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Top 3 Best Tankless Reverse Osmosis System Reviews 2022

tankless reverse osmosis system reviews


This article will provide you with a detailed comparison of the market’s best tankless reverse osmosis filters. For the ensured health of you and your family, you must have access to clean drinking water. At this point, water filters come in handy.

Reverse osmosis water filtration is the most advanced water filtration technique used worldwide for optimum quality drinking water. RO filters remove out arsenic, chlorine, fluoride, TDS, pharmaceutics, VOCs, and many other substances from the water, making the water healthier to drink.

There are many models and types of reverse osmosis water filtration systems; the choice of the water filter depends on your needs and requirements. There are countertop reverse osmosis water filters, under the sink and tankless reverse osmosis water systems, which you can use for filtering purposes. When you are looking for a small and compact system this article will let you know, 

  • The Best Tankless Reverse Osmosis System Reviews
  • Understanding the concept of reverse osmosis, its benefits, and working
  • Advantages and disadvantages of a Tankless Reverse Osmosis System
  • Buyer’s guide to buying the Best Tankless Reverse Osmosis System.
iSpring RCS5T 500 GPD Tankless Reverse: Grade Commercial
iSpring RCS5T 500 GPD Tankless Reverse: Grade Commercial
  • Brand: ISpring
  • Capacity: 500 Gallons
  • Model Name: 500 GPD Commercial Grade
  • Item Dimensions LxWxH: 14 x 11 x 18 inches
  • Included Components: Housings, filters, parts and tubing, faucet and mounting bracket
  • Purification Method: Reverse Osmosis, Activated Carbon, Carbon block
Waterdrop G3 Tankless Reverse Osmosis Water System
Waterdrop G3 Tankless Reverse Osmosis Water System
  • Brand: Waterdrop
  • Color: Brushed Nickel Based Faucet
  • Power Source: Corded Electric
  • Capacity: 400 Gallons
  • Model Name: WD-G3-W
  • Material: 1. System cover: plastic 2. Faucet: metal 3. RO filter: reverse osmosis membrane 
  • Item Dimensions LxWxH: 18.12 x 5.67 x 17.72 inches
  • Included Components: System cover, Brushed nickel faucet, RO filter, CF filter, CB filter.
  • Lower Temperature Rating: 41 Degrees Fahrenheit
  • Item Weight: 31 Pounds
Frizzlife PD600 Tankless Reverse Osmosis Water System
Frizzlife PD600 Tankless Reverse Osmosis Water System
  • Brand: FRIZZLIFE
  • Capacity: 600 Gallons
  • Material: Stainless steel faucet with brushed nickel finish.
  • Included Components: System cover, brushed nickel faucet.
  • Maximum Flow Rate: 0.41 Gallons Per Minute
  • Purification Method: Reverse Osmosis, Alkaline

Best Tankless Reverse Osmosis Water Filter System

Here is the list of tankless RO systems

  • iSpring RCS5T 500 GPD Tankless Reverse: Grade Commercial
  • Frizzlife PD600 Tankless Reverse Osmosis Water System
  • Waterdrop G3 Tankless Reverse Osmosis Water System

Best Tankless Reverse Osmosis Water Filter System Reviews

Here is some best tankless reverse osmosis water filter system that you can install in your home.

iSpring RCS5T 500 GPD Tankless Reverse Osmosis System: Grade Commercial

iSpring RCS5T reverse osmosis water filtration system is structured to fulfill the filtered water demands of offices, cafeterias, small kitchens, and small-scale restaurants. It is mainly designed for low commercial use and has a compact size to fit about anywhere. For covering high-demand areas, iSpring RCS5T is the best cost-effective solution for reverse osmosis filtering.  

