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Best Countertop Reverse Osmosis System / Water Filter

Jennifer Hansen
Last Updated on
by Jennifer Hansen

Continuous clean drinking water requires a perfect water filter system; however, a standard carbon-based filter will not filter all harmful contaminants. Reverse osmosis filters will, though.

Reverse osmosis, often referred to as RO, is a filtration process that uses technology to force water through tiny pores of a semi-permeable membrane to eliminate contaminants and produce highly purified water. While standard carbon-based filters will remove chlorine and other chemicals, an RO system filters out all contaminants, including heavy metals and bacteria, filtering to a much higher degree than an ordinary filter.

Countertop water filters are convenient and fit well in most spaces, and some are portable, so you can take them with you when you travel. Here are some benefits:

  • Hassle-free installation
  • Don’t require alteration of plumbing systems
  • Minimal maintenance
  • Typically compact and lightweight
  • Perfect for traveling

Countertop RO systems are a win-win, but with so many on the market today, how do you know you are choosing one that fits you and your home?

Check out our top five best countertop reverse osmosis filtration systems, along with our buying guide.

Best Countertop Reverse Osmosis Water Filters
Aquatru Countertop RO Filter
  • Filter Stages: 4
  • Dimensions (inches): 14 x 14 x 12
  • Weight (lbs): 16.3
Waterdrop reverse osmosis filter
Best Tankless System
  • Filter Stages: 7
  • Dimensions (inches): 18.1 x 5.7 x 17.8
  • Weight (lbs): 15.44
  • Filter Stages: 4
  • Dimensions (inches): 18 x 7.5 x 15.5
  • Weight (lbs): 19.9
  • Filter Stages: 4
  • Dimensions (inches): 21 x 18 x 14.25
  • Weight (lbs): 23.4
  • Filter Stages: 4
  • Dimensions (inches): 14 x 6 x 6.5
  • Weight (lbs): 7

The Best Countertop Reverse Osmosis Water Filters That We Recommend

1. AquaTru Countertop Reverse Osmosis Water System – Best Choice

Aquatru Countertop RO Filter

AquaTru is currently the first and only countertop reverse osmosis system NSF certified to remove 82 contaminants, including lead, chromium, chlorine, fluoride, PFAs, and more. This is 15 times more than most leading pitcher filters. The patented Ultra Reverse Osmosis Technology is the same technology that all major bottled water brands use.

The high-quality performance of AquaTru RO made it our first choice in the Best Countertop System.

 Benefits of this Filter:

  • Sleek, modern look
  • Removable dispensary tank to store in refrigerator
  • Produces one gallon every 12-15 minutes
  • Four-stage Ultra Reverse Osmosis filtration
  • NSF certified to remove 82 contaminants
  • 3:1 drain ratio
  • Quick-change filters last up to two years
  • Digital display to indicate filter changes
  • One year warranty

The power behind AquaTru is in the four-stage Ultra Reverse Osmosis process. The mechanical pre-filter starts the filtration by removing sediments and cloudiness. The activated Carbon Pre-filter then removes more than 99% of chlorine and chloramines. Stage three is the High-Efficient RO filter that destroys toxic inorganic contaminants, including lead and chromium 6.

Finally, the Activated Coconut Shell Carbon VOC filter eliminates toxic organic chemicals, ensuring pure and great-tasting water.

AquaTru comes pre-assembled, making installation easy. The long-lasting filters are also a perk. You will replace the pre-filter and VOC filter every 600 gallons (approximately 6-12 months, depending on use), and the RO filter every 1200 gallons or two years. This system is pleasing to the eye; it sits nicely on your countertop and provides a sleek, modern look to complement your kitchen.

Unlike some portable RO water filters, the AquaTru does not attach directly to your faucet. Instead, the one-gallon feed tank is manually filled and attached to the unit.

This system has a water waste ratio of 3:1, which is low for RO systems. While the cost may seem a bit high, the benefits and quality of this system make it well worth it for most people.

  • NSF certified for removal of 82 contaminants
  • Comes pre-assembled
  • BPA free construction
  • Durable, long-lasting filters
  • Nice look that will complement your kitchen
  • Cost may be a deterrent
  • Plastic tanks are prone to scratches

2. Waterdrop WD-G3-W – Best Tankless System


Tankless Reverse Osmosis systems are the ultimate convenience that serve on-demand water like a water fountain. The maximum capacity for these systems is significantly higher than standard RO systems.

For example, a standard RO countertop system boasts a 100 GPD; the Waterdrop G3 System produces an impressive 400 gallons per day of filtered, great-tasting water!

Benefits of this System:

  • Seven-stage deep filtration
  • Unique tankless design
  • Smart faucet to display water quality
  • 1:1 drain ratio
  • Automatic flushing
  • Bacteria and virus removal
  • 400 GPD: fast water flow
  • Digital display to indicate filter changes
  • Built-in leakage protector

As far as tankless RO systems, the Waterdrop is a trendsetter. The seven stages (yes, seven!) employ a cotton and carbon block, a huge RO membrane, and a post-activated carbon filter to remove chlorine, sand, rust, solids, taste, odor, while reducing TDS, limescale, heavy metals, bacteria, viruses, and more than 1,000 other contaminants.

