A reverse osmosis system helps to produce clean water in a household. This system eliminates contaminants and pollutants to produce safe water.

Our ultimate guide to the best RO system with buyer guide has all you need to make an informed decision. It’ll save you from getting overwhelmed by the various options and spending a lot of time to choose the right unit for your needs.

You’re going to discover the top brands on the market, how reverse osmosis works, and some frequently asked questions. The guide will also make you understand your water better plus the installation and maintenance of the system.

Our Top Picks For The Best Reverse Osmosis Unit

Home Master TMAFC-ERP Artesian RO System Review

The Home Master TMAFC-ERP makes changing filter elements easier with its modular filter design. Each filter has a unique housing that you change with the filter.

This eliminates chances of debris remaining in the housing. The filter lasts longer and the housing is free from damage.

Changing the filter requires no tools. It’s a matter of pulling out the old filter and pushing the new one in. The filter requires replacement at least annually with instructions from Home Master.

When looking for an efficient system, consider the Home Master TMAFC-ERP works at a ratio of 1:1. This system outputs a gallon of water for each gallon of pure water produced. However, waste water depends on water pressure into the system. High input pressure lowers waste water.

Waste water is created as the system uses pre-filtered water for cleaning the filter membranes. This system has a permeate pump to increase pressure which reduces waste and enhances efficiency.

Why we like it::

  • Outputs 75 gallons of water daily
  • Remineralization of water by Full Contact Technology
  • Better efficiency with less waste
  • Eliminates 98 percent impurities
  • Better filter life
  • DIY installation
  • 4-gallon storage tank
  • 5-year manufacturer’s warranty

What we don’t like:

  • No UV light to kill bacteria
  • A bit pricey


This standard version of the HOME MASTER TMAFC ARTESIAN outputs about 50 gallons daily. It comes with a chrome faucet and faucet adapter. These make drawing water for drinking and cooking easy.

You can just hook this system to your dishwasher using an included fast-flow kit.

This system comes fully assembled for DIY installation. Additionally, there’s a 3/8 inch feed –water adapter with a shut-off valve.

However, there’s a 10 seconds delay at the faucet while using this system. Its storage tank is designed to minimize delay but it’s not very effective. Ensure that the system fits the space under your sink.

APEC ROES-50 Top Tier 5-Stage Ultra Safe RO System

The APEC ROES-50 Top Tier 5-Stage system operates at 3:1. It produces 3 gallons of waste water to produce a gallon of pure water. This makes this system have above-average efficiency.

The system uses 5 very efficient filters to produce pure water with about 99 percent contaminants removed. So, it performs well for tap and well water

New filters are cheaper by a full set and easy to change. The fourth filter is an RO membrane that only particles not bigger than .0001 microns can remain in the water. This supports the elimination of most contaminants including hormones and pharmaceutical drugs.

With NSF and FDA certified JG Food grade tubes, water from this system is safe and free from impurities. The quality manufacturing and operating standards of the APEC ROES-50 Top Tier 5-Stage system guarantee refreshing and crisp water with a natural taste free from a plastic aftertaste.

Why we like it:

  • Eliminates 99 percent contaminants
  • Long-lasting filters for unlimited clean water
  • Comes with an extra set of filters
  • 30-day full money back guarantee
  • 1-year satisfaction guarantee
  • No electricity required
  • Free technical support

What we don’t like:

  • Requires water pressure for better filtration
  • Empty tank takes longer to fill
  • Faucet could do better

iSPRING RCC7AK RO System Review

The iSpring RCC7AK is a 6-stage well-priced alkaline filter system. It outputs 75 gallons daily and comes with lifetime customer support from certified professionals.

The DIY installation of the iSpring RCC7AK takes a few hours and with ready technical support just a phone call away. It fits under any standard kitchen sink and comes with all parts included with a manual and videos.

A 5-stage unit has a membrane that removes harmful pollutants and some useful minerals. So, the output has a pH below 7.0.

However, the iSpring RCC7AK has an extra 6th stage where alkaline remineralization happens. This ensures restoration of healthy minerals and balanced alkalinity for the water to have a natural taste.

This system has premium quality components for high reliability and many years of use with low maintenance. It also comes with a clear see-through 1st stage housing to make inspecting the filter a breeze.

