Best Reverse Osmosis Systems

In a bid to help you pick the right RO unit, we’ve put together this comprehensive review article comprising of some of the top models you can consider when looking for the best reverse osmosis system for your home.

10 Best Reverse Osmosis Systems Review

RO SystemsFiltering CapacityFeatures
iSpring RCC7AK75 GPD6-Stage with Alkaline remineralization
iSpring RCS5T500 GPDTankless with 1:1 waste to a pure water ratio
APEC Water ROES-PH7575 GPD6-stage with Alkaline filter
APEC Water ROES-5050 GPD5 stages of filtration
APEC Water RO-CTOP-PH90 GPD4-stage tankless portable RO system
iSpring RCC7AK-UV75 GPD7 processing stages with UV filter
Home Master TMA-HG150 GPDSuitable for hydroponic gardens or greenhouses
Home Master TMAFC Artesian50 GPD7-stage filtration process
Watts Premier WP53141150 GPD5 stages of filtration
Express Water RO5DX50 GPD5 stages of filtration

iSpring RCC7AK RO System

We recommend iSpring RCC7AK as the best under sink reverse osmosis system.

Key Features:
  • Efficient filtration process ensures crisp, clean, drinking water
  • Restores healthy minerals to the water and improves its pH balance
  • Decent filtration capacity and pure to wastewater ratio

The iSpring RCC7AK is an upgraded version of the RCC7 model with the addition of a nice extra filter. It can filter out all types of contaminants and enrich the water in the same process giving you a healthier, natural-tasting, clean drinking water.

Excellent Filtration Process

The RCC7AK features a multi-layered filtration process designed around 6 very efficient filtration stages specially tailored to progressively remove all types of contaminants and improve the water quality.

The first three stages are pre-filters consisting of a polypropylene sediment filter in the 1st stage, a GAC filter in the 2nd stage, and a carbon block filter in the 3rd stage.

These three filters trap all the sediments and particles that are larger than 5 microns and more importantly remove chlorine, chloramines, and other chemicals present in the water.

The fourth stage where the magic happens sits a quality RO membrane which eliminates all the remaining contaminants down to 0.0001 microns leaving behind only pure water.

A fine GAC filter takes the fifth stage and where the water from the RO tank is further polished to remove any residual contaminants from the tank.

Restoration of Lost Minerals

After going through the initial 5-stage RO filtration process, the RCC7AK includes a 6th stage which consists of an alkaline remineralization filter.

The standard 5 stages produce clean, pure water with all the contaminants removed as well as the few helpful minerals present in the water.

This 6th stage is a big plus as the alkaline filter restores the healthy minerals lost due to the RO process. The AK filter features red mineral stones which add back calcium and other essential minerals such as magnesium and potassium.

The filter also has a calcite portion that helps raise the pH levels of the RO water hence creating a much natural alkaline balance in the water.

Therefore, you not only get the benefit of drinking clean, purified water but you are also assured of getting some healthy minerals as well and a better, more natural taste.

RO water is so pure and as such it often tastes unnatural, but with this alkaline filter in place, your water will certainly taste much better.

Furthermore, the filter is made up of only natural mineral stones that serve as the filtration media hence your body will have no problem absorbing the restored minerals directly.

Filtration Capacity

The filtration capacity of the RO membrane of this iSpring RCC7AK model is also quite decent for an under-sink residential RO system.

It’s capable of producing up to 75 gallons of filtered water a day which is sufficient to handle the water needs of small to medium-sized families whether it’s drinking or cooking.

Moreover, the system is relatively efficient as for each gallon of pure water produced, it wastes only 2 gallons which is really a mean feat for most filtration systems.

Installation and Maintenance

Featuring quick fittings, a cabinet fitted bracket, and a clear, well-organized manual and videos, installing the RCC7AK is quite easy, especially if you have some little DIY skills.

All the parts you need including the pressurized tank, faucet, drain saddle, feed water adapter, tank valve, and tubings are provided alongside the filters, membrane, and the RO frame itself.

The system will easily fit under any standard kitchen sink and the overall construction is quite solid. The filters are durable too with the first three pre-filters requiring replacing just twice a year and the two post-filters requiring changing once a year.

