Best Reverse Osmosis Water System: Buyers Guide and Review

What is Reverse Osmosis Water System?

 Reverse Osmosis is a water purification method which uses a semipermeable membrane to remove water contaminants such as heavy metal, dead bacteria, dissolved impurities, and large particles. In short, is called RO.

Best Reverse Osmosis comparison table

product name

filtration stage
where to buyadditional features
APEC Top Tier 5-Stage511” x 11” x 15
150Buy from Amazon
APEC Top Tier Supreme Certified High Flow

515 x 7 x 18
190Buy from Amazon
APEC Top Tier Alkaline Mineral pH616 x 5.25 x 17.5
75Buy from AmazonUltra-Safe pH+ Alkaline Re-Mineralizing Calcium Filter
iSpring RCC7517.5 x 14.5 x 5.25
175Buy from Amazon
iSpring RCC7AK
iSpring RCC7AK
618 x 14.5 x 5.25
175Buy from AmazonAlkaline Remineralization Filter
iSpring RCC7AK-UV714.5 x 5.2 x 19.5
175Buy from AmazonAlkaline Remineralization Filter and UV Sterilizer
Express Water 5 Stage516 x 18.25 x 19
150Buy from Amazon4 extra set of replacement filter
Home Master TMAFC-ERP-L7575Buy from Amazonnon-electric permeate pump,catalytic carbon filtration
Global Water RO-505514 x 5 x 16
Buy from Amazon4 extra set of filter
Watts Premier RO-Pure 531411412 x 4 x 12
50Buy from Amazon

The following are some of the contaminants that are removed by Reverse Osmosis:

  • Lead
  • Chlorine
  • Fluoride
  • Pesticides
  • Mercury
  • Arsenic

It is significantly used to purify water from lakes, river, and tap water (public water supply).

How Ro water system works

In Reverse Osmosis, water passes through a semi-permeable membrane which has small pores that only allows clean water to pass through and water containing contaminants is blocked.

There are additional filters (like Sediment filter, Granular Activated Carbon, Micron Carbon Filter, Thin Film Membrane RO Membrane, Inline Granular Carbon Filter and Polishing filters) in the process which remove impurities and then you remain with clean, safe drinking water.

Must watch video how reverse osmosis water system works

What happens to the water that has contaminant?

One of the disadvantages of RO system is the amount of the water wasted in the process. Domestic RO system uses four gallons of contaminated to produce one gallon of filtered water. Three gallons goes to waste, but you can reduce this by adding permeate pump to reduce water wastage. Some system like Home Master TMHP HydroPerfection Under Sink RO System comes with a pump.
The Home Master TMHP HydroPerfection Under Sink RO System reduces the amount of water wastage to one gallon for every gallon produced.
Other systems have advanced technology like Brondell H2O+ Circle Water Saving that reduces amount of two gallons for every of pure water produced
All the same, there is the volume of water that will be wasted that is the concern for every person. In the system, there is a drain pipe or waste pipe. You can connect your waste pipe to the normal faucet or have a collection point and use that water for cleaning, flushing toilet or watering crops.

Stages of RO water system

Most Ro water system involve five stages of filtering

  1. Sediment filter– Removes fine and large particles such as sand, silt, and dirt. It also prevents sediment to go through Reverse Osmosis Membrane which is damaged by sediments
  2. Carbon filter– It consists Activated Carbon, Micron Carbon filter, and Inline Granular Carbon Filter. It helps to remove unnatural tastes, chlorine, odor, suspended particles, organic particles and another chemical that can be found in public water supply.
  3. Reverse Osmosis Membrane– It’s the main component which removes bacteria, viruses, pesticides, chemicals and other dissolved impurities.
  4. Polishing filters – Its final stages or final filter which stabilizes water taste quality and removes any traces of bad odor.

Extra stages

Stage 6: there are important minerals that are removed by the process. At this stage, you can alkalize water or adjust PH using calcium and magnesium. This stage is called Remineralization

Stage 7: use the UV filter to kill microorganism

                     Read more about Reverse Osmosis (

What impurities does Reverse Osmosis system remove?

Reverse osmosis water system operates in five stages and each stage is meant to remove the particular contaminant.

The sediment filter is meant to remove sand, silt, and large particles. Removes impurities 0.001 microns

Carbon filter is best for removing chlorine, bad taste, and odor

Reverse osmosis membrane which is the heart of the system removes wide variety of contaminants such as sodium (salt), sulfate, calcium, potassium, nitrate, iron, zinc, mercury, selenium, phosphate, lead, arsenic, magnesium, nickel, fluoride, manganese, cadmium, barium, cyanide and chloride

Read more the percentage RO membrane removes 

What is Ro water purifier or filter?

Ro water purifier or filter is a water purifier which uses Reverse Osmosis (RO) technology to purify water.