Why we like it:

  • Pocket-friendly price
  • Cheaper filters
  • Water has a better taste
  • Ideal for big households
  • Low pure water to waste water ratio
  • Larger RO membrane for faster water production

What we don’t like:

  • Leaky supply valve
  • All lost minerals not replenished
  • Some technical skills required for installation

APEC ROES-PH75 Top Tier Alkaline Mineral RO System Review

Another system on our list with 6-stage filtration, the APEC ROES-PH75 is of high-quality parts. It’s virtually impossible for any contaminant to escape this rigorous filtration system. This guarantees cleaner and safer water for drinking and cooking.

It comes with long lasting filters to function longer than expected. Additionally, the filters offer 75 gallons of water daily.

The 6th stage of the APEC ROES-PH75 performs remineralization for better tasting water. This system replenishes calcium to enhance alkalinity for the water to taste better.

The APEC ROES-PH75 system has a 100 percent lead-free faucet and FDA Certified JG Food Grade tubes and parts. These ensure safe water free from contamination.

It’s high quality connect fittings are leak-proof. These require no extra lock clips for sealing leaks. There’s no need to invest in a water leak detector.

Why we like it:

  • System easy to maintain
  • Storage tank fills up much faster
  • Automatic shut off lessens waste water
  • Intense filtration ensures safer water
  • Long lasting quality filters
  • Straightforward installation instructions

What we don’t like:

  • Installation requires some patience

iSpring RCS5T Commercial Grade RO System Review

The iSpring RCS5T beats other systems for minimal noise. There’s sufficient pressure to the water on the RO membrane to output 400 gallons daily. Regardless of water pressure, this system works efficiently and effectively.

The iSpring RCS5T comes with a patented dual-flow membrane. This receives water from all sides of the membrane housing fueled by a high power booster pump. The high pressure to the membrane leads to faster production and less waste water for an exceptional 1:1 production ratio.

This reverse osmosis unit is tankless but is efficient in offering water for an aquarium or hydroponic garden. Its filters eliminate all particles that might wear out the system and shorten its lifespan. The filters require close monitoring for quality performance.

Installation is a breeze with a straightforward manual with pictures. The system comes in a package that includes faucets, filters, booster pump, tubing, fittings, water supply connector, and drain saddle.

Why we like it:

  • Pocket-friendly price
  • Noise-free operation
  • Comes with delivery pump
  • Easy installation and maintenance
  • Desired pressure for faster flow rate

What we don’t like:

  • No connection to other appliances
  • Doesn’t come with a storage tank

AQUASANA OptimH2O RO Water Filter Review

This is your best bet when looking for a compact under sink system. The AQUASANA OptimH2O has a daily output of 36 gallons and 5 gallons every minute.

The system uses a carbon pre-filter and Claryum post-filter. These remove 95 percent fluoride and mercury, 97 percent chlorine and arsenic, and 99 percent asbestos and lead.

Additionally, this system has a remineralizor that requires replacement annually. This replenishes minerals like potassium and calcium to make the water healthier. This raises the pH from neutral to alkaline.

The AQUASANA OptimH2O has a high output designer metal faucet that outputs 0.8 gallons per minute and is 100 percent lead-free to match any kitchen décor.

The package for this system comes with a set of filters, faucet, 3.2-gallon RO tank, and all necessary accessories required for the installation process.

Why we like it:

  • Easy to install
  • Water with a better taste
  • 2-year manufacturer’s warranty
  • 90 days satisfaction guarantee
  • Lifetime technical support

What we don’t like:

  • Large diameter hole to mount faucet
  • Storage tank replenishment lacking
  • 5:1 waste water ratio too high
  • Gurgling of water is disturbing

WATTS PREMIER RO-Pure 531211 4-Stage RO System Review

The WATTS PREMIER RO-Pure 531211 is a 4-stage system with a 5-micron pre-filter. This filter removes dirt, silt, and rust. Additionally, the filter also eliminates bad odors, chlorine, and bad taste.

With a semi-permeable membrane, this system reduces dissolved solids in water. The system is more suitable for small and medium families for its output of about 50 gallons daily.

The filter for this unit lasts longer, quick and easy to install. Changing the filter is a simple DIY process and requires a simple press of a button.

This filter is fitted with a chrome design air-gap faucet for functionality and aesthetic appeal. There’s also a 3-gallon storage tank.

