Best Reverse Osmosis Systems 2021 – Reviews & Buyer?s Guide


Have you known? Water contamination is now one of the most significant issues facing all the world, which causes over a half million diarrhoeal deaths each year – according to the World Health Organization.

So, if you are seeking for the best reverse osmosis system (RO system), then you choose right to protect your sweet family?s health.

Top 8 Best Reverse Osmosis Systems 2021 on The Market

Here I introduce you to top 8 RO water filtration systems for domestic usage. Let?s check them out right now!

1 APEC Top Tier 5-Stage Ultra Safe Reverse Osmosis System?- Our Pick

APEC Top Tier 5-Stage Ultra Safe Reverse Osmosis System Review - AquafilterMag

When choosing products for health, you must think twice. And, the top brands are always recommended.

With the 20-year experience in drinking water filter system, APEC can?t be beaten.

Top Tier 5-Stage Ultra Safe RO is the first on the list with a leak-free structure and high performance to remove almost all contaminants such as chlorine, lead, heavy metals and more.

This RO system builds with dual ultra-large carbon blocks and ??? pipe to maximize the contact time and filtration capacity.

The water filtration process includes 5 stages to ensure that no contaminants are left whether it is the well water or tap water.

There are two levels of water pressure available, 30 gallons per day @60 psi and 50 gallons per day.

What I love is the water quality after going through the RO system. It is unlimited pure and tastes refreshing.

However, the water flow rate is a bit slow so you will have to wait long in case of the empty storage tank. So remember to check the tank regularly.

One more bonus is that the installation is almost DIY even if you have no experience with pumping before.

All components are perfectly fit to set you free from a water leak and extra lock clips. The maintenance is also a peace of mind. If you are not a kind of mending things, you can register the 2-year extended warranty.


  • High capacity
  • The leak-free and functional design
  • The natural taste of water after filtration
  • Easy to install and maintain


  • Take up more room under the sink
  • Long time to fill in the empty tank


2 APEC Top Tier Alkaline Mineral PH+ 75 GPD 6-Stage Ultra Safe RO System?- Best for Water Taste

APEC Top Tier Alkaline Mineral pH+ 75 GPD 6-Stage Review - AquafilterMag

APEC again. This time, let?s discuss the ESSENCE ROES-PH75.

First, many people are against using the water filtration system saying that the RO system takes all the valuable minerals away along with the contaminants.

It is true, actually. But the APEC ROES-PH75 is worthy since the machine runs through 6 stages to add minerals to the water.

Interesting enough, its US-made calcium carbonate helps increase the PH so that the water tastes more alkaline. Be good for your health and treat your taste at the same time.

If the ratio between wastewater and pure water is 4:1, you can say the RO system is efficient enough. However, ROES-PH75 works even better.

The whole 6-stage process consumes 3 gallons of wastewater to produce one gallon of fresh water. It means you save more money on the water bill.

So, this RO system is on the top efficiency. Other features you should never miss out as well: Free-leak construction; 40-85 psi water pressure; removal of 99.9% contaminants.

Having 6 filters and large storage tank, the whole structure is a bit bulky to handle by one people. So, you should lend a helping help to speed up the installation.

Here come several recommendations when using this RO system. You should change the filters after a while of usage to ensure the water filtration quality.

To be specific, 6 months to 1 year for three first filters; every 2-3 years for the fourth and fifth ones; and every 4-6 years for the sixth filter.


  • Remain minerals in the filtered water
  • Save money thanks to the efficient performance
  • Ensure leak-proof pipes and joints
  • Improve the alkaline water taste


  • Need two people to install all the components. One is alright but takes longer
  • Require more time to fill in than many others


3 Express Water 5-Stage Reverse Osmosis Water Filtration System?- Best for Water Flow Rate

Express Water 5-Stage Reverse Osmosis Water Filtration System Review - AquafilterMag

My friend uses this Express Water RO5DX, and she has strongly recommended it. So, I decide to have a closer look and try. It turns out one of the best reverse osmosis systems.

The water filtration process goes through 5 stages.

The 1st stage is to filter sand, rust, or dirt. The next two stages remove chlorine, organic chemical pollutants using the carbon block and filters.

