitchen, an attractive gloss black finish with silver-grey highlights look fantastic anywhere in the home. Neutral tones are low-impact and complement the large, bright LED display, involving both in and out TDS meters as well as individual filter lifespan bars.

But enough about looks. The Frizzlife WA99 offers a whole heap more, most notably the unbelievable 5:1 drain ratio. Not only does the booster pump allow for this insane level of efficiency, it also gets to work eliminating a wide range of impurities, alongside four high-performance filters.

Firstly, a sediment filter catches large particles (sand silt, dirt), after which a carbon block (CB) filter eliminates common culprits like chlorine. Next comes the reverse osmosis, a 0.0001 micron membrane that can catch 99.99% of over 1,000 contaminants (e.g. lead, chlorine, fluoride, mercury, chloramine, arsenic). Lastly, a granular activated carbon (GAC) filter will tackle the remainder, ‘polishing’ the water for you to then enjoy.

The design team were obviously interested in user convenience. The unit is compact, thanks to the vertical stacking of filters. You can select cup size (5oz, 8.5oz, 11oz) or just stick to continuous flow. Quick-twist filters are removed in literal seconds, using the supplied wrench tool. You won’t even have to install it, aside from plugging it in (110V) of course. 

The Frizzlife is all about doing a good job and looking darn good while doing it.

Best for Output: Waterdrop G3

PURIFICATION: 3-stage

FLOW RATE: 400 gallons per day; 16.7 gallons per hour

DRAIN RATIO: 1:1

PRICE: $$$$

PROS: NSF58/372-certifed; included smart faucet; 94% TDS rejection; integrated safety features; designed for both countertop and under-sink

CONS: Must use included smart faucet; operating noise of 65dB

Perhaps the largest draw of the Waterdrop G3 is the tremendous flow rate, a whopping 400 gallons per day. Though we can’t say we enjoyed it, we have done the maths. With a flow rate of 0.28 gallons a minute, you fill a standard 8oz cup in 13-14 seconds. 

All of that delicious, fresh water is brought to you through the smart faucet, food grade copper-zinc alloy with brushed nickel plating. It will flash the appropriate LED lights to show filter status: blue for all good, yellow for last 40 gallons, and red for immediate replacement. Meanwhile, the TDS meter on the front panel lets you check water quality in real time. 

When filters must be replaced, users benefit from front panel twist-knobs that the most inexperienced will sail through. That’s pretty much the only job you’ll have, though, as the Waterdrop G3 has a whole host of integrated safety features. 

There’s obviously leak protection, but also automatic cut-off if you leave the faucet running and automatic flushing to extend the filter lifespan. Also, after 24 hours of no usage, the system is automatically flushed, so there’s no worry when going away for the weekend.

I suppose we should talk about the filter technology, which is equally as impressive as the rapid flow rate. This RO system makes use of both composite pre-filter (CF), tackling a range of physical and chemical impurities, and carbon block (CB) post-filter, for removing any residual contaminants. In the middle, the 0.0001μm membrane stops 1000+ pollutants, such as heavy metal, fluoride, arsenic and bacteria. 

Waterdrop delivers a heap of quality and quantity, perfect for the busier home or office.

Best for Economy: KFLOW ROPOT-180

PURIFICATION: 4-stage

FLOW RATE: 168 gallons per day; 7 gallons per hour

DRAIN RATIO: 1:1

PRICE: $$$$

PROS: Eliminates 99.9% of listed metals and organics; recycles waste water for better efficiency; 96.8% desalination; zero installation

CONS: 1.5 litre feed tank; recycling waste water is not automatic; some users report poor efficiency

Boasting no installation and a 3 second filter change time, the KFLOW ROPOT-180 certainly makes clean water convenient. You can put it literally anywhere within reach of a power outlet. The 4-stage purification works all the same, wherever you end up positioning it!

First, the polypropylene (PP) filter removes physical particles, before a CTO filter removes chlorine and various other organic material. As most 0.0001 micron RO membranes do, it stops over 1,000 contaminants, but a 99.9% heavy metal removal rate is especially pleasing. A carbon block (CB) filter, made from coconut shell, is the last stage, ensuring that even the most resilient impurities are taken out.  

This RO system comes in clean white with some nice embellishments, such as the LED monitor (showing filter condition and water quantities), gold branding and stylish pitcher. As versatile as plastic is, however, it can release chemicals or leak as it ages. Luckily here, food-grade NSF-certified materials ensure your water remains pure, which is the name of the game, after all. 

You can expect TDS as low as 20ppm. If you’re not already familiar with RO systems, that’s likely to be one of the purest sip you’ve ever taken. However, one of the most unique selling points is the recycling capabilities. 