The membrane will last 2 to 3 years based on the quality of your source water. Noise won’t also be a major problem like in other systems. The unit runs smoothly producing the least sound possible. 

All in all, the iSpring RCC7AK is a well-designed RO system with an effective 6-stage filtration process that eliminates all kinds of contaminants from the water and replenishes it with essential, natural minerals.

It’s definitely a win-win investment for anyone looking for an affordable system that can deliver a more natural tasting and healthier filtered water.


  • Efficient filtration process ensures crisp, clean, drinking water
  • Restores healthy minerals to the water and improves its pH balance
  • Decent filtration capacity and pure to wastewater ratio
  • Durable stainless steel construction 
  • Easy installation with a convenient noise-free operation
  • Backed by one year warranty plus a one-year money-back guarantee


  • That automatic shut off valve seems a bit flimsy
  • May need some DIY skills for easy installation

iSpring RCS5T Tankless

We recommend iSpring RCS5T as the best whole house reverse osmosis system for well water.

iSpring RCS5T is designed purposely for those looking for a system that can supply purified drinking water on demand.

It’s a high-capacity tankless RO water filter system with an on-demand output ability which makes it a great choice for large families, small restaurants, coffee shops, and offices. 

Filtration Process

The RCS5T offers 5 stages of filtration with the first stage being a polypropylene sediment filter which removes debris down to 5 microns. It has see-through housing that allows you to easily see if it’s blocked and requires replacement.

The next cartridge is a granular activated carbon (GAC) filter which traps chlorine particles, chloramines, and other pollutants like phenol and mineral oils.

The third stage consists of a carbon block filter which further removes all residual chlorine, tastes, odors as well as chloramines and microorganisms.

In the fourth stage is one high-quality dual-flow RO membrane that removes contaminants down to 0.0001 microns which virtually eliminates 99% of all contaminants and pollutants common in the city or well water.

The last stage in the system is the post-carbon filter which takes care of any residual chlorine, chemicals, or taste impurities and odors from the RO tank.

Tankless Operation

While it has a very effective RO filtration process, what makes this iSpring RCS5T system stand out is that it’s equipped with a dual-flow membrane and booster pump, a combination that allows it to produce purified water on demand without requiring a storage tank.

This ability to work without the need for a tank makes the RCS5T an ideal choice for small commercial purposes as well as for households as it’s a great space-saving option.

In addition, the pre-installed booster pump does well to raise the water pressure going into the RO system which helps boost its performance and production rate.

The system can work with feed water pressure that’s as low as 25 psi and a maximum psi of 95 to 100, so it will work efficiently and effectively despite the pressure of the source water.

If your feed water pressure is quite low, you will find this booster pump to be a very useful addition plus there’s a nice built-in pressure gauge to allow you easily monitor the pressure.

Filtration Capacity

With a capacity to produce 500 gallons of filtered water per day under ideal conditions, this iSpring RCS5T model is more than capable of meeting the daily demands of most large households and small offices with around 10 to 20 people.

The capacity is large enough to allow you even use the system for small commercial purposes like in a small restaurant, coffee shop, or store and you will hardly notice any minor variations in the water production.

The best part is that you can pair the system with a pressurized storage tank if you desire to have reserve capacity for a steady and continuous supply.

A storage tank will be essential in case of very high usage situations, especially for commercial applications. You will need a delivery pump too as the output pressure of the clean water is about 10 to 15 psi on average.

Besides the high capacity, another major highlight of this iSpring RO system is the fact that it offers one of the most balanced pure water to wastewater ratios.

The dual-flow membrane ensures consistent output flow with a 1:1 pure to wastewater ratio which is pretty exceptional for such a high capacity system.

It will produce much less wastewater compared to other similar systems on the market that often have a pure to wastewater ratio of 1:3.

Installation and Maintenance

Installing the RCS5T is a breeze. Like the other iSpring’s systems above, this one is also designed for DIY installation and it comes complete with everything you need to set it up including a free-standing metal frame.

The installation manual is easy to understand and categorically explains every step accompanied by pictures in addition to the direct instructions.

