Looking for a portable or countertop reverse osmosis water filter?
You’ve come to the right place.
Countertop RO systems provide the filtration performance of larger systems without taking up a lot of space.
Unlike full-sized under-sink RO systems, countertop RO filters are much easier to install.
In this in-depth buying guide, we review the best countertop and portable RO water filters and give you tips on how to pick the right one for your needs.
If you are looking for an under-sink RO filter instead, read our reverse osmosis filter reviews for top recommendations.
What is a Countertop Reverse Osmosis System?
There are three types of reverse osmosis filters. The most common are under-sink systems that sit under your sink and produce water from a dedicated faucet on the counter.
You can also get a whole-house RO filter, though these are expensive and hard to find.
The other option is a countertop reverse osmosis system. These are also portable RO systems.
A countertop RO filter is compact and sits on your counter, rather than under the sink. Some have tanks to hold tap water, while others connect to your faucet or the water line under the sink.
Most countertop RO filters have an integrated design. Instead of separate components – filter cartridges, tank and so on – everything is integrated into one housing. This makes installation easier and ensures the system fits on your countertop.
Who Should Consider A Countertop Reverse Osmosis System?
- Anyone who doesn’t have the under-sink space for a full size reverse osmosis system. This includes those living in dorm rooms, RVs, a camper or a tiny home.
- People living in places such as an apartment where you are not allowed to make any plumbing modifications. You can still get RO purified water using a countertop RO system. It doesn’t require any plumbing.
- People who don’t want the hassle of plumbing an under sink RO system.A portable/countertop RO water filter is super easy to install. If installing an under-sink RO system scares you (it shouldn’t, though – it’s easy), a countertop filter is a good choice. It essentially doesn’t require any major installation.
- Anyone who wants a temporary RO system.Unlike a plumbed in under sink system, it’s easy to unhook a countertop system from the faucet and go with it to a new house or to your holiday home. Some countertop systems are actually designed to be portable, so you can carry it on your business or leisure trips.
What is in this buying guide
Table of Contents
Best Countertop Reverse Osmosis Systems
- Best overall:AQUA TRU Countertop Water Filtration Purification System
- Smallest: Purosmart High Flow RO System
- Best for alkaline water: APEC RO-CTOP-PHC
- Best Portable: APEC RO-CTOP-C
- Best standalone: Alcapure Zero Installation Purifier RO Countertop Water Filter
- Best Budget: Express Water Countertop Reverse Osmosis Water Filtration System
- Best with UV filter: SimPure Y6
- Best water-saving: KFLOW KFL-ROPOT-180
- Best value: Waterdrop M5-G
Portable RO Water Filter Systems: Comparison Table
AQUA TRU
Filter Stages:
4Output:
1 gallon/12-15 minsReserve Tank:
2.8L (3 quarts)Recovery Rate (% of pure water):
70-75%Annual Cost (Filters):
~$75Certification:
IAPMO CertificationWarranty:
1 year
PuroSmart High Flow RO System
Filter Stages:
2Output:
50 gallons/dayReserve Tank:
No tankRecovery Rate (% of pure water):
Not specifiedAnnual Cost (Filters):
~$80Certification:
NoneWarranty:
1 year
APEC RO-CTOP-PHC
Filter Stages:
4Output:
90 gallons/day (@60psi)Reserve Tank:
No tankRecovery Rate (% of pure water):
33%Annual Cost (Filters):
~$90Certification:
NSF-certified filtersWarranty:
1 year
APEC RO-CTOP-C
Filter Stages:
4Output:
90 gallons/day (@60psi)Reserve Tank:
No tankRecovery Rate (% of pure water):
33%Annual Cost (Filters):
~$90Certification:
NSF-certified filtersWarranty:
1 year
AlcaPure
Filter Stages:
4Output:
0.5 gallons/15 minsReserve Tank:
0.5 gallonsRecovery Rate (% of pure water):
50%Annual Cost (Filters):
~$90Certification:
NoneWarranty:
1 year
Express Water Countertop RO System
Filter Stages:
4Output:
3-4 gallons/hourReserve Tank:
No tankRecovery Rate (% of pure water):
Not specifiedAnnual Cost (Filters):
~$100Certification:
NSF standard 58Warranty:
1 year
SimPure Y6
Filter Stages:
3 + UVOutput:
418 gallons/dayReserve Tank:
4 litersRecovery Rate (% of pure water):
83%Annual Cost (Filters):
~$52Certification:
NoneWarranty:
1yr (2yrs with registration)
KFLOW KFL-ROPOT-180
Filter Stages:
4Output:
Not specifiedReserve Tank:
Not specifiedRecovery Rate (% of pure water):
Not specifiedAnnual Cost (Filters):
~$155Certification:
NoneWarranty:
30 days
Waterdrop M5-G
Filter Stages:
5Output:
50 gallons/dayReserve Tank:
80oz pitcherRecovery Rate (% of pure water):
40%Annual Cost (Filters):
~$70Certification:
NoneWarranty:
30 day guarantee
Portable RO Water Filters: Reviews
The AQUA TRU 4-stage water purification system is the best countertop RO filter for most people. It provides high-performance 4-stage filtration, has a strong flow rate, and requires no plumbing.