The KFLOW ROPOT-180 will gladly reuse waste water, what they call ‘multi-filtration technology’. It’s certainly a plus compared with many competing countertop products. Although the manufacturers advise you circulate water no more than 4 times, a system designed to take in its own waste water saves you water and money.

If you’re looking for something equal parts innovative and dazzling, look no further!

Best for Alkalizing: AlcaPure Countertop

PURIFICATION: 4-stage

FLOW RATE: 50 gallons per day; 2.1 gallons per hour

DRAIN RATIO: 1:1

PRICE: $$$

PROS: Post-filter mineralization; no installation; BPA-free plastic; compatible with their zero-TDS post-filter; 12 month pre-filter lifespan

CONS: No indicators for individual filter status; 1 gallon tank best suited for smaller households

It may seem strange, but you can end up with water that’s too pure. Obviously, we aren’t saying you leave nasty contaminants in your glass, but the reverse osmosis process also eliminates healthy minerals, while also leaving the solution a little acidic. 

The AlcaPure solves this issue with a calcium and magnesium post-filter that adjusts the pH level to between 7 and 8, a beneficial alkalinity. The taste is enhanced, too, so you’re sure to notice the difference between this and other countertop RO systems that aim solely for low TDS. We should add this AlcaPure system can fit their other variant of post-filter, the OnliPure, which does indeed drop the TDS to zero!

All packed neatly in a slender silver casing, with sky blue panels and BPA-free tank, this is a unit that will fit into any décor, whether that’s a kitchen, lounge or office. Just plug in and purify! It will work through around 50 gallons per day (GPD), which is more than enough for a typical family.

There are 4 stages of filtration, beginning with a sediment and CB filter. Water is then promptly pushed through the RO membrane, eliminating metals, salts and countless other impurities. Lastly, the ingenious calcium post-filter re-alkalizes what remains.

The LED ring will let you know when to replace filters, though there aren’t specific indicators for each filter. This shouldn’t be a problem, as filters are routinely replaced at similar times, every 12 months for the pre and post-filters, and 2 years for the membrane.

A countertop RO system that also mineralize your H20 isn’t a guarantee, unless of course you’re wise enough to choose the AlcaPure.

Best for Small Spaces: Crystal Quest Countertop RO

PURIFICATION: 10-stage

FLOW RATE: 50 gallons per day; 2.1 gallons per hour

DRAIN RATIO: 1:1

PRICE: $

PROS: Astounding 10-stage purification; incredibly portable; no installation; US-made with 30+ years of experience; no electricity required

CONS: Rated for pressures of 45 psi and up; unrefined aesthetic

The Crystal Quest Countertop RO has a huge 10-stage purification process, so sorry if this starts to get a little confusing. We won’t go into the entirety of the system, lest you go insane, but you’ll no doubt be left with ultra-pure drinking water. 

Their sediment filter has a pore size of one micron, as opposed to the typical five. They use a granular activated carbon (GAC) filter, extremely effective for soaking up lots of chemicals, such as VOCs and THMs. After that, another filter puts the water through the process of electrochemical oxidation. Then there’s more micron pads, GACs and even an ion exchange resin for reducing heavy metals. Honestly, this RO system is as baffling as it is effective. 

Considering how much purification actually goes on, it’s impressive that the Crystal Quest Countertop RO will produce 50 gallons per day. It will almost always prove more versatile in a motorhome, trailer, or comparably demanding space. 

This RO system is raw, barebones purification. Fancy LED displays and unnecessary features are forgotten, in favour of incredibly high functionality. It doesn’t even run off electricity, so you’ll only need a standard faucet to get going.

Practicality is high priority, with the Crystal Quest, as is completely unmatched water purity.

BUYING ADVICE FOR COUNTERTOP REVERSE OSMOSIS SYSTEMS

Purification Stages

Countertop RO systems typically have a 4-stage process, which will include 2 pre-filters, the RO membrane itself and some form of post-filter. This is more than enough to purify your water, though filters may need to be replaced more frequently when compared to 5-stage under-sink equivalents

PRE-FILTERS: Countertop products usually make use of the same kinds of pre-filters, but some may utilize other types to the same effect:

  • A polypropylene (PP) filter, or sediment filter, mechanically removes larger particles, such as sand, dirt and rust. 

  • The carbon block (CB) filter is made from a solid block of compressed carbon, which is often derived from coconut shell. Carbon is an immensely porous material, meaning it will absorb many contaminants, including chlorine.

  • A composite filter (CF) is typically a combination of PP cotton layers with activated carbon. The water still goes through unique stages, it’s just that two filters are presented as one.