The 4th stage – the RO Membrane, filters the most dangerous contaminants such as lead, fluoride, or radium. The last stage is to remove possible taste or odor.

The water pressure goes between 40 and 80 psi, meaning the filter can produce about 50 gallons of water per day. It is enough for daily consumption.

To save water and protect your kitchen from water drippings, the manufacturer adds an emergency leak detector to shut off the water flow in case of excess water or unwelcome moisture.

As a result, the Express RO5DX can clear up to 99.9% contaminants and treat your family from ultra-pure water. But at the same time, valuable minerals might be removed away.

The manufacturer recommends swapping the pre-filters twice a year and other filters like RO Membrane, Alkaline, or Post Carbon once a year.


  • High capacity
  • The leak-free and functional design
  • The natural taste of water after filtration
  • Easy to install and maintain


  • Take up more room under the sink
  • Long time to fill in the empty tank


4 iSpring RCC7AK-UV Deluxe Under Sink 7-Stage Reverse Osmosis?- Best in Water Purity

iSpring RCC7AK-UV Deluxe Under Sink 7-Stage Reverse Osmosis - AquafilterMag

This becomes one of the best reverse osmosis systems for many other reasons.

The iSpring RCC7AK-UV has 7 filters – outstanding compare to other system.

It not only guarantees the purity of water by removing over 1000 contaminants but also helps to save natural resources since it wastes only 2 gallons of water to procedure one gallon of germ-free water.

Firstly, the water pressure is 40-75 psi, so do not worry about the clean water shortage.

Secondly, the alkaline PH filter works excellently to remain and balance some ionized minerals in the water and make it tastier and healthier.

Even better, the UVB light included in the system is excellent to kill bacteria and microorganisms, commonly found in well water or that from lakes or streams.

Better save your health, your money, and your Earth.

The lights are auto switched on the running water flow, then switch off right after the flow stop. That way, the filtered water stays pure almost all the time.

However, be careful with the user guide which is like a toilet paper with grammar mistakes and confusing words. Thanks God, you can refer to tutorial videos on Youtube.

About the periodic replacement of filters, you should do it every six months or any longer depending on your water source.


  • Add minerals to the pure water – better for the health
  • Run UVB lights to kill off the most difficult germs
  • Consume less water during the filtration process
  • Easy to install, as long as you follow the right instruction


  • The bad users? manual


5 iSpring RCC7 High Capacity Under Sink 5-Stage Reverse Osmosis?- Best Budget Choice

iSpring RCC7 High Capacity Under Sink 5-Stage Reverse Osmosis - AquafilterMag

7 filters are excellent to guarantee water purity. However, 5 filters are good enough if you live far from pollution sources like industrial factories.

When it comes to the 5-stage RO system, iSpring RCC7 is among best-in-budget choices.

About the efficiency, this water filtration is on the top since the 2.5:1 ratio of wastewater and pure water. It is economical and saves more water on Earth.

It offers 5 layered protection filters to remove 99% contaminants before the water reaches the tank. You should know that iSpring RCC7 is certified ?Gold? Seal in NSF/ANSI standard.

The design is user-friendly. You can tell exactly when to change the first filter since it is seen through. You do not need the threading pipes to ensure the leak-free structure.

Instead, push the tubing a half inch deeper into the connectors. Also, the Europe-designed faucet is a nice bonus which makes a modern addition to most kitchens.

But the user guide is still useless. I really think that the manufacturer needs better marketer.

You can send this RO system back if anything goes wrong about the water quality or the leak-free structure since the 1-year money back guarantee is available at registration. Honestly, hardly anybody feels disappointed at RCC7.


  • Affordable price compared to high-quality features
  • Better efficiency to save more water and money paid for the water bill
  • Nice structure fitting almost every kitchen


  • Again, the installation guide is useless. But, dedicated customer service helps.


6 Home Master TMULTRA-ERP Ultra Undersink RO System?- Best for Water Filtration Efficiency

Home Master TMULTRA-ERP Ultra Undersink RO System - AquafilterMag

Home Master TMULTRA-ERP is the next on the best reverse osmosis system list.