The WATTS PREMIER RO-Pure 531211 has check valves in the manifold between the cartridges. This lessens the chances of backflow. The system has shut off valves in the filter head to shut off water flow when the cartridge is missing.

Why we like it:

  • Longer lasting filters and membrane
  • Light indicator to tell when to change the filters
  • Included air gap faucet meets local plumbing codes
  • 3-year manufacturer’s warranty

What we don’t like:

  • 3-gallon tank not sufficient at peak demand
  • Faucet installation might require drilling
  • Disturbing noise during water purification
  • Fitting under the sink with garbage disposal requires a drain adapter

Buyers’ Guide to the Best Reverse Osmosis System

Understanding Reverse Osmosis

Reverse Osmosis (RO) is a process where water passes through a porous membrane in opposite direction to that of natural osmosis. This happens because water is subjected to a hydrostatic pressure greater than osmotic pressure.

The RO process requires a semipermeable membrane to remove aesthetic and health-related contaminants. A 5-stage system with pre and post carbon filters is the best home filter system. This desalinates seawater for safe drinking. It requires changing the filter cartridges annually.

After passing through the membrane, the clean water goes into a pressurized storage tank leaving impurities and hazardous material trapped on the other side of the filter. The storage tank connects to a tap or to a sink for convenient use.

Reverse osmosis offers great tasting water. With a reverse osmosis unit, there’s no more chemical filled tap water or expenditure on commercially purified water.  

Why invest in a reverse osmosis unit?

This system helps to remove impurities and other harmful material from water efficiently and cost-effectively.

Installing a reverse osmosis system will give you better water free from substances including:

  • Water hardness
  • Nitrate
  • Sulfate
  • Salts
  • Sodium chloride
  • Uranium
  • Dissolved solids

Your water becomes safer for drinking, cooking, and other household chores.

Why reverse osmosis over other filtration systems?

Osmosis involves a solvent moving from an area of high water potential through a semipermeable membrane to an area of low water potential. The movement equalizes solute concentration on all sides of the membrane to generate osmotic pressure.

Reverse osmosis is when external pressure is applied to reverse the expected flow of solvent. The process works just like other applications incorporating membrane technology.

The diffusive mechanism is the basis for reverse osmosis. Its efficiency of substrate separation depends on concentration level, water flux rate, and pressure. This is what happens during purification of seawater and removal of impurities from water.

Water filter efficiency during reverse osmosis depends on pressure and temperature of water entering the system. This requires membranes with 65 psi of pressure and 77 degrees temperature. Any incremental change in these variables significantly affects the performance of the membrane.

What do pre-membrane filters do?

Pre-filtration is the first stage of the water purification process. Pre-filter membranes are made of carbon or sediment and prepare water to go through the RO filter process.

The pre-filters protect the RO membrane by removing substances that might clog the system.

What is the work of the RO Membrane?

A reverse osmosis membrane is the heart of the system. It’s a semipermeable membrane for removing all remaining impurities and contaminants from pre-filtered water. This makes the water pure and clean for drinking.

The RO membrane is very fine and water molecules pass through it under pressure. This guarantees clean water goes into the storage tank. The contaminants or other impurities remain behind in wastewater for flushing out.

Is the final filter necessary?

A final filter makes the water from the tank undergo a final filtration process before reaching the faucet. The RO faucet is where purified water is accessible from the RO storage tank

This carbon post filter removes any remaining odors from the water before use.

What is remineralization of water?

Remineralization of water is the process of adding back minerals such as calcium and magnesium. These might have been lost during non-selective reverse osmosis.  

What is the work of the permeate pump?

A permeate pump is a non-electrical energy saving device to enhance the efficiency of the reverse osmosis system.

The permeate uses hydraulic energy from the brine water to push additional purified water into the pressure tank. Increase in pressure makes the RO membrane to perform like in an atmospheric tank system.

Using the permeate pump will improve the life of the membrane and your system.

Other benefits of the permeate pump include

  • No need for electrical energy
  • Enhances life of RO membrane
  • Reduced tank fill time by about 65 percent
  • Lowers drain waste water by about 80 percent
  • Improved quality of water with better membrane efficiency

Is UV light necessary on the unit?