Maintaining the unit is also simple. In fact, the system is designed to flush automatically to ensure the membrane is clean and works efficiently. No need to manually flush it.

All it’s required of you is changing the filter cartridges which is every 6 to 12 months for the carbon filters depending on usage and 2 to 3 years for the membrane. Furthermore, the booster pump produces very minimal noise thereby it won’t cause any disturbances.

The only setback is that it requires a power source for the booster pump which somewhat limits your installation options. Moreover, due to the large capacity, the power levels might be somewhat high, but that’s a tradeoff considering that it delivers a lot of purified water.

Generally, if you own a small restaurant, business or need a reliable tankless RO system for large residential use, then this iSpring RCS5T is a perfect choice. It will certainly not disappoint.


  • Removes up to 99% of contaminants in water
  • High capacity membrane delivers up to 500 GPD
  • Very efficient with 1:1 pure to wastewater ratio
  • Has a booster pump to ensure an optimum feed water pressure
  • Comes with an integrated pressure gauge
  • Installation is very simple and the pump operates quietly
  • Has a 1-year warranty


  • The booster pump may limit your installation options
  • Can lead to high power costs

APEC Essence ROES-PH75

We recommend APEC Water System ROES PH75 as the best RO system with remineralization.

The second spot in our top APEC essence series RO systems is the ROES-PH75 model. This unit is quite identical to the ROES-50 above, but APEC has made two major updates.

The ROES-PH75 comes with an increased water production capacity and an additional remineralization stage which are big improvements that greatly boost its overall performance.

Filtration Process

With the addition of a remineralization filter, the ROES-PH75 offers 6 stages of filtration which includes the same standard 5 stages of the APEC ROES-50.

At the 1st stage is a polypropylene sediment pre-filter which traps all particles larger than 5 microns including silt, dust, rust, and sand particles that might accumulate and clog the other pre-filters and RO membrane.

The 2nd and 3rd stages make use of the super-efficient activated carbon block filters made from coconut shells. These filters together absorb and remove 99.99% of chlorine and chloramines in the water.

They as well remove bad tastes, odors, organic contaminants, VOCs, and other common chemicals like pesticides and herbicides thereby improving the smell and taste of the water.

At the heart of the ROES-PH75 system is the 0.0001-micron TFC RO membrane which filters out 99.9% of all the possible contaminants remaining in the water from total dissolved solids (TDS) to microorganisms and other impurities like lead, arsenic, fluoride, radium, and chromium leaving only pure water to pass through.

The 5th stage applies an activated carbon filter also made from coconut shell which gives the filtered water a finishing touch by removing any residual tastes and odors picked up from the RO tank.

6th Stage – Alkaline Filter

The filtered water from the 5th stage is finally passed through the last stage which comprises of a calcium mineral cartridge that adds high-purity calcium carbonate into the RO water. 

The calcium carbonate effectively neutralizes the acidity of the filtered water and increases the pH level by about 1 to 1.5 resulting in a more balanced alkaline water.

The pH level of the final water will, however, vary based on the initial pH levels of the feed water and its composition. Nonetheless, with the alkaline filter in place, you are guaranteed to get purified alkaline water that tastes much better than plain RO water.

Filtration Capacity and Efficiency

Besides the addition of the alkaline filter, the RO membrane of the ROES-PH75 is an upgrade from that of the ROES-50 as it offers a higher water output.

It can deliver up to 75 gallons per day at 60 psi pressure which is enough to meet the needs of small to large families that desire a high water production rate.

The storage tank can hold 3.2 gallons of water which is a good capacity that will help keep your water supply constant for most parts.

Like the ROES-50, the APEC ROES-PH75 expels 3 gallons of wastewater for each gallon of clean water produced which is not the best ratio out there but it does ensure a high rejection rate and performance compared to systems with a 1:1 or 1:2 ratio.

Installation and Maintenance

When it comes to installing this unit, it’s not overly complicated as it uses quick connect fittings and a clear instruction manual. Therefore, if you are quite a handy person and follow the instruction properly, you will have no difficulty setting it up within a few hours.

Maintaining the system won’t also pose many challenges because you only need to replace the filters which are durable. The stage 1, 2, and 3 filters last 6 to 12 months.