As above. I will get insight into the efficiency, the filter, and the installation.

About the water filtration efficiency, this RO system works exceptionally well to save up to 80% of wastewater and generate up to 50% pure water.

To say, the waste and pure water ratio are 1:1 – Surprisingly. The less wastewater, the better.

The system removes 98% of chemical contaminants and 99% of microorganisms thanks to 6 advanced filters.

Each is specialized in specific functions. For example, the iron pre-filter including advanced redox KDF85 can clear the dissolved iron to protect the RO membrane and purify the water.

The mixed powerful catalytic carbon pre-filter removes poisonous chemicals. And, the UV light chamber is in place to fight microorganisms without changing the taste.

More conveniently, both fittings and tubing are larger than those of traditional RO system so you can expect the flow rate is double fast.

But, honestly, the tubing and plastic clips look cheap and poor-quality, not to mention the components feel messy all together.


  • Affordable price
  • High-efficient in performance to produce more pure water and less wastewater at the same time
  • 6-stage filtration for germ-free water
  • Quick water flow rate


  • Design needs improving


7 Home Master TM Standard Undersink RO System?- The Runner Up in Efficiency

Home Master TM Standard Undersink RO System - AquafilterMag

Home Master TM Standard is the smaller version of the TMULTRA-ERP, but it does not mean the features are not worthy.

I recommend this package if your kitchen is small and the water is not too polluted.

The manufacturer guarantees to remove almost all contaminants such as heavy metals, chloramines, solids, etc. In fact, the filtered water is exceptionally pure.

The ratio between wastewater and pure water is 1:1 or 2:1 – definitely on the top efficiency of the category.

What I like about this RO are its modular filters. The traditional filtration system is often made with canister design.

You usually have to change the filter cartridge which might contaminate the canister making it less durable.

The modular tells a different story. All filters come in the right order from the purchasing, so the installation takes less time and effort. Moreover, when you change the filters, you change the housing as well.

This way is more efficient and straightforward. The installation guide is user-friendly that even those having no experiences with pumping can handle the system themselves.

Just a small complaint – the faucet seems to be made from poor-quality material. You can buy high-quality replacement.


  • High-efficient water filtration
  • Innovative design to protect the system better
  • Easy installation
  • 5-year limited warranty


  • The cheap-look faucet


8 Brondell RO Circle Water Saving Reverse Osmosis Water Filter System?- Most Compact RO System

Brondell RO Circle Water Saving RO Water Filter System - AquafilterMag

Brondell RC100 is the most compact RO system on today?s list. It looks small, fit, and modern.

The most outstanding features of Brondell RC100 is the smart technology to reduce the back pressure using the flexible reservoir and patented valve without requiring electricity or pumps.

This technology not only reduces the wastewater but also fasten the flow rate. The overall performance is 10 times better than most RO systems.

The filtration goes through four stages in which each of the four filters takes responsibility to remove dissolved solids, heavy metals, poisonous chemicals, bad odors and tastes from the water.

Besides the compact design, Brondell RC100 also includes an elegant chrome faucet with LED filter to remind you when to change the filters.

Ensuring filtered water quality is essential. With the twist and seal construction, it takes only some minutes to install the whole package – even if you have not to use the RO system before. Remember to take the drill and adjustable wrench at hand.

For your mind, the filters are sold on the company websites only so when it comes to the periodic change, call the manufacturer to order the placement.


  • Save money on the water bill, and electric bill since this system does not run on electricity
  • Save space and efforts to install thanks to the compact design
  • Provide a fast flow rate and refill rate
  • Easy to install – kind of plug-n?-play


  • Run through four filtration stages only
  • Be hard to buy changeable filters


What Is A Reverse Osmosis Filtering System?Reverse Osmosis system sometime, so you start searching and end up reaching this post.

But do you really understand what the RO is? – If not, keep reading here.

Let?s start with the primary water filtration. This is the process using a filter to block contaminants from penetrating the water physically.

Reverse Osmosis is the ultimate method in water filtration in which water goes through multiple filters, each of which can remove specific types of contaminants.