Ultraviolet light water purification uses UV light to kill all harmful micro-organisms in the water. Exposing water from your system to UV light will kill the DNA of bacteria to make the water safer.

Municipal water suppliers ensure to treat water before supply to homes. However, there’s a risk of contaminants infiltrating the system to make UV light necessary.

A UV light treatment stage is necessary because:

  • Some water suppliers don’t monitor all contaminants
  • Water main breaks and broken pipes are inevitable
  • Danger of water-borne bacteria

UV light kills 99.9 percent of viruses and bacteria in the water. Having a reverse osmosis unit incorporated with UV light offers peace of mind especially during a boil water advisory.

Reverse Osmosis- Answers to top 5 FAQs

Before you purchase a reverse osmosis system, it pays to know what lies ahead. Below is our compilation of common questions people usually have about these systems. You’ll discover how the units work and the nature of the output water.

How many stages are required before my water is ready?

The reverse osmosis process has 5 stages to revoke up to 99 percent of impurities and hazardous material in the water. These include:

  • Stage One – Sediment filtration
  • Stage Two – Carbon filtration
  • Stage Three – Reverse osmosis membrane
  • Stage Four – Osmotic membrane filtration
  • Stage Five – Inline activated carbon water filter
What does the storage tank do?

A storage tank is a non-pressurized enclosure where water collects after filtration from the system.

The tank has a small diaphragm filled to house pressure through a pump to offer more water to match the various needs. The pump automatically turns on to offer pressurized water when required.

A standard reverse osmosis tank holds about 2 to 4 gallons of water. There’s a bladder inside the tank to keep pressurized when the tank is full. Common RO tanks on the market have a 12-inch diameter and 15-inch height.

How much water is produced?

Expect your system to have a production rate of gallons per day of about 50 percent to 75 percent. It’s true that nobody can use more than 50 gallons of drinking water in a day. However, the 50 gallons per day rating is the speed at which the unit produces water.

At normal water pressure of about 60 psi, the system produces a gallon of water each hour. A system rated to produce 50 gallons daily will offer adequate production for a normal household. You will not realize a higher output than low gallons per day rated system.

Does the system produce waste water?

Reverse osmosis requires water to clean the membrane in the process of purifying the water. Not all filtration systems use the same amount of water.

Some units use more water than the output produced. Such systems shut down when the storage tank is full. It prevents water from continuing to run down the drain.

Some reverse osmosis units have better efficiency and cause low wasted water. However, you can use this water for other purposes to lessen chances of wastage.

A good system has an output ratio of 1:1.

Is the pH of reverse osmosis water more acidic or alkaline?

Water has a pH value of 7, which is neutral. However, reverse osmosis water has a pH value between 5 and 6. This means it’s more acidic.

The system ensures that your water is free from toxic chemicals, insecticides, bacteria, viruses, and heavy metal. The low pH value of RO water is essentially harmless. Drinking pure and clean water regardless of pH level is perfectly safe. The body has a natural way of ensuring a near neutral pH of 7.4.

However, if you prefer water with a more alkaline pH, you can opt for a cartridge that remineralizes, alkalizes, and oxidizes.

Guideline To Understanding Water Properties

How do temperature and pressure affect output?

Feedwater pressure significantly affects water flux and salt rejection by the membranes. The RO process requires applying pressure to water input diverting natural osmotic pressure.  Water that passes through the RO membrane emerges as purified output.

Performance of the RO membrane is very sensitive to temperature changes. High temperature increases water flux because of the higher diffusion rate. Additionally, high temperature increases salt passage by diffusion through the membrane.

Toleration of high temperature by the RO membrane is helpful for stronger and faster cleaning.

What is the quality of water produced?

No system is marketed as producing 100 percent pure water. There’s always a chance of some molecules making their way through the filters. This makes the output very close to pure.

Most systems reduce chloride and sodium at certain levels. Ensure to pick a system with a target reduction level in mind. Complete reduction of chlorine might stress corrosion cracking of some of your equipment.

You can consider a system with a remineralizer to help keep the water pH at an alkaline level. Other systems have fore filters such as a 6th stage to enhance the purity of water.

How long does the RO membrane last?

Hard water causes scales on the RO membrane housing. This slows the flow of purified water because of plugs in the membrane.