PROS
- No installation.
- Fast flow rate.
- High filtration performance – removes over 90% of impurities in water.
- Great tasting water.
- Filter change reminder.
CONS
- It’s bulky – not ideal for small countertops.
- Pricey
OUR REVIEW
KEY FEATURES
1. No plumbing
You don’t need to connect the system to your faucet. It comes with a large tank where you add tap water to be filtered.
This design is especially helpful if you live in a home where you cannot do any plumbing modifications.
2. 4-stage Filtration
The Aqua Tru system removes over 90% of impurities in water using four filters.
- A pre-filter removes dust, sediment, and water turbidity (cloudiness).
- An activated carbon filter removes chlorine, chloramine, and other chemicals.
- An RO membrane removes TDS, heavy metals, cysts, and microbes.
- A carbon post-filter removes any remaining odors and tastes.
3. Fast flow rate
Most people associate RO systems with slow-flowing water. Aqua Tru is different. Water flows from the 2.8-liter tank almost as fast as a normal tap.
4. High recovery rate = less water wasted
Compared to under-sink RO filters that waste up to 80% of water, the Aqua Tru system is very efficient. It uses only 25-30% of water to flush the filters, giving it an impressive 70-75% recovery rate.
5. Long-lasting filters
For such a compact system, the filters last surprisingly long.
For an average family using city water, the pre-filter lasts about 6 months, the carbon filters one year, and the RO membrane two years. Yearly costs are lower as compared to other RO water filters.
6. Quick change filters
The system will remind you when it’s time to replace the filters. It takes less than two minutes to remove the old filter cartridges and put new ones in.
ISSUES & LIMITATIONS
1. Pricey
The Aqua True RO filter is one of the most expensive countertop RO systems. It costs about twice as much as other popular portable RO filters.
BOTTOM LINE
Aqua Tru is a great choice for anyone looking for a no-installation countertop RO filter with a high flow rate.
If you are short on counter space, the PuroSmart RO system is a great choice. It takes up very little space on the counter. It’s perfect for tiny homes, RVs, apartments, and dorm rooms.
PROS
- Space saver.
- Easy to set up.
- Great tasting water.
- Removes heavy metals, microbes, and most other impurities.
- Good flow rate.
CONS
- High maintenance costs.
Our Review
KEY FEATURES
1. 2-stage filtration
For its price and size, it’s not surprising that the PuroSmart system has only two filtration stages rather than the usual four you get with most countertop RO filters.
But the carbon filter and the RO membrane do a great job removing almost all contaminants, including sediment, chlorine, VOCs, TDS, and microbes.
The only downside is that the filters don’t last long.
2. Easy Setup
The PuroSmart filter comes with a complete installation kit that includes a diverter valve, faucet adapter, tubing, and a countertop stand.
To install it, remove the aerator on your faucet and attach the adapter. Connect the tubing from the adapter to the filter and enjoy great-tasting purified water.
The water comes out faster than in most RO systems, which is likely because there are only two filters for water to pass through.
The exact flow rate will depend on the pressure of water out of your faucet. With good pressure, the system purifies up to 50 gallons of water a day.
3. Small Footprint
PuroSmart is one of the smallest countertop RO filters you’ll find. It comes with a stand that sits right next to the sink.
No matter how small or crowded your countertop is, the PuroSmart filter will fit.