To do so, the standard reverse osmosis system usually includes a semi-permeable membrane to let the pure water pass through only. Meanwhile, larger molecules such as dissolved metals are removed.

Back then, the RO system was used for industrial processes such as pharmaceutical production, food and beverage processing, or seawater desalination.

Now, the household RO system becomes more and more popular since people pay significant attention to their health.

The benefits are a no-brainer:

Increase Water Purity

As can be seen above, the top RO filtration system guarantees to remove 97-99% of contaminants that possibly cause serious diseases.

Improve The Taste of Water

The contaminated water is terrible in favor, smell and look. Even the tap water under the introduction of fluoride and chlorine has an unpleasant taste and bad odor.

The RO system; hence, filters the tap water fresher. Interesting enough, the top filtration systems like APEC ROES-PH75 even add calcium carbonate so that the water tastes more alkaline.

Save Money

Among various water filtration methods, the reverse osmosis system consumes less electricity. Even better, you won?t need to buy expensive bottled water for daily use.

Having an RO machine in your house save both time and money. It is controversial that using RO wastes a lot of water and ruin the environment.

But you can reuse the wastewater in a bunch of ways: watering the plants; washing your car; floor mopping; the pre-rinsing laundry; etc.

To save more on water consumption, you should choose several systems on the list which the wastewater and pure water ration are only 1:1 or 3:1.

How Does A Reverse Osmosis Filtering System work?

A filtration process through the RO system often includes at least 3 stages: the pre-filter(s); the RO membrane; and the post-filter(s).

Firstly, the water flows into the RO system through Cold Water Line Valve which attaches to the inlet side of the system.

Then, the water reaches the Pre-filter(s) first. There, sized contaminants possible blocking the system. There might be several pre-filters, either sediment filters or carbon filters:

  • The sediment filters are designed to prevent sediment, dirt, or sand silt from penetrating the RO membranes.
  • The carbon filters are in place to get rid of chlorine and contaminants that ruin the durability of the RO membrane. This type of filters also improves water taste and odor.

Next, the water goes into the RO Membrane. This part is the heart of the whole filtration process where almost all contaminants are treated.

After passing through the membrane, the filtered water is stored in a pressurized Storage Tank to prepare for the next stage. This tank is typically 15?? in height and 12?? in diameter so that it can hold 2 to 4 gallons of water.

Also, there are several components built in the RO system to protect the treated water from the possible contaminations.

  • Automatic Shut-Off Valve (SOV) eases the valve automatically in case of the full tank and opens again when the pressure in the tank reduces. This valve impedes the drain flow and does not allow the water to go into the membrane.
  • Check Valve lies at the outlet end of the RO membrane housing to prevent the backward water flow from the tank that can rupture the RO membrane.
  • Drain line from the membrane?s outlet ends to the drain to remove the wastewater filtered out by the RO membrane.
  • Flow Restrictor restricts water going through the membrane to maintain a safe flow rate and the pressure on the inlet side or else all water supply will flow down the drain line.

Once the water flows out of the storage tank, it will approach the Post-filters for the final polishing filtration. This filter is often a carbon filter to discard remaining odors and taste.

Finally, the pure water comes to use through Faucet built-in with the unit. This faucet has different styles, but the non-air gap models are the most common.

Contaminants Removed by Reverse Osmosis Filter

Can the RO system discard all the poisonous substances from the water? – The answer is ?Mostly? – many reverse osmosis filters remove 99% of contaminants.

As mentioned above, the water goes through the multiple-stage process using different filters, each of which takes responsibility to remove specific components, especially the total dissolved solids (TDS).

What is TDS in Water?

The TDS measures the amount of dissolved ions and salts in water after the filtration or evaporation.

The TDS in water often comes from natural sources, industrial waste and sewage, and even the chemicals during the water treatment. The TDS recommended by USRPA should be 500 ppm or below. To say, the lower – the better.

Any higher TDS will more or less cause the water to taste salty, metallic, or bitter, and even unpleasant odors. To be worse, the mineral salts in TDS such as Cadmium, Nitrates, Sulfates, Sodium, Chlorides, Fluoride pose a threat to health.