The scale abrades the RO membrane to create holes for more contaminants to pass through. Quality carbon pre-filters eliminate any impurities like silt, dirt, and rust that can shorten the lifespan of the membrane.

How to install and maintain your system

Can I handle the installation on my own?

You can purchase a system online and handle the installation on your own. Quality products come with user-friendly manual and videos on YouTube.

However, calling a professional plumber will save you from a lot of trouble. These have the right tools, expertise, and experience to install your system. A professional plumber will also come in handy to fix the issue regarding the system.

The reverse osmosis process operates on normal home water pressure between 40 to 65 psi.

The requirements for a new system include:

  • Reverse osmosis unit
  • Storage tank
  • Installation kit and faucet

What is the best choice among faucet types?

The faucets for reverse osmosis units are either an air gap or non-air gap model. It depends on what the manufacturer offers with their product.

Why choose an air gap faucet

  • Protects system by acting as a physical break
  • Prevents the system from damage caused resulting from clogging
  • Avoids contamination of the RO membrane
  • Compatible with local plumbing codes in many areas
  • It avoids damage and contamination of the membrane

Why choose a non-Air Gap Faucet

  • No gurgling sound
  • One water line so less tubing
  • Friendlier on the pocket
  • Easy to install with fewer connections

General step by step installation process

Step 1: Find a suitable installation location

Step 2: Close the water valve

Step 3: Connect the system to the water line

Step 4: Connect the drain line to the system

Step 5: Attach the faucet in a convenient position

Step 6: Connect the faucet to the unit

Step 7: Place the RO unit under the sink or hung firmly on the wall

Step 8: Hoop up the system after removing any red caps on the tube endings

Step 9: Test run the system to ensure everything is in order

Step 10: Begin using your reverse osmosis unit

Note: Some reverse osmosis units are easy to install. You just need a few DIY skills and experience and your system will be up and run in no time. However, if you’re not sure about what to do, contact an experienced plumber.

What maintenance is required for a reverse osmosis system?

RO systems don’t require much maintenance apart from replacing the RO filters and RO membrane. Replacement is required to maintain the effectiveness of the filtration since scales and sediments wear down the filters and membrane.

You can do this on your own or contact a local water treatment professional.  

Replacing the filters and membrane depends on the type of filter, the quality of your water, and the volume of water you use.

Here is a guide to carry out replacements:

Sediment/carbon pre-filters – Every 6 to 12 months

RO membrane – Every 2 to 3 years

Carbon post-filter – Every 12 months

Here are the 3 top reverse osmosis brands

Reverse osmosis units come in various brands and models. These offer varying levels of efficiency with various filtration stages. Here are our top 3 best brands manufacturers.

Home Master RO water systems

Home Master is a manufacturer of units with an innovative modular design. It’s purification and filtration stages eliminate 99 percent of impurities and contaminants. There’s a remineralizer to replenish minerals.

The units have long-lasting filters that output 3,000 gallons and require a single replacement annually. Reverse osmosis units from Home Master require replacing the filter cartridge and filter housing unlike products from iSpring or APEC.

Replacing the filter cartridge and the housing prevents gunk from building in the filter over time. This leads to safer and healthier water.

APEC RO water systems

APEC manufactures RO units ranging from 50 to 90 gallons per day. The company also has a specialized ROES-PH75 model that outputs 75 gallons and comes with a remineralizer. This offers better tasting water.

There’s also the RO-CTOP, a 4-stage model that has no water storage tank. This makes this unit portable and a breeze to install.

All APEC RO units come with customer satisfaction ratings and certified to eliminate most contaminants.

iSpring RO water systems

iSpring manufactures various models with various features and specifications. The iSpring RCC7AK 6 model that has a remineralization stage to replenish minerals lost during the reverse osmosis process.

The RCC1UP-AK 7 is a 7-stage model that has a UV disinfection stage and remineralization stage, unlike regular 5 stage systems.

And finally…

You have now discovered the top brands and a review of our top picks on the market. Additionally, the guide has offered knowledge about the installation process, answers to FAQs, and water property facts.

Hope these will help you make an informed decision to purchase a reverse osmosis system that suits your needs and budget. Knowing the nature of the filters and filtration stages is key to get more value for your money.

Systems with long-lasting filters are cost effective. Those with a remineralization stage or UV light offer safer, healthier, and better-tasting water.