Benefits Of iSpring RCS5T 500 GPD Tankless Reverse Osmosis System: Grade Commercial

Benefits Of iSpring RCS5T 500 GPD Tankless Reverse Osmosis System: Grade Commercial
  • Removes and treats up to 99% of pollutants
  • Has up to 500 GDP flow rate
  • Uses dual reverse osmosis membranes for filtration
  • Cost-effective
  • Best for light commercial use
  • UV light bulb

RCS5T has a complicated installation as it has a structure for high performance.  You may require planning and assistance for the building, but since the system is compact, it can be installed directly at the point of use without occupying much space. Besides that, the user manual is not comprehensive like those of Brondell circle reverse osmosis filters. 

RCS5T has the mechanism to filter and remove up to 99% of the pollutants and 1000 contaminants from your water source. Standard reverse osmosis filtration systems do not remove as many contaminants as this filter does. The reason behind the high elimination of pollutants is that RCS5T employs dual reverse osmosis membranes to ensure the removal of chlorine, fluoride, sulfates, pesticide, herbicides, and arsenic. Other than these chemicals, the RO membranes also remove copper, iron, chromium, radium, and lead.

RCS5T advertises the wastewater ratio of 1:1 due to its patented dual-flow technology. A standard reverse osmosis water filtration system produces 1 gallon of water with 6.7 gallons of wastewater. Water temperature below 77 F might make a higher wastewater ratio. Since the company looks forward to reducing the operation cost, RCS5T has standard-size RO filter cartridges. This reduction of cost might induce a problem during the replacement of the reverse osmosis water filters.


  • 10-15 psi filtered water output
  • Commercial grade quality
  • Compact design
  • low wastewater ratio
  • UV filter to kill bacteria


  • Does not have a storage tank
  • Water pressure decreases at low temperature
  • Complicated user manual

Frizzlife PD600 Tankless Reverse Osmosis Water System

Frizzlife PD600 is one of the smartest and aesthetically pleasing tankless reverse osmosis systems. It has 7-stage reverse osmosis water filtration with a daily output of 600 GDP, including a remineralization filter. This remineralization filter and the tankless system design are what make the Frizzlife PD600 unique and distinct. It has a 7-stage deep filtration system to provide you and your family with fresh and clean reverse osmosis drinking water. Scroll down below to read the Frizzlife PD600 review!

Benefits Of Frizzlife PD600 Tankless Reverse Osmosis Water System

Benefits Of Frizzlife PD600 Tankless Reverse Osmosis Water System
  • 600 GDP flowrate
  • Alkaline remineralization
  • 0.0001-micron precision reverse osmosis membranes
  • Simple and easy installation
  • 7-stage deep filtration
  • Aesthetically pleasing design

Frizzlife PD600 tankless reverse osmosis systems have an effortless and straightforward installation. They do not require a professional or any extra tools for either installation or maintenance. Besides this, the replacement of reverse osmosis membranes and filters does not require turning off the entire system. You can easily replace the filter just by removing it off the faceplate and twisting the filter out.   

Apart from the effortless installation, the reverse osmosis water filters come with an intelligent display that alerts you when to change the filters. The filters only require changing once a year. Other than the automatic alert, the system’s faceplate has an integrated TDS meter that gives you real-time information about your water quality.

Since most tankless reverse osmosis systems do not have remineralization filters, FrizzLife PD600 has got you covered in this area. Reverse osmosis drinking water is slightly acidic as the reverse osmosis filters also remove essential minerals from your water. The 3rd stage of the RO filtration has an alkaline remineralization filter that introduces vital minerals in your water to counteract acidity. These minerals include calcium, potassium, and magnesium. The pH of your final drinking water is 7.5.

In the output produced by reverse osmosis filtration systems, there is wastewater. FrizzLife PD600 has considerably less filtered water to wastewater ratio, 1:5:1. 


  • Smart TDS indicator
  • Quick change filters
  • Good filtered water to wastewater ratio
  • Fast flow rate


  • No brilliant faucet to indicate filter life
  • Expensive

Waterdrop G3 Tankless Reverse Osmosis Water System

Amid efficient reverse osmosis filtration systems, the WaterDrop G3 tankless RO system is the best! This G3 system is NSF certified with DIY installation and will provide you and your family with TDS and Chlorine-free water at a 400GPD flow rate per day. 