Read more: 6 Best TDS Meters 2021 ? Why You Need One?

How to check the TDS?

Unfortunately, there are several tools to check the TDS water at home. But here comes the two easiest ways.

Digital TDS Meter

This hand-held tool is to test the quality of the filtered water or tap water.

Just place the meter into the water within 10 seconds, and the measurement sensors work straightforwardly to inform the TDS level.

Filter Paper and a Scale

Instead of TDS meter, you just need some filter paper that you can buy at any supermarket. Prepare at hand a sterilized beaker, the water sample, the filter paper, and the evaporating dish, a stirring stick, a pipette, as well as a scale.

To start, make sure the dish is free from any contaminants. Weigh the dish and save the result as ?A? value. Then, stir the water sample in the sterilized beaker, so the liquid gets evenly distributed.

Next, collect 50 ml of the stirred water in the pipette. Keep stirring the liquid. Extract the water and pass it through the filter paper 3 times.

If there are any particles on the paper, put it to the evaporating dish and wait for it to completely dry. Weight the evaporating dish again. The result is noted as ?B.? TDS level is by subtracting B from A.

Should You Use The RO System to Lower the TDS?

If the TDS is above the average, it does not mean the water is harmful, but you should filter some times more.

In that case, the RO system with multiple filters and the synthetic membrane is the best choice. Only particles smaller than 0.0001 microns to pass through.

How To Install A Reverse Osmosis Water Filter?

The reverse osmosis system is user-friendly to install even if you have no hands-on experience on pumping before. Just follow the manual guide written by the manufacturer.

In fact, the content is confused to follow, you can do some online searches for video tutorials.

And to ensure that all components work properly and leak-free you should consider the following steps:

Step 1: Prepare Tools at Hand

Make sure that all parts of the reverse osmosis filter kit are available Supporting tools such as screwdrivers, adjustable wrench, channel-type pliers, adapter tee, hacksaw, a level, etc. Check the user guide to get prepared

Step 2: Plan Where to Put the System

The most common place to install the housing RO system is under the kitchen sink. You can also refer to the garage or utility room, as long as it can run up to the sink.

Take the measurements of the available space before jumping to purchase. A sink with a garbage disposer is not recommended.

The ideal place must also access the cold water source. In most case, the water source flows into the system using the 1/2-inch cold water supply line.

If the flex line coming down from the faucet is 3/8-inch in wide, then you should use an adapter tee.

Step 3: Start The Installation

Try to stick to every single step of the user guide. From my experience, you should start with the sink spigot. That way, you can get the lines downs before it comes too crowded under the sink.

Mount the spigot to the sink deck. Get the prepared tools involved if necessary. Sometimes, you even need to bore a new hole to the deck so that you can hold the spigot.

Step 4: Position The Tank

Install the tank connector before placing the tank in its position.

Remember to apply the tap of the plumber onto the tank nipple?s threads while connecting the spigot onto the tank without affecting the cross threading. It is better to place the tank below the sink-top spigot.

Step 5: Mount The Filter Assembly

Attach the filters to the wall but remember to leave some spare space so that you can remove the filters more easily for fixture or maintenance.

Setting the assembly on the hanger washers after screwing them on the wall.

Step 6: Attach Other Components

Connect the filter assembly to the water line. If the sink faucet uses flex tubes of a different size, an adapter tee is a solution to consistent the water flow from the source to the filter units.

About another tubing, the installation depends on the manufacturer.

It is common to have four tubes: one to the first canister of the pre-filters; one to connect between the last canister filter to the sink drain, one to the storage tank, and the other to support flows from the reservoir to the spigot.

Step 7: Connect the Drain and Run a Test

If you use a drain adapter tee, please place it against the drain pipe and change the pipe?s height if necessary.

Use nuts and slip washers to connect the tee on the drain pipe before pushing the back drain tee into the adapter tee.

When all components are ready, you can check how it works at ease and try to figure out the loose and leaking.

How To Change And Maintenance RO Systems Filter?

Good news!

A high-quality osmosis system can be used for years as long as you maintain it properly.

The maintenance not only improves the system?s durability but also ensures the quality of water, as well as save money on repair or repurchase.