Advantages of Reverse osmosis water system

  • Best solution for treating hard water or salty water
  • RO water purifier removes heavy metals such as lead and mercury which is dangerous to the human being.
  • Removes small and large particles thus gives clean, purified water
  • Removes bad odor from water
  • It’s easier to maintain compared with other purifiers which require being cleaned every month
  • RO water purifier comes in small sizes, so they are best for home use

Disadvantages of Reverse Osmosis water system

  • Requires electricity to operate- It’s not best product in the areas which has the power problem.
  • Water wastage- a lot of water is wasted in the process of purification. Ro water purifier rejects water which contains dissolved impurities, but this water can be used for cleaning
  • Ro water purifier requires high pressure to purify- If water from public supply doesn’t have high-pressure one needs motor to increase pressure
  • Water taste is changed in the process- The process of purification some minerals are removed it alters the taste of water
  • In RO water system there is a high chance that some of the microorganism can pass through RO membrane thus doesn’t kill water-borne diseases that are why it is advised you pass RO water through UV purifier to kill microorganisms.
  • Removes natural minerals such as calcium, magnesium, iron, and sodium which are required in water and are essential to human body. Causing mineral deficiency in the human body.

How much maintenance cost does Ro water system require?

Most Ro water purifiers last for about 10-15 years if the are properly maintained.

Filters and Reverse Osmosis Membrane requires replacement depending on the quality, manufacturer’s instructions, water quality, and usage.

Sediment filters are changed after six months; carbon filter is changed between 6-12months and RO Membrane are changed every 2-3 yearsNote that replacement recommendations are listed under each product according to your manufacturer.

Note that replacement recommendations are listed under each product according to your manufacturer.

There are many different RO water purifiers in the market but most of them differ in various ways such as:

  • Numbers of filtration stages– some purifiers purify water in 3 stages others 5 or 4 stages.
  • Storage and system purification capacity – It’s measured in gallon per day (GPD)
  • Quality of their components
What you need to know before you purchase RO system

Where do you need to set up your RO system?
There are two places you can install your RO system under the sink or at the counter top. If you require to set up under the sink make sure there is enough space the whole system will fit properly
PH level of your water
Test your water and check the level of PH. If your water is acidic buy a system that has an extra stage to balance and stabilize PH level.
Contaminant presence in your water
You need to know which contaminant is the existence in your water so that you can choose the right system to remove them. The system that operates well reduce about 90% of most contaminant found in water

We have researched to find the best RO water purifier in the market and their features.

List of Best Reverse Osmosis Water System in the market

Express Water RO5DX  Reverse Osmosis System 

Best Reverse Osmosis Water System

Check latest price here

It Purifies water in 5-stages which have – Sediment filter, Granular Activated Carbon, Micron Carbon Filter, Thin Film Membrane RO Membrane, Inline Granular Carbon Filter and Polishing filters

  • Sediment filter  which removes inorganic particles- this are large particles and fine particles such as sand, mud, silt, and rust
  • It has GRANULAR ACTIVATED CARBON (GAC) Filters and MICRON CARBON FILTER which removes chlorine, odors, organic chemicals, suspended particles, unnatural taste, dirt and other chemicals in tap water.
  • It has Thin Film Membrane RO Membrane. It’s the main component of any reverse unit which removes viruses, pesticides, bacteria, total dissolved solids and chemical up to 99%
  • It has Inline Granular Carbon Filter and Polishing filters which help in stabilizes water tasting quality and removes traces of bad taste and odor


The system is recommended for water containing maximum TDS of 1000 parts per million (PPM)

System filtration capacity of 50 gallons per day and storage tank capacity of 4 gallons

When it comes to installation the company has made everything easy all connections are labeled and have Color Coordinated caps to match where each hose must be inserted.

In the box, there is extra filter set and leak stopper. The product dimension is 18.2 x 19 x 16 inches

Best for tap water and installed under kitchen sink


With all connection labeled and color coordinated caps to match makes installation easier

APEC Water Systems RO-90- Top Tier

Best Reverse Osmosis Water System

Check latest price here

The system is designed and assembled in the USA

To guarantee safety and your health the system filters water in five stages which is equipped with super capacity filters of (Sediment Filters, Carbon block, Filmtec RO Membrane, refining coconut carbon filter). The filters are NSF certified.

It is also WAQ gold seal certified to remove impurities such as chlorine, heavy metals, fluoride, lead, bacteria, copper, cadmium, radium, barium, viruses and arsenic

APEC water system provides refreshing crisps taste, superior to bottled water and good water ideal for drinking and cooking.

System filtration capacity of 90 gallons per day and has storage tank

For installation, there is step by step online installation video and detailed instruction. The installation is easier just set it and forgets.

The company provides excellent and free technical support for the entire lifetime.

The whole unit size is 15 x 7 x 18 inches which are enough size to fit most kitchen cabinets


The system is capable of producing 90 gallons per day and is 5-stage water filtration system

Easy to follow installation instruction included in the package and online

It provide water with good taste


When installing if you don’t tighten well you may experience leakages.

Home Master TMAFC-ERP-L Artesian Full- Undersink Reverse Osmosis Water Filter System


With 7-stages of purification removes 99% of the contaminant such as chlorine, lead, and chloramines.