Benefits Of Waterdrop G3 Tankless Reverse Osmosis Water System

Benefits Of Waterdrop G3 Tankless Reverse Osmosis Water System
  • NSF, WQA, ANSI standard certified
  • Easy DIY installation
  • Tankless design
  • Removes chlorine, odour and smell, TDS, limescale, and other metals
  • It has a 7-stage deep filtration process

The multi-stage filtration ensures that every contaminant removes itself from the water. The initial filters remove large particles such as dust, silt, and sediments to protect the reverse osmosis membranes. After the water passes through the initial filters, it encounters the DOW reverse osmosis membranes, which work together to eliminate even the most minor impurities. It also contains a coconut shell carbon filter to remove any foul odor and smell. These multiple-stage filters work together to make the WaterDrop reverse osmosis water filtration system the best for your family.

One of the most highlighted features of the G3 system is its easy 30 minutes DIY installation. You do not require any additional tools or a professional to install it. The filter comes with an intelligent designer faucet and smart TDS monitoring panel, displaying the water quality in real-time. Other than the designer faucet, G3 reverse osmosis filtration systems have an overworked reminder accompanying a holiday mode of the filter. 

The holiday mode ensures the reverse osmosis systems automatically flush themselves out if there is no water dispensing in 24hours. Another standout feature of this system is that it does not have a reverse osmosis tank, which saves space undersink and has convenient maintenance access. The tankless feature reduces the growth of bacteria and impurities that can accumulate over time.

The system is NSF/ANSI standard 58 and 372 certified, which means you can be worry-free for any amount of TDS in your water after flushing. Besides this, the flow rate of this RO system is better than any standard reverse osmosis filtration system. You can fill a cup of freshly filtered water from the G3 system in just 12 seconds!


  • Low drain ratio: 1:1
  • No reverse osmosis tank
  • Brilliant faucet and TDS automatic display
  • Automatic flushing
  • Long life of reverse osmosis water filters 
  • Built-in permeate pump
  • Thorough manual


  • No water remineralization
  • Electricity needed to operate
  • Expensive

Tankless Reverse Osmosis Filtration Systems Buyer’s Guide

Buyer’s Guide to consider the best tankless reverse osmosis system before selecting one.

What is reverse osmosis?

Reverse osmosis water filtration is a technique used to filter tap water with the help of a semi-permeable membrane, also known as reverse osmosis membrane. This membrane is the most advanced type of filter used to filter all the contaminants out of the water. Reverse osmosis filtration systems clean the water at a molecular level to become pure and safe for drinking.

Contaminants Removed by Reverse Osmosis

Many manufacturing companies claim that reverse osmosis water filtration systems remove 99.99% of the pollutants from drinking water. Water that comes directly into the taps undergo many chemical processes and carries sediments and impurities along the way before reaching our taps. It is crucial to eliminate any harmful substances that can be a significant hazard to our health.

Reverse osmosis water filtration systems remove:

  • TDS (total dissolved solids)
  • Flouride
  • Chlorine
  • Heavy metals such as lead,
  • Arsenic
  • Cadmium
  • Mercury
  • VOCs
  • Herbicides and pesticides
  • and  many other contaminants

Benefits of Reverse osmosis filters

there are countless benefits of reverse osmosis filters, such as

  • They are easy to install and maintain
  • They are environmental friendly than bottled water
  • Eliminated bad taste and odour
  • It reduces the level of sodium in water
  • It reduces harmful contaminants in a significant amount
  • It can easily fit under the sink.

How does Reverse osmosis filter work?