ISSUES & LIMITATIONS
1. Frequent filter changes
The carbon pre-filter lasts only three months. That’s because it has to remove a lot more impurities than filters in a 4-stage system.
The sediment quickly clogs the carbon filter, reducing its effectiveness.
The RO membrane also doesn’t last as long as in other RO filters: just 1-2 years vs. the standard 2-3 years.
Frequent filter changes mean higher maintenance costs. That’s why PuroSmart, a small, low-cost RO system, costs about as much to maintain as the higher-priced and much bigger Aqua Tru system.
BOTTOM LINE
PuroSmart is a great choice for homes with little countertop space, as well as RVs, boats, and dorm rooms.
If you are looking for an RO system that produces great-tasting mineral alkaline water, we recommend APEC RO-CTOP-PHC.
The RO-CTOP-PHC is a compact RO filter that you can set up on your kitchen countertop or carry with you for use away from home.
PROS
- Set up in minutes.
- High-performance 4-stage Filtration.
- Includes an aluminum case for aesthetics and portability.
- Small footprint.
- High daily output.
CONS
- Slow flow rate
Our Review
KEY FEATURES
1. 4-stage filtration (with mineral filter)
The RO-CTOP-PHC system consists of four filters, one of which is a mineral filter.
- A 5-micron sediment filter gets rid of dust, sediment, and rust.
- An activated carbon filter removes chemicals like chlorine and VOCs that cause odors and tastes.
- A high-rejection RO membrane removes up to 99% of total dissolved solids, including heavy metals. It also removes bacteria and viruses.
- A calcium carbonate filter adds calcium to the water, increasing its pH, and improving the taste.
2. With & Without Case
The last ‘C’ in RO-CTOP-PHC indicates that the filter comes with an aluminum case. The case is mostly for aesthetic reasons – it hides the tubing and cartridges – but it also helps with portability.
If you don’t want to pay extra for the case, get the RO-CTOP-PH model.
3. Easy Installation
The RO-CTOP-PHC is super easy to install. Remove your aerator, attach the included adapter to your faucet, and connect the tubing.
The RO-CTOP-PHC RO system works with all standard faucets.
4. The relatively high recovery rate
For an RO system without a pump, the RO-CTOP-PHC is surprisingly efficient. It has a pure to wastewater ratio of about 1:2, which means it recovers about 33% of pure water.
This is much better than the 1:3 or 1:4 ratio of most RO systems.
ISSUES & LIMITATIONS
1. Slow flow rate
Because there’s no built-in reserve tank, filling a glass directly from the filter takes forever. You are better off storing pure water in a jug or large bottle for easier access.
If you already have low water pressure in your home, the flow rate out of the RO-CTOP-PHC outlet tube is going to be even slower.
BOTTOM LINE
The RO-CTOP-PHC portable RO system is a great choice for anyone looking for a countertop RO filter that produces alkaline mineral water.
The APEC RO-CTOP-C is a cheaper alternative to the APEC RO-CTOP-PHC RO filter. The RO-CTOP-C lacks a mineral filter but contains a carbon post-filter, which is not present in the RO-CTOP-PHC model.
Even without the mineral filter, the water tastes great. The carbon pre-filter and post-filter do a great job eliminating all tastes and odors from the water.
PROS
- Easy to set up.
- Great-tasting water.
- Includes cases for aesthetics and easy portability.
- High-performance 4-stage Filtration.
- High daily output (90 GPD).
CONS
- Slow water production.
Our Review
KEY FEATURES
1. The compact 4-stage RO system
The only difference between the APEC RO-CTOP-C and RO-CTOP-PHC is the last stage. Instead of a mineral filter, the APEC RO-CTOP-C ends with a coconut shell post-filter.
Here are the four stages.
- A fine mechanical filter removes dust, sediment, and other particulates that cause water cloudiness.
- A coconut shell carbon filter removes chemicals that cause odors and tastes in the water, including chlorine and VOCs.
- A high-rejection RO membrane filters out up to 99% of TDS, including mercury, arsenic, lead, and radium. It also removes bacteria and viruses.
- A carbon post-filter, also made from coconut shell, removes any remaining tastes and odors.
2. 90 GPD Output
Despite its compact size, the APEC RO-CTOP-C can produce enough water to meet the needs of most families.
It can output up to 90 gallons per day. But your faucet water pressure needs to be adequate to achieve the max daily output. The 90 GPD output is at a pressure of 60 psi.