Both the RO membrane and the post-carbon filter can last 2 to 4 years while the sixth filter can be replaced every 4 to 6 years.

All in all, although the wastewater produced is a little on the high end, the APEC ROES-PH75 is a great upgrade from the ROES-50 if you want improved water pH and higher output.


  • Removes all possible contaminants in the water
  • Alkaline filter helps raise the pH level and improves the taste
  • High water production rate at 75 gallons of pure water per day
  • Designed for easy DIY installation and low maintenance
  • Comes with 1-year limited warranty and filters are long-lasting


  • Wastewater to pure water ratio of 3:1 which is just above average
  • Slightly slow filling as it takes about an hour to fill the tank once empty

APEC Essence ROES-50

We recommend APEC ROES-50 Reverse Osmosis System as the best-rated reverse osmosis system that we reviewed.

Despite being a basic model, the ROES-50 is a very efficient unit offering great contaminant rejection rates and reliable performance at a highly competitive price.

Filtration Process

The APEC Essence ROES-50 uses a 5-stage RO filtering process to effectively purify tap water and make it clean and safe for drinking and cooking.

The 1st stage of the system involves a quality 5-micron sediment filter made from polypropylene. This first filter does well to remove sediments and fine particles in the water which include dust, sand, silt, rust, scale, and other large contaminants that are visible to the naked eye.

The sediment filter is followed by APEC’s 5-micron carbon block filter in the 2nd stage which gets rid of chlorine, chloramines, bad taste, odors, colors, VOCs, and other chemicals.

In the 3rd stage is another 10-micron carbon block designed to further remove any residual chlorine, bad taste, odors, and chemicals. 

These double carbon blocks (in the 2nd and 3rd stages) have extremely large surfaces which maximize contact time making the ROES-50 very efficient in attaining the maximum possible chlorine and chemicals removal in tap water.

The 4th stage in the unit features a 0.0001-micron Thin-film Composite (TFC) membrane which has a high contaminant and TDS (total dissolved solids) rejection rate of up to 99%.

This high-quality membrane will remove all kinds of contaminants in the water such as arsenic, chlorine, chromium, bacteria, viruses, lead, toxic fluoride, radium, VOCs, and overall TDS.

The last stage features a coconut shell carbon filter and this performs the final polishing by getting rid of any residual taste and odor from the storage tank to ensure the water delivered to the faucet is totally free of contaminants, odorless, and has a smoother taste.

Filtration Capacity and Efficiency

The ROES-50 system is capable of producing up to 50 gallons of filtered water a day. The rate may, however, vary based on the temperature and pressure of your source water but it will be sufficient for small to medium-sized homes.

Furthermore, the unit comes with a 4-gallon holding tank. It’s slightly larger when compared to similarly priced models and will ensure a steady supply of clean water without long waiting times.

In terms of filtration efficiency, the ROES-50 wastes around 3 gallons of water for every gallon of purified water it produces. This is a little bit above the average 2:1 ratio of most other models but it will not spike your water bills by large a margin.

Installation and Maintenance

Setting up this ROES-50 unit is easy, even without any previous experience. It only requires average DIY skills and everything you need to install it is provided including a detailed instruction manual.

All the quick connect fittings feature stainless steel teeth to guarantee firm grip plus the O-rings are of good quality hence will provide a leak-proof seal.

The first three carbon filters require changing every 6 to 12 months depending on the quality of your source water. The RO membrane can be replaced once after 2 to 3 years while the fifth stage filter can last for up to 2 years.

With its great performance, decent filtration capacity, and durable filters, the APEC Essence ROES-50 is a superb option if you are looking for a standard RO system and the best part is that it’s very affordable.


  • Removes 99% of contaminants in source water
  • Produces 50 gallons of filtered water per day
  • Large holding tank for a steady supply of water
  • Easy to install with leak-free quick connect fittings
  • Long-lasting filters requiring low maintenance
  • Comes with 1-year limited warranty


  • Produces slightly more wastewater
  • Low source water pressure may affect the filtration capacity

APEC RO-OCTOP-PH Countertop RO System

We recommend APEC Water RO-CTOP PH as the best portable (or countertop) Reverse osmosis system.