One of the most impressive benefits is the 400 gallons per day capacity and one cup of water every 12 seconds. The smart design faucet displays the water’s quality in real-time, and the Smart TDS monitor shows you when you need to replace the filters. The filters need replacing between 6 months and two years. Because of the fast flow rate, this system does require electricity.

The Waterdrop G3 comes with all you need for a simple installation, including the system housing, the three filters, a faucet, a power adaptor, and all the tubing and fittings. The system can be installed in just 30 minutes and the filters in just three seconds! The automatic flushing is also a great feature. The system will initiate flushing after two hours, which eliminates clogs and extends the filter life.

  • NSF 58 and 372 certified
  • Removes 1000+ contaminants
  • Impressive 400 GPD for constant water
  • Best RO tankless design on the market
  • Smart faucet and TDS display
  • Requires electricity
  • Slightly pricier than competitors

3. SimPure Y5 Instant Heat Countertop RO System – Best for Temperature Control


Here is a sleek, compact RO countertop filter that not only removes 99% contaminants in your water but features convenient temperature control, so you can heat and filter your water in one easy step. The SlimPure 75 is a perfect portable reverse osmosis water filter for those who often need to heat water for baby formula, coffee, or tea.

Benefits of this Filter System:

  • Tested against NSF standards
  • Removes 99.9% of 1000+ pollutants
  • Four-stage RO filtration
  • SlimPure UV purification
  • Four temperature settings + instant heat
  • Removable 5L water tank with 1.5 water storage
  • 5:1 drain ratio
  • No installation required
  • LED water quality indicator

The four-stage filtration process includes a 2-in-1 CF composite filter, a 0.0001 micron RO membrane. An activated carbon post-filter effectively removes 99% of more than 1000 contaminants including viruses, bacteria, fluoride, TDS, limescale, heavy metals, lead, chlorine, and more. This filter utilizes UV purification, which is only one of four methods approved by the FDA.

This is only RO system we have reviewed with a temperature setting. The four settings include tea, coffee, low-temperature milk, and normal water temperature, ensuring the perfect amount of warmth, whether you are heating baby formula or making the perfect cup of coffee.

The removable 5-liter tank means you can take it and go, perfect for an office, restaurant, outdoor event, etc. The 5:1 drain ratio saves water up to 1500% compared with typical RO systems. Once this system has filtered a tank of water, the wastewater is left behind, so you will need to dump it out before refilling.

Another great benefit of the SlimPure Y5 is that there is no installation or plumbing needed. All you do is plug it in, and it’s ready to work. The LED display will indicate the quality of your water, as well as the lifespan of the filters. Filters are expected to last 3-6 months, depending on use.

  • Removes 99% of more than 1000 contaminants
  • Tea, coffee, milk powder heating settings
  • Removable 5L tank for convenience
  • No installation/plumbing required
  • Leak-proof
  • Requires electricity
  • Filters don’t last as long as some other RO systems

4. KFLOW (KFL-TDS-180) Reverse Osmosis Countertop Filter System – Best Eco-Friendly Design


Some may not prefer a typical reverse osmosis system because of the inevitable water waste that occurs. Enter the innovative KFLOW Water Filter System, featuring recycling multi-filtration technology so that no water is wasted. Instead, it is recycled for the next round of filtration, saving 300% of water. This innovative eco-friendly technology maximizes efficiency while reducing cost.

Benefits of this Filter:

  • Four-stage 0.0001 micron filtration removes 1000+ contaminants
  • Double RO filter cartridge= tripled water production
  • Intelligent TDS detector monitors
  • Recycling multi-filtration technology
  • No installation required
  • Long-lasting filters

The KFLOW RO system features a four-stage filtration process with an enhanced double RO filter, meaning more water produced while effectively blocking more than 1000 contaminants. This system will remove carcinogens, heavy metals, micro-organic, and inorganic pollutants, while improving taste and odor. The recycling multi-filtration technology saves up to 300% more water when compared to traditional RO units. Instead of dumping out the wastewater, you simply add more water to the tank once a cycle is done, saving time and well, water!

No installation is required for this system. All you do is fill the water tank and press the button. While the default water volume production is 1.7L, you can program this unit to produce 0.5, 1, and 1.5 L at a time. Likewise, the spiral design of the cartridge replacements makes changing them a breeze. No tools required! The intelligent TDS display monitors the water quality in real-time. The PPF and CTO filters have a one-year lifespan, while the RO filter will last two years.

Since this system is not connected to a water supply, it is easily portable and can be taken anywhere with an available power supply. The elegant look matches nicely with its surroundings, whether it is in a living room, kitchen, office, or RV.