It’ll still work with lower water pressure (minimum 30 psi), but the daily output will be less. At 50 psi, it will filter up to 75 gallons a day, still plenty of drinking water for a large family.
If your water pressure is very low, consider installing a booster pump.
3. Cased and Uncased Options
Like the APEC RO-CTOP-PHC, you can also get the RO-CTOP-C with and without a case. The slightly cheaper uncased model is labeled as RO-CTOP.
But we think the extra cost is worth it for the cased model. It looks better on your countertop and makes it much easier to carry the filter system with you when traveling.
4. Compatible with Most Faucets
APEC RO-CTOP-C is compatible with most standard faucets apart from the sprayer and pull-out faucets.
To install it, remove the aerator from your faucet and use the included adaptor to attach tubing to the faucet.
ISSUES & LIMITATIONS
1. Low Flow rate
Similar to the other RO-CTOP filters, the RO-CTOP-C produces filtered water at a relatively slow rate.
If your faucet water pressure is high, the flow rate is decent but still not as fast as that of the AQUA TRU countertop filter.
If you have a lower faucet water pressure, it’s better to store the filtered water in a jug or large bottle for easier access when you need drinking water.
BOTTOM LINE
The APEC RO-CTOP-C is a great choice for anyone looking for a high-performance and highly portable RO water filter.
If you want a completely standalone RO filter that doesn’t connect to your faucet, the AlcaPure purifier is a great choice.
It’s very similar to Aqua Tru and costs about the same.
The two biggest advantages of standalone systems like AlcaPure and Aqua Tru is the high flow rate (they use an electric booster pump) and the water savings.
PROS
- No installation.
- High recovery rate.
- High-performance 4-stage Filtration.
- Produces alkaline water.
- Filter replacement reminder.
CONS
- More expensive than faucet-mounted filters.
Our Review
KEY FEATURES
1. Zero Installation
If you don’t want to modify your faucet in any way, such as adding a diverter valve, the AlcaPure system is a good choice.
Instead of connecting to your faucet, it has a built-in reservoir where you add a gallon of tap water.
The system is ready to use out of the box. No plumbing needed.
2. 4-stage Filtration
The AlcaPure system has 4 filters integrated into it.
- A 5-micron sediment filter removes water turbidity.
- An activated carbon filter removes chemicals like chlorine, pharmaceuticals, pesticides, and VOCs.
- A reverse osmosis membrane filters out microbes and dissolved solids such as arsenic, fluoride, and lead.
- An alkaline carbon post-filter removes remnant odors and tastes and adds a bit of calcium and magnesium back to the water. Remineralization improves the taste of water and increases its pH.
3. High Recovery Rate
AlcaPure’s recovery rate of 50% is not as good as Aqua Tru’s 75%. But it’s much better than what you get from non-electric RO systems (25-33%).
Thanks to the built-in booster pump, AlcaPure saves you more water and increases the output flow rate so you can fill a glass of water in seconds.
ISSUES & LIMITATIONS
1. Pricey
The AlcaPure countertop RO system costs about twice as much as a faucet-mounted RO system.
BOTTOM LINE
AlcaPure is a great choice for anyone looking for a zero-installation countertop RO system. AlcaPure is also a good choice for anyone looking for a portable RO system that produces alkaline water.
The Express Water countertop RO filter provides high-performance 4-stage filtration. It connects directly to your faucet and comes with a dedicated purified water faucet.
It is one of the cheaper portable RO filters available online, but the cost of replacement filters adds up quickly.
PROS
- Removes almost all contaminants from water.
- Affordable pricing.
- Produces filtered water from a faucet instead of a tube. A faucet looks better and is easier to use.
- Easy to install.
CONS
- More expensive to maintain compared to other portable RO systems.
- Low water flow rate.
- Low recovery rate.
Our Review
KEY FEATURES
1. 4-stage filtration
The Express Water system has a standard 4-stage filtration system.
- Sediment filter – dirt, rust, sand, and dust
- GAC carbon filter – chlorine, VOCs and other chemicals
- RO membrane – TDS, arsenic, fluoride, lead, bacteria and viruses
- Polishing carbon filter – odors and tastes
2. Easy setup
The Express Water RO system comes with everything you need to set it up.