The RO-OCTOP-PH is without a doubt the best countertop RO system from APEC. It’s a combination of function and portability in one unit that will deliver pure alkaline mineral water.

If you are searching for a countertop system that’s ideal for homes with low pH, then this is an option you should check out.

The model comes in two versions, the RO-CTOP-PH and the RO-CTOP-PHC. The difference between the two is that the cartridges of RO-CTOP-PHC come with casing while the ones in the RO-CTOP-PH are exposed. Our review below is based on the RO-CTOP-PH.

Filtration Process

The RO-CTOP-PH is a 4-stage system featuring two prefilters, an RO membrane, and an alkaline filter.

The 1st stage is made up of a polypropylene sediment filter which removes dirt, sand, rust, and all larger impurities in the water down to 5 microns.

The 2nd stage is equipped with an efficient coconut shell carbon filter that captures chlorine, chloramines, VOCs, and common chemicals that cause unpleasant taste and odor. It also helps to further trap smaller sediments and remove color and cloudiness. 

In the 3rd stage, we have the 0.0001-micron FILMTEC RO membrane where up to 99% of all TDS and remaining contaminants like fluoride, bacteria, viruses, and heavy metals such as lead and arsenic are totally removed from the water. 

The 4th and last stage in the RO-CTOP-PH system is a food-grade calcite mineral cartridge. This filter adds calcium carbonate into the water which introduces calcium minerals that neutralize the acidity of the RO water and raise its pH level. The resulting water has a more balanced alkalinity and a much pleasant, natural taste.

Filtration Capacity

Despite being a compact, countertop RO system, this APEC RO-CTOP-PH model offers a high water output. It’s capable of generating 90 gallons of pure water per day making it one of the best countertop RO systems for those with high water consumption.

Installation and Maintenance

Considering that it’s designed to stay on a countertop, the installation of the RO-CTOP-PH is a simple, straightforward process. The four filter cartridges come already assembled on a base. You only need to hook it to your faucet and you are done. 

The unit is compact measuring 14 x 6.5 x 6 inches. Therefore it won’t take up much space on your countertop and it weighs just around 10 pounds making it really portable. You can even carry it if you travel a lot and want to keep your water fresh and clean.

The only downside to this particular version is that the filter cartridges are exposed which may not look presentable. However, if you prefer the casing, you can go for the RO-CTOP-PHC which comes with casing.

It’s also worth noting that the unit is compatible with standard faucets only. It will not work with any off-size designer faucet, sprayer, or pull-out taps.


  • Great water filtration performance
  • Alkaline filter helps raise the water pH level
  • Water tastes much better with added calcium minerals
  • Delivers up to 90 gallons of pure water a day
  • Lightweight and very portable
  • Installation is straightforward with little maintenance required
  • Two options to choose from


  • Compatible with only standard faucets
  • Does not feature a storage tank

iSpring RCC7AK-UV

We recommend iSpring RCC7AK-UV as the best reverse osmosis system with UV light.

The iSpring RCC7AK-UV is yet another top-notch model within the iSpring RCC7 series. It’s the variation of the iSpring RCC7AK model offering the same great system that features a remineralization filter but with the addition of a UV light filter. 

Filtration Process

The RCC7AK-UV comes equipped with 7 filtration stages which makes it one of the most comprehensive RO systems from iSpring and one that guarantees the best water quality possible.

The initial 5 stages consist of the standard iSpring’s 3 pre-filters we’ve seen in the other models and they remove all large contaminants down to 5 microns and chemicals particularly chlorine and chloramines.

They are followed by the 0.0001-micron RO membrane that removes up to 99% of all the remaining contaminants. The fifth stage is a finer GAC filter which gives the RO water the final polishing as it leaves the RO tank.

After passing through these initial 5 stages, the RCC7AK-UV model incorporates two more stages comprising of an alkaline remineralization filter and a UV sterilization filter.

Sixth Stage – Alkaline Filter

The 6th stage of the RCC7AK-UV uses an alkaline remineralization filter which is made up of red mineral stones that restore the healthy minerals removed from the RO water by the initial 5 stages. It adds back calcium, magnesium, potassium, and sodium.