  • A granular activated carbon (GAC) filter is made from organic materials high in carbon, such as coconut shell or charcoal. While CB filters are compressed, GAC filters have loose carbon granules. They both achieve a similar result, removing unpleasant smells and tastes, though carbon blocks are often more favourable.

REVERSE OSMOSIS MEMBRANE: The heart of the RO system, your RO membrane is a semipermeable layer, which just means a solvent (water) will fit through, whilst solutes (contaminants) cannot. These membranes have a pore size of 0.0001 microns, unless otherwise stated. Pre-filters are important for preserving this more valuable component of the system, as is regularly replacing them.

Impurities

It’s a well-known stat that a third of the world’s population goes without safe drinking water, but it’s estimated that as many as 63 million US residents, a fifth of the population, is exposed to potentially dangerous sources. In fact, a third of US water distribution structures still have lead service lines. 

Reverse Osmosis systems tackle a huge number of contaminants, including:

  • Aqueous salts: sodium, chlorine, chloramine, nitrate, etc. 

  • Metal ions: lead, copper, arsenic, zinc, nickel, chromium, etc. 

  • Volatile Organic Compounds (VOCs): formaldehyde, benzene, trihalomethanes (THMs), Methylene Chloride, etc. 

  • PFAS: the term for a range of chemicals, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)

  • Pathogens: giardia lamblia, cryptosporidium, etc. 

  • Sediment: dirt, soil, rust, debris, etc. 

Many RO systems boast a 99.9% reduction of heavy metals and salts. These claims are not just good marketing, but a reflection of the incredible science behind reverse osmosis. As many manufacturers use third-party RO membranes, the level of purity is more or less the same.

If you are in an area with abnormally high TDS or exposure to pollutants, countertop RO systems aren’t suitable. Instead, you should consider point of use (POU) systems, i.e. under-sink, or even whole house options.

Health Certification 

Manufacturers may or may not let you know if their products meet the National Sanitation Foundation (NSF) food safety and sanitation standards. This applies to the raw materials that manufacturers use to produce their countertop RO systems, for example BPA-free plastics. 

Certifications cover many areas, but here are some that specifically relate to water filtration:

  • NSF42 (Aesthetic Effects): Reduction of chlorine, chloramine, iron, manganese, zinc (among others) and the reduction of bad taste and odor

  • NSF53 (Health Effects): The reduction of over 50 contaminants, the most popular including lead, Cryptosporidium, VOCs and chromium

  • NSF401 (Incidental Contaminants): Reduction of specific compounds, including prescription drugs, over-the-counter medications, herbicides, pesticides and chemical compounds.

AESTHETIC EFFECTS: taste, odor, color, turbidity, salinity and hardness. They are most commonly influenced by chlorine and metals.

HEALTH EFFECTS: purity, cleanliness, safety. These are influenced by bacteria, parasites, viruses, chemical contaminants, pesticides, herbicides and various others.

Flow Rate

If your countertop RO system connects to a faucet, you will need to worry about the direct relationship between water pressure and flow rate. Municipal water pressure ranges from 45 to 100 psi (3.1 to 6.9 bar), with many RO systems specifically designed to operate under such conditions. Houses with lower pressure will experience problems with their flow rate, in which case a more comprehensive RO system with booster pump may be required. 

However, if your countertop RO system has a manual feed, as many do, you needn’t be concerned with flow rate. In these cases, flow rate is determined by the product itself, namely the built-in electric pump. You can expect countertop flow rate to hover between 50 and 100 gallons per day (GPD), or 2.01 and 4.2 gallons per hour (GPH). 

If the system isn’t connected to a faucet, you should probably be more attentive to tank capacity, as they must be manually refilled. Similarly, if your water consumption is very high, you must consider pure water tank size. Countertop RO products typically have tanks from 1 to 3 gallons, which won’t be enough for high demand scenarios.

Counter Space

Most countertop RO systems are front-dispensing, so you don’t have to worry about additional side and top clearance. Carefully consider the actual product dimensions, however, as they come in all shapes and sizes. 

If especially tight spaces, remember that the feed tank of a manually fed system must be removed and filled. Having to pull out the entire unit can quickly sour the experience. For systems connected to faucets, your options are somewhat limited to the kitchen, as many adapters will only fit standard sizes. 

Measure the space you’re wanting to put an RO system before you make your purchase, in case it ends up being too big. The way in which filters are positioned can make a huge difference to the area taken up by the product, but ultimately the dimensions will tell you whether it’s a good fit.

MORE INFORMATION

If you found this review article useful, then you'll likely love getting a taste of our other water purification content:

Or check out our entire list of Product Reviews or Knowledge Base Articles for more healthy living content.