It connects directly to your faucet using one of the included adaptors. Note that it is not compatible with pull-out and sprayer faucets.
One thing we like about the Express Water system is that it produces purified water from a dedicated faucet instead of a tube. It looks neater and more professional. It also makes it easier to fill a cup or jug with water.
ISSUES & LIMITATIONS
1. Slow flow rate
Similar to other non-electric RO systems, the Express Water RO filter produces purified water at a little more than a trickle.
It takes about 10-15 minutes to get a gallon of purified water.
2. Low recovery rate
Again, this is a limitation shared with other non-electric portable RO systems. You’ll notice there’s more drain water than purified water.
Though the manufacturer has not indicated a specific waste to pure water ratio, it’s typically 3:1 for such systems.
But you don’t have to throw out the drain water. It’s safe for watering plants.
3. Higher maintenance costs
Another issue we have with the Express Water system is the frequent filter replacements. Most portable RO filters typically need one filter change a year. Express Water filters need to be changed twice a year and the membrane once a year.
This brings the annual cost to about $100 (the cost of a 1-year filter set from Express Water), the highest among our picks.
BOTTOM LINE
The Express Water RO system is a great choice for anyone looking for an affordable faucet-mounted countertop RO filter.
PROS
- 3-stage filtration + UV lamp.
- High water efficiency and flow rate.
- No installation.
- Filter change reminder.
- Compact space-saving design.
CONS
- Pricey.
Our Review
KEY FEATURES
1. 3-stage filtration
The SimPure Y6 has a standard filter configuration. First is a sediment filter that traps large particulates. Next, an activated carbon filter removes finer particles as well as chlorine and other chemicals.
An RO membrane deals with the tougher pollutants like microbes, heavy metals and fluoride.
Combined, the three filters can remove over a thousand different types of impurities. So regardless of whatever stuff is in your water, the SimPure Y6 will take it out.
2. UV Lamp
In addition to the three filters, the SimPure Y6 has an additional defence against impurities, specifically microorganisms.
A UV lamp sterilizes any viruses, bacteria and cysts that manage to pass through the RO membrane, ensuring your water is truly pure and safe to drink.
3. High Efficiency and Flow Rate
The SimPure Y6 is one of the best water-saving countertop RO filters. It has a pure to drain water ratio of 5:1. That means it drains just 1 gallon of water for every five gallons of purified water.
Something else we love about the Y6 is how fast the water flows out of the outlet. It’s not as fast as a kitchen faucet, but much better than most countertop RO filters. It takes just 15 secs to fill a cup and about a minute to get a litre of water.
4. No Installation
The SimPure Y6 is a plug and play system. You don’t even need to connect it to your faucet. Simply fill up the 5-liter water tank, plug it in and turn it on.
Maintenance is also easy. The control panel will alert you when it’s time to change the filters – usually after 6-12 months depending on your consumption and water quality.
ISSUES & LIMITATIONS
1. Pricey
Similar to other electric countertop RO filters, the SimPure Y6 doesn’t come cheap. But we think it’s worth it.
BOTTOM LINE
PROS
- Water saving.
- High-performance 3-stage filtration.
- Long filter life.
- Easy filter replacement.
CONS
- Expensive.
Our Review
KEY FEATURES
1. 4-stage filtration
The KFLOW RO filter passes water through four stages of filtration to remove over 99% of contaminants.
This includes two pre-filters: a sediment filter for large particulates and an active carbon filter to remove tastes, odors and organic impurities.
An RO membrane removes salts, heavy metals, and microbes. The final carbon filter polishes the water to ensure all tastes and odors are gone.
The only missing stage is a mineral filter, but you can easily add minerals to your drinking water.
2. Water-saving
Being an electric pump-driven RO system, the KFLOW KFL-ROPOT-180 is already a water saver. It wastes less water compared to non-electric filters.
There’s another way it saves water, and we haven’t seen this in any other countertop or under-sink RO system. The KFLOW RO filter recycles waste water to extract more pure water from it.
Once you fill up the tank, the system will purify it and return waste water back into the tank. You can run this water again through the filters up to 4 times before you throw it out. Each time, the system reduces the amount of waste water.
3. Easy Installation & Maintenance
The KFLOW KFL-ROPOT-180 requires no installation. Just fill it with water and plug it in. Maintenance is also easy. You’ll receive an alert when it’s time to get new filters. The filters take less than 30 seconds to replace with no tools required.