A reverse osmosis filter system works on five stages which are described below:


Sediment removal filters: before passing through a RO membrane, water must be clean from all the sediments in the water for the accurate filtration process. sediment filters remove sand, dust, and rust 
First carbon filter: the first carbon filter removes harmful substances which cause harm to the semi-permeable RO membrane, such as chlorine and other chemicals. This filter also improves the taste and odor of water plus removes the herbicides and pesticides from water.
Second carbon filter: A second carbon filter is installed to ensure that the contaminants that escaped the first filter can be easily eliminated with the help of a second carbon filter. 

Reverse osmosis membrane

A reverse osmosis membrane is the central functional part of reverse osmosis water filtration systems. It is made to eliminate microscopic organisms up to 0.001 microns. The tiny holes in the membrane allow water molecules to pass through, whereas the larger contaminants stay behind. This technique is effective in removing 99.99% of pollutants in water.

 The removed impurities stay behind, and only clean and filtered water is allowed to pass through. The impure water has a separate pipe, so there is no chance of any contaminants entering your water again.


Remineralization and UV sterilizers are considered post-filters after RO filtration. These filters are optional and depend upon your budget. The remineralizing filter makes the water alkaline in nature and adds the essential minerals back into the water. These minerals include potassium, calcium, and magnesium. Reverse osmosis filtration systems make the water acidic and remove all the vital minerals from water; hence some people use demineralization to solve this problem.

UV sterilizers use UV radiation to kill pathogens and germs from the water. The purpose of installing a UV sterilizer is to prevent bacterial growth in water and keep your drinking water microorganism-free.

What is a Tankless RO Water Filter System?

Tankless reverse osmosis filtration systems are the latest most advanced filters available. These filters are easier to maintain, portable, highly compact, and produce healthy water with an improved taste. They are designed to perform the same task as a traditional reverse osmosis water filter, but the great thing about tankless reverse osmosis systems is that it is compact and takes less space. It does not store water but provides fresh water whenever needed.

These tankless reverse osmosis systems can easily fit beneath the sink and cause readily available water for use. the water purified is fresh and pure with zero contaminants and odor. When you use a standard reverse osmosis water filter, there are many complaints that the tank in the filter takes up too much time to fill and then an extra added time to filter. The tankless RO water filter system is free of this hassle and can provide water instantly.

There are two types of tankless reverse osmosis systems:

  1. Horizontal (sitting) tankless RO systems.
  2. Vertical (standing) tankless RO systems.

Two types of filter cartridges are available for this kind of setting.

  • Front-loaded cartridges mainly used in horizontal RO systems
  • Top loaded filter cartridges found primarily on vertical RO systems

Tankless RO filter systems are mostly known to give unlimited reverse osmosis water with much more speed than other reverse osmosis water filtration systems. Water is directly passed onto the reverse osmosis filters and then flows in the faucet, which means there are more total gallons of filtered water every day.

Advantages of Tankless Reverse Osmosis System

  • It takes up less space and is very compact.
  • The water tastes fresh as it is not stored.
  • It is eco-friendly and does not have wastewater.
  • It also reduces your water bill because of the no storage and no waste features.

Disadvantages of Tankless Reverse Osmosis System

  • It requires an electric system for it to work.
  • We cannot use it in emergencies as it cannot store water for later use.
  • It is slightly expensive than other water filters.

What things to be considered when buying Tankless Reverse Osmosis System

It is crucial to consider the following listed factors to opt for the best tankless reverse osmosis systems. After reading the tankless reverse osmosis system reviews, scroll down for the only buyer’s guide you would ever need!

Water Source

The source of your water is essential knowledge to have when buying a reverse osmosis water filtration system! Water from different sources has different contaminants. For example, water from a well might also have dust and sediment, while the water from the city supply might have other contaminants. It would be best to be aware of the pollutants in your water before choosing a filter system, as different systems eliminate different impurities. 

Brondell Circle reverse osmosis filters eliminate arsenic and barium from your water as well as sediments, while most of the other undersink or countertop reverse osmosis filters do not.


NSF/ANSI certification of the RO systems and component is necessary for their optimum function. Certified reverse osmosis filtration systems have high-grade material which ensures no cross-contamination of your drinking water. Most undersink and countertop reverse osmosis water filters are certified, but you should always visit their website to confirm!