  • Four-stage filtration effectively removes 1000+ contaminants
  • Recycling technology means less water waste
  • Intelligent display keeps you updated on quality and filter life
  • No installation needed
  • Long-lasting filters
  • Carry loop is comfortable
  • Unit is larger than others, taking up more space
  • Uses electricity

5. APEC RO-CTOP Portable Countertop RO System – Best Budget Choice


Light and compact, APEC’s RO-CTOP portable countertop RO filter system is one of the best systems out there, and while it’s not cheap, it’s the most budget-friendly pick we have. It will easily pay for itself in 3-6 months, even with a filter change.

Benefits of this System:

  • Designed with high quality certified food-grade materials
  • Four-stage filtration process
  • Compatible with most standard faucets
  • No installation required
  • 90 GPD capacity
  • 40-80 PSI
  • Designed, engineered, and assembled in the USA
  • Perfect for apartments, condos, motor homes

This portable system can be used on most faucets but  won’t work on pull-out faucets, special size designer faucets, or sprayer faucets. It is especially ideal for apartments, condos, motor homes, and those who love to travel. The best thing about this filter is that there is no installation required. You can take in with you and get up to 90 gallons a day of pure, great-tasting drinking water.

APEC’s RO-CTOP features a four-stage reverse osmosis process that removes 99% of contaminants from water. Water flows through the 5-micron sediment filter that removes dust and debris before moving onto stage two, the coconut shell activated carbon filter, which removes chlorine, VOCs, odors, and cloudiness. Stage three, the TFC RO membrane removes up to 99% total dissolved liquids (TD) and contaminants such as arsenic, lead, fluoride, chromium, radium, and more. The water then passes through the final stage, another coconut shell activated carbon filter, to remove any residual tastes, leaving you with safe, pure drinking water.

Everything about APEC’s portable RO filter is simple, including the quick connection fittings and the lightweight filter system. There is no installation required, meaning you need no tools. Just connect it to your faucet, and it’s ready to go. APEC offers a one-year limited warranty on this system, and if you have any issues, customer service is exceptional.

  • Handy for travelers, RV’s, dorm rooms, etc.
  • High-performance four-stage filtration process
  • No installation required
  • Excellent customer service
  • Budget-friendly
  • Does not fit all faucets
  • Low water flow rate

The Buyer’s Checklist: How to Choose the Right Countertop RO System

Countertop Reverse Osmosis Filter

With all the countertop RO systems on the market today, you may be wondering how to choose the right system for you and your household’s needs. The most important aspects are filtration quality, water production, easy installation/setup, and filter life.

Effective Filtration

Most RO countertop filters employ at least four stages of filtration. These include pre-filters (sediment and carbon), a RO membrane, and a post-filter. In addition, some feature other stages, such as a mineral or UV filter. Some filters are NSF certified, meaning it has been third-party tested and meets the quality standards.

Water Production

You don’t want to invest in a water filter just to realize that it doesn’t produce the volume of water you need each day. That’s why it’s important to check the GPD (gallons water per day). For families, we recommend a 75 GPD RO system. Smaller families could use a 50 GPD unit, while larger families will need a 90 GPD or higher system. Also, if you use RO water for other purposes than drinking (gardening, pets), you will need a higher output system.


Sure, if you were installing a whole house filtration system, it may take up half of your day. However, countertop RO filtration systems should be easy to install within minutes. Some units come pre-assembled, so all you need to do is plug them in. There are some that come with faucet connectors, but these should take no more than a minute to screw on. A perk of these systems is their simple setup.

Filter Life

Always check the filter life when looking for a RO system. Short reverse osmosis filter lifespans will raise costs. Note that pre-filters and post-filters will have a different lifespan from the RO membrane filter. A good rule of thumb is at least six months for the pre and post reverse osmosis filters and at least two years for the RO membrane. Some RO membranes can last 3-5 years!

Frequently Asked Questions

Which contaminants do RO countertop systems remove?

RO water filtration systems use multiple filters to remove pretty much anything you would want to be removed from your water, including chemicals like lead, chromium, copper, and chloride, bacteria, viruses, and heavy metals. When shopping, be sure to check the complete list of contaminants that each system removes.

What water pressure do I need to use a RO system?

Most RO systems operate from water pressure ranging from 40 to 100 psi. Generally, the reverse osmosis filtration will decrease your actual psi by 50 to 75%. That is why the higher the psi ratings, the better.

Filter pitcher or faucet filter: which is better?

There isn’t an answer as to whether a water filtration pitcher RO system is better than a faucet filter or vice versa. The question is, which one better suits your lifestyle? A reverse osmosis filter pitcher is portable, so you can take them when you travel or to the office.

The downside is you have to keep filling the reverse osmosis pitcher. A faucet filter system is convenient because it’s connected to a water supply. However, these are not portable, and you need the countertop space available.

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About Jennifer Hansen
Jennifer Hansen
Jennifer is a clean water enthusiast and the lead editor of Water Filter Spot and created this website several years ago to share information that she's been researching in this industry for over 20 years. Jennifer studied environmental resource science in college and studied Western US water issues, including water policy, water rights, water pollution and environmental concerns.
Jennifer Hansen
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