Honestly, once you use the filtered water, you will not want to get back to ordinary tap water any longer.

The maintenance includes two main tasks: cleaning and changing filters periodically. Filters are there to remove particles from the water, and once a filter is clogged, it no longer works properly.

Tips for Cleaning The Filters and Membranes

  • How often to clean the filters and membrane is based on the water supply source. Some filters are seen through so that you can tell exactly when to do the cleaning
  • It is recommended to clean the system every between three or twelve months
  • Sometimes the water pressure suddenly reduces, or the water tastes strange or odor. It is time to wash the membrane
  • Keep the exteriors clean as well. Many people only focus on the internal components without realizing that the external parts such as the tap or the cover might affect directly to the water output. Hence, wipe the machine and the faucet regularly with a dry or wet cloth.
  • If you are not familiar with the pumping and RO system, you should get professionals to clean the whole system at least once per year. It is affordable to choose a system sanitization service

Change the RO Filters and Membrane Regularly

Periodic cleaning is not enough!

If you fail to replace the filters or membrane when it comes to the time, not only is the system damaged but you also face health problems resulting from the poor-quality water.

I recommend to consult the manual guide or contact the manufacturers whenever you have problems with the maintenance or replacement.

How often you should change the filters and membrane depends on the quality of water supply, the maintenance process, and the technology of the manufacturer. But here comes the recommendations by professionals:

Change Sediment Pre-filter Every 6-12 months

As I shared above, the sediment filters are designed to stain out sediment, dirt, or sand silt from penetrating the RO membranes.

If you do not replace it on time, dirt and silt can clog and foul the RO membranes. That time, the system might come to an end, or the water filtration is not safe enough.

Change Carbon Pre-filters Every 6-12 months

The carbon filters are in place to get rid of chlorine and contaminants that ruin the durability of the RO membrane and improve the water taste and odor.

As similar to the sediment filters, the carbon filters should also be replaced after a half or one year.

Change The RO Membrane at Least Once per year

RO membrane is the heart of the whole filtration process where almost all contaminants are treated.

So if you do not replace it regularly, the whole filtration process becomes in vain. Change it every one to three years.

Change The Post Filter Every 12 months

Post-filters is for final polishing filtration where to discard remaining odors and taste. Do not wait until the water taste is strange.


Reverse Osmosis Systems FAQs

Here come the quick answers for the most frequently asked questions that you might be interested in.

Permeate Pump. Do You Really Need It?

It is not required. But the more, the better.

The permeate pump helps to reduce the back pressure from the storage tank so that the membrane can work full out of the load. As a result, the system produces more clean water, and you can save money in the long term.

What Is An Air Gap Faucet? Is It Any Good?

The air-gap faucet routes up the drain line water from the membrane so that it cannot flow back into the RO units.

On the one hand, this style of faucet protects the system, especially the membrane, from contaminants.

Sometimes, it is required by the manufacturer. However, it might cause the sediment to clog the membrane and make a gurgling sound when the water flows into the storage tank.

Remineralization Filters. Do They Really Help?

Many people want to drink water remaining good minerals. That time, the remineralization filters help to dissolve calcium carbonate which adds essential minerals to improve the taste and to neutralize the pH.

A Single Pass VS. A Double Pass RO System?

I recommend the later. The double-pass RO system keeps the two filtration layers to improve the quality of the permeate since the water in the first pass to become the feed water in the second pass.

Moreover, the 2-pass system discards CO2 from permeate during the injection between the two passes.

A One-Stage and A Two-stage RO System

How many stages of the RO system is among the most frequently asked questions. My answer is that it depends on your water supply. You can test the TDS first and decide whether to use the RO system.

Honestly, the 2-stage is better than the 1-stage system. The water will be filtered more to remove as many contaminants as possible.

Wrapping Up

Do not hesitate anymore since the Reverse Osmosis system is necessary to ensure the health of the company. It is also affordable and easy to install. And, I have given a short cut to the best RO systems and relevant information so that you will not have to search elsewhere.

If you find this post is helpful, feel free to share it with others. And in case of any questions, just leave them right below, and I will try to help you out as soon as possible.