Brondell circle reverse osmosis system and express water reverse osmosis systems are NSF/ANSI standard 58 certified.

Storage Capacity

After reverse osmosis filtering, the filtered water requires storage in a storage tank. Since the reverse osmosis filtration process is considerably slow, it is always safe to have a storage tank for immediate use of water. Some RO filter tanks can store up to 75-gallons of water, but one of the cons of buying a tank-attached countertop reverse osmosis water system is that it occupies a lot of space.

Besides this, you can always opt for tankless RO systems with a high GDP rate, such as express water reverse osmosis systems.

Water Usage

Even the best reverse osmosis filtration systems waste a certain amount of water. Depending on your daily water usage, you should opt for systems with a low wastewater ratio if you live in an area that has water scarcity. Countertop reverse osmosis water filters have a high wastewater ratio as most of these filters do not have attached tanks.

Express water reverse osmosis systems have a standard amount of wastewater to filtered water ratio.

Water Pressure

For an RO system to work, it needs a water pressure of at least 50 pounds per square inch (PSI). In many homes, the water pressure is 30 to 80 PSI. This high pressure is needed to push the water through the various filters and maintain adequate pressure at the tap. The RO booster pump increases the water pressure by up to 80 psi for homes with insufficient force. Even homes that operate on the standard city water pressure of 60 psi can benefit from a pump, as an RO system will run better at 80 psi or higher. If your water pressure is not high, then a tankless RO filter system cannot work efficiently.

Replacement Filters

Most RO systems themselves last 10-15 years, while the filter cartridges last 12-24 months. The replacement of filters also depends on the quality of your tap water. If you have more dirt and impurities in your tap water, you will replace your filters frequently.

The most important thing to consider in replacing your filters is the easy installation. Sometimes replacement filters need to be cleaned thoroughly before putting them back. Some filters are easy to install and swap, which makes the changing of filters much more manageable.


 Even though tankless systems are efficient, they do have their limitations. Mainly, you can’t add UV filters to help against living organisms in water or alkaline filters to help remineralize your water. You’ll need a more extensive system that will use a tank for those types of filters, more than likely.

You will need to add additional alkaline filters that can most likely fit under your sink because tankless RO filters don’t take much room; there is enough space for other additional filters.

UV Sterilizer

A UV sterilizer treats water with germs and micro bacterias with UV light. The wavelength of the UV radiation alters with the DNA of these microorganisms so that they don’t reproduce and make your water impure.

UV disinfection treats water for: 

  • Cryptosporidium
  • Giardia
  • Dysentery bacilli
  • Salmonella
  • Mycobacterium tuberculosis
  • Streptococcus
  • E. coli
  • Hepatitis B
  • Cholera
  • Algae
  • Fungi
  • Some viruses

A tankless reverse osmosis water filter does not come with a UV filter, so installing a UV sterilizer with your water filter is essential. 

Maintenance And Installation

Tankless drinking water filtration systems are easier to install and maintain under your sink because almost everything is contained in one case. There are fewer connections and fewer components.

Also, tankless water filters are simple to replace without shutting off any water lines, using extra tools, or difficult access angles.

The majority of the tankless reverse osmosis systems mentioned have easy twists and replace filters right in front of the case. There will be no leakage of water while you return the filters in the filter system.


The tankless RO system is ideal for getting clean and fresh drinking water with no water pollutants. Reverse osmosis water filters with a tank are most likely to promote bacterial growth and take up a lot of time to fill. Thus it is better to buy any of the tankless reverse osmosis systems that we have recommended.
The bottom line is that tankless reverse osmosis systems are convenient with intelligent design and highly compact features that can easily benefit you and your family. You can also install it under the sink with minimal storage space, which is a bonus feature for you. after buying a tankless reverse osmosis water filter, you are guaranteed to have pure excellent tasting drinking water.

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