Despite the recirculation feature, the KFLOW filters last longer than in most countertop systems. The RO membrane is good for 2 years (instead of the usual one year), while the other three filters last 1 year instead of the typical 6 months.
ISSUES & LIMITATIONS
1. Expensive
If you are shopping on a budget, the KFLOW KFL-ROPOT-180 may not be what you are looking for. It costs quite a bit more compared to non-electric and under-sink RO filters.
Replacement filters are also not cheap. Replacing the four stages will cost you roughly $155 a year.
BOTTOM LINE
If you are looking for a cheaper RO filter that will purify your drinking water just as well as the pricier systems, we recommend the Waterdrop M5-G.
The M5-G is non-electric, hence the lower price. That means you have to connect it to your faucet and the flow rate is a bit slow.
But it removes impurities just as well as any other RO filter.
PROS
- Low price.
- 5-stage filtration.
- Doesn't need to be plugged in.
- Comes with a water pitcher.
- Easy to replace all-in-one filter.
CONS
- Slow flow rate.
- Takes time to install.
Our Review
KEY FEATURES
1. All-in-One 5-Stage Filtration
The Waterdrop M5-G has more filters than most other countertop systems – 5 instead of the usual 3.
These include three prefilters: two sediment filters and a carbon filter. The prefilters remove dust, sand, rust, chlorine and various chemicals from the water. This clears up the water’s taste, smell and color, and protects the RO membrane from damage.
The RO membrane takes out heavy metals and microbes, while the post carbon filter removes any remnant tastes and odors.
Unlike other RO systems ,the M5-G uses an all-in-one design. All the five filters are in a single housing. This makes filter replacement super easy. Just remove the old cartridge and insert the new one.
You’ll need to replace the filter cartridge once a year.
2. Non-electric
If you are looking for a countertop RO filter that you don’t need to plug in, the Waterdrop M5-G is a great choice.
It is non-electric; it works exactly like under-sink systems. Pressure from your water line drives water through the filters.
Being non-electric makes the M5-G cheaper, makes it silent, and eliminates the need to have an outlet within reach.
3. Comes With Water Pitcher
The Waterdrop M5-G stores purified water in a pitcher that’s included in the pack. The pitcher doesn’t have an outlet tube or faucet. To drink water you detach the pitcher and pour water into a glass.
Once the pitcher fills up, you can also remove and store it in the refrigerator.
The 80 oz pitcher is a bit small for a family, so you may want to get additional pitchers to store more water.
ISSUES & LIMITATIONS
1. Installation Takes Time
While it’s a countertop RO filter, the M5-G connects to your water line and drainage under the sink. This makes installation a bit tedious and time consuming.
The most difficult part of installation is drilling a small hole in your counter to run the inlet and drain tubes through. You also need to drill a hole in your drain pipe for the drain tube.
If you are looking for a zero-installation RO filter or one that takes 5 minutes to install, we don’t recommend the Waterdrop M5-G. Get an electric or faucet-connected RO filter instead.
2. Low Flow Rate
Being non-electric has its advantages, which we mentioned above. It also has one major downside; the system is slow.
It takes 15-20 minutes to fill the 80oz pitcher.
That’s why the daily capacity of the M5-G is just 50 GPD, compared to the 400+ GPD of electric countertop RO filters.
For this reason, we recommend the M5-G only for small households of 1-4 people. It’s also a great choice if you want an RO system just for making baby formula or some other specific use.
BOTTOM LINE
If you don’t mind the slow filtration rate, the Waterdrop M5-G is a great bargain.
Portable RO Water Filter Technology
Portable RO water filters are miniaturized versions of full-size under-sink RO systems. There’s no major difference between how an under-sink RO filter works and how a countertop system works.
Like an under-sink filter, countertop RO filters have multiple stages consisting of different filter media.
Most consist of 4 stages.
The first stage (pre-filter): Typically, a sediment filter to remove sand, rust, and other particulates.
The second stage (chemical pre-filter): Usually, an activated carbon filter to remove chlorine and other chemicals and condition the water before it passes through the membrane.
Third stage (purification): This is usually the RO membrane where the toughest contaminants like heavy metals and bacteria are removed.
Fourth stage (post-filter): The last stage polishes the water to remove remnant odors and tastes.