Except for filtration, the system has patent full contact technology that adds calcium and magnesium mineral twice during water purification process for greater tasting.

The home master system is designed to solve the problem which traditional system was not able. It uses powerful catalytic carbon filtration to treat stubborn chemical disinfectant chloramines but the traditional system uses an ordinary carbon filter.

The system comes with non-electric permeate pump which improves system efficiency and faster flow rate.

The product uses a modular all in one filter design where the entire filter is disposed, unlike the old system which uses canister filter design where only the filter is changed. This makes Sediment, microorganisms, and biofilm accumulate in the canisters causing canisters to weaken and begin to leak and ultimately fail.

The filters are changed annually and are easy to change with just push in fitting. You don’t require wrenches to change.

You don’t need a plumber to install the package comes with the installation instruction. Also, installation videos and live support is available

It has five-year limited warranty

Additional features Standard Brushed Nickel RO Faucet, Fridge Connection Kit, and Dow Filmtec High Hardness RO membrane

The system has a capacity 75 GPD, 3.2-gallon storage tank and product dimension of 16 x 20 x 12 inches

Where to buy

iSpring RCC7AK – Under-Sink Reverse Osmosis


The iSpring RCC7AK adds a special alkaline re-mineralization filter to remineralize water. This filter is made up of two parts half red mineral stone and half calcite.

The half red mineral stone adds back mineral that was removed during the purification process. Such minerals like ionized calcium, magnesium, sodium, and potassium.

The half calcite neutralizes PH

For quality guarantee, the system filters water into 6 stages, has WQA gold seal, 1-year warranty and lifetime technical support

The system has a size of 18 x 14.5 x 5.25 inches and the holding tank measures 16 x 11 inches which make both tank and body fit nicely at the under- sink cabinet.

In the box is a lead-free solid brass body faucet with a brushed nickel finish which is mounted on the counter as the main output for the RO water.

It has a capacity of 75 GPD and 2.5 gallons holding capacity.

With written installation procedure, video and technical support make the installation process easier.

Where to buy

Global Water RO-505 Reverse Osmosis System

Where to buy

The system filters 1000+ contaminants such as chlorine, fluoride, lead, arsenic, bacteria and others.

With 24 hours technical support and installation kit makes installation steps easy, convenient and secure.

To guarantee quality, health, and pure water the system has 100% lead-free faucet and steel tank complies with NSF or ANSI standard

It filters water in 5 stages and product dimension of 14 x 5 x 16 inches

In the set includes RO system, 2 sediment filters, 2 GAC activated carbon filters, 2 CTO block carbon filters,1 Membrane, 2 Inline filters, Tank, Faucet, Colored Tubing, Installation Kit and Valves. The system provides four extra set of filters.

Watts Premier RO-Pure 531411 4-Stage Reverse Osmosis System

Where to buy

The watt premier is a 4-stage water purification system which removes contaminants such as sediments, chloramines, lead, arsenic, perchlorate, chromium, copper, radium, chlorine, cysts (such as Giardia and Cryptosporidium), bacteria, and viruses.

It has a capacity of 50GPD, product dimension of 12 x 4 x 12 inches and 3-gallon storage tank.

With electronic monitor lets, you know when to change the filter

The system is tested and certified by WQA, NSF/ ANSI

What to consider before purchasing Reverse Osmosis water system
What to consider before purchasing Reverse Osmosis water system

Contaminant it removes

You must know what type of the contaminant the system removes effectively. Buy a system that removes most contaminant found in water. You will not worry the water that you are consuming.

Easy to install, use and maintain

How easy it is to install, use or maintain. Some require professional to install how much will it cost for that. Remember filters needs to be changed every year will it be easier to change and how much will it cost.

Production capacity

The capacity of reverse osmosis system is measured gallons per day (GPD) and it depends on the amount of water you use per day. If your usage is small, a System filtration capacity of 50 gallons per day (GPD) is enough but if your usage is heavier something closer 100 GPD is okay.

How much water waste

One of the disadvantages of RO system is water wastage. You should consider how much water waste will result from the system.

Purification Stages

RO system has seven purification steps. The first three are most important.  The systems you are going to choose to depend on the impurities present in your water source.

Additional features

Some systems come with additional features such as faucet, extra filter, and filter replacement alert

Warranty and customer care service

If the system doesn’t achieve what it should, will the company repair or replace the system?

Where to install the system

Most systems are of the same standard size make sure before you buy you know the dimension of the system and it fits well the place you want to install

choosing the best replacement cartridges, membrane, parts, and accessories that go well with your RO water system read the following:

Best Reverse Osmosis Replacement Filter Cartridge

Best Reverse Osmosis Parts and Accessories

Components of RO system

  • Sediment filter
  • Reverse osmosis membrane
  • Carbon filter
  • Storage tank
  • Post filter
  • Valves
  • Flow restrictor
  • Faucet
  • Drain line

Acquire the best RO water purifier with the help of our guide here

Leave your rating and review in the comment section below