Some RO systems also include a mineral filter that adds back some of the stripped minerals to improve the taste of water and increase alkalinity.
Other components of portable RO water filters include:
- Booster pump – only in electric systems.
- Tanks – also found mostly in electric countertop systems.
- Faucet adapter valve and tubing – used in faucet-mounted systems.
Portable RO Water Filter Installation
Portable RO water filters are easy to set up. There are two types of portable RO systems with different setup processes.
Faucet-mount Reverse Osmosis Filters
- Install the filter cartridges if they are not already installed. Follow the manufacturer’s instructions to make sure you install filters in the right order.
- Remove the aerator from your faucet and attach the included adaptor and valve. Most manufacturers include two or more adapters for different faucet sizes.
- Attach the tubing. This includes the tube that takes water from the faucet to the RO system and the outlet tube where purified water comes out. Some systems also have a drain tubing, which you can place in the sink or in a jar to collect the wastewater.
- Flush the system 2-3 times before you drink water from it.
Standalone Countertop Reverse Osmosis Filters
Standalone countertop RO systems don’t require any installation. Just assemble the filters, fill the unfiltered water tank, plug the system into an outlet, and flush it 2-3 times.
Please note:
- Never run hot water through an RO system. It will damage the filters.
- Make sure your tap water is within the recommended pressure range (usually indicated in psi). If it’s too low, water will come out of the RO system in a trickle or droplets. If it’s too high, it will damage the filters.
- Replace the filters as recommended. For most systems, the pre-filters and post-filter last 6-12 months while the RO membrane lasts 1-2 years.
Benefits of Portable RO Water Filters
Portability: This is obviously the biggest advantage of portable RO water filters. You can use it at home, in your RV, in a hotel room, at a friend’s house or when camping.
Easy or no installation: It takes less than 10 minutes to install a faucet-mounted system. A standalone countertop model requires no installation.
Cheaper than full-size RO systems: Most portable RO systems are cheaper than full-size under-sink filters. Electric standalone systems are the exception. Many cost more than most under-sink RO systems.
Space-savers: Countertop RO filters take up very little space on your counter, making them ideal for small kitchens, RVs, and boats.
No under-sink space needed: Have no space under your sink? No problem. Portable filters sit on the countertop. They are great if your building doesn’t allow any plumbing work. They are also ideal for RVs and dorm rooms.
Portable RO Water Filter Systems: Complaints & Flaws
Here are the most common issues you are likely to encounter when using a portable RO water filter.
Slow water output: Faucet-mounted RO systems produce water in a weak stream that takes forever to fill your glass. Electric countertop systems have a much stronger flow rate since they have a built-in pump.
Fewer filters = more frequent filter replacements: Most under-sink RO systems have five stages. Five filters handle all the impurities in water. Portable RO systems usually have four stages, meaning there are fewer filters to remove the impurities. The result is that you have to replace the filters more frequently, which increases yearly maintenance costs.
Portable RO Water Filter Replacement
It typically takes less than five minutes to replace filters on a portable RO system. With most models, you twist the cartridge then pull it out. Put in the new cartridge and twist to secure.
Check your manual for exact filter replacement instructions. Also, check how often you should replace the filters.
If you get an electric countertop RO filter, you don’t need to remember to replace the filters. The system will remind you when it’s time.
Portable RO Water Filters: Frequently Asked Questions
What contaminants do portable RO water filters remove?
Portable RO filters remove the same impurities as under-sink RO filters: chlorine, VOCs, pesticides, lead, fluoride, arsenic, hardness minerals, bacteria, and viruses, among others.
How long do portable RO water filters last?
The pre-filter and post-filter typically last 6-12 months while the membrane needs to be replaced every 1-2 years.
Are portable RO water filters easy to install?
Yes, you can install a faucet-mounted RO system in under 10 minutes. If you get an electric countertop RO system, you don’t need to install it. Just add water to the tank and press a button to get purified water.
Can I use a portable RO water filter with well water?
Yes, you can, but it will significantly reduce the filter lifespan. We recommend installing a whole-house water softener before using a portable RO system for drinking water.
Bottom Line
A countertop reverse osmosis water filter is a convenient and space-saving alternative to a large under-sink system.
Hopefully, our buying guide has helped you find the right one for your needs.