The filter also has a calcite portion which helps raise the pH level of the RO water to a natural alkaline balance giving a better and more natural taste. This is essential as the RO filtration process reduces the pH value of the water making it tastes slightly acidic.

Seventh Stage – UV Sterilization Filter

The final stage in this RCC7AK-UV system features a UV sterilization filter that offers an additional level of protection from possible microorganism contamination.

The filter uses a powerful 11W UV lamp which emits UV light as the water passes through it. The UV light kills 99.99% of harmful organic microorganisms that might seep past the RO filters including bacteria, protozoan cysts, and viruses.

To ensure great efficiency, the unit comes with a smart flow sensor switch too which turns off the UV light once the water is not flowing through it thereby saving power. The UV lamp also comes in a protective stainless steel housing to ensure its durability.

Filtration Capacity

The RO membrane of the RCC7AK-UV can deliver a maximum of 75 gallons per day. The capacity might vary though based on your source water pressure and temperature but it’s able to meet the needs of most small to medium-sized families.

The system, however, wastes around 3 gallons of water for every one gallon of clean water it produces. Considering that most of the other iSpring’s model has an average ratio of 2:1, this one will slightly waste more water unless you install a booster pump alongside it.

Installation and Maintenance

As with the other iSpring models on our list, the RCC7AK is not that hard to install yourself if you have basic DIY skills. Everything you need to set it up is provided and the instruction manual is user-friendly with pictures and illustrations that make it easier to understand and follow. The whole unit is compact and will nicely fit under any standard kitchen sink.

Overall, the quality, performance, and features of this RO system are really commendable. By combining both the alkaline and the UV lamp filter means you are always assured of clean, healthy water that has a much better and natural taste throughout.

It’s a system we would highly recommend for anyone wanting a unit that offers more than just the standard RO filtration process.


  • Removes more than 1000 different contaminants
  • Alkaline filter restores healthy minerals and raises pH
  • UV filter to help kill harmful microorganisms in the water
  • Flow sensor switch helps keeps power cost low
  • Up to 75 gallons of clean water output per day
  • Relatively easy to install and operates quietly
  • Comes with a 3-year limited warranty plus a 1-year money-back guarantee


  • Wastes 3 gallons of water per 1 gallon of clean water which slightly above average
  • Low source water pressure may affect production capacity and speed

HydroGardener TMA-HG

We recommend Home Master TMA-HG as the best reverse osmosis system for hydroponics (best RO system for growing)

The HydroGardener TMA-HG is Perfect Water’s solution for gardens and hydroponics. It’s a high-capacity system that’s designed to meet the needs of even the most demanding gardeners with its great water filtration and enhancement capability.

Like the Home Master TMHP Hydroperfection, this unit comes in two versions, the TMA-HG which we’ve reviewed here, and the TMA-HG-PRO which comes with a permeate pump and we will look at it later on.

Filtration Process

The TMA-HG is equipped with 7 stages of filtration which include the Home Master’s Full Contact remineralization technology.

The 1st stage features a 5-micron sediment filter that captures all the large particles and sediments floating on the water.

It’s followed by a carbon filter in the 2nd stage which is made up of a powerful catalytic carbon filtration media.

It effectively removes stubborn and persistent chemical contaminants in the water like chloramine and chlorine. It also helps clear out VOCs, cloudiness, and unpleasant taste and odor.

The 3rd stage features the high capacity RO membrane and it filters the water down to 0.0001 microns thereby stripping the water clean by removing close to 98% of the remaining contaminants which include heavy metals, microorganisms, TDS, chlorine, and other chemical contaminants.

Once the water leaves the membrane, it’s channeled through the artesian filter which forms the first point of the Full Contact remineralization system and 4th and 5th stages of the unit.

The crushed marble media in the filter restore calcium and magnesium minerals into the water making it slightly alkaline.

The carbon media, on the other hand, performs another filtration to clear out any residual chlorine and chemicals before the water finally enters the RO tank.

As the filtered water leaves the tank, the Full Contact technology takes it again through the artesian filter where any taste or odor picked from the RO tank is eliminated by the post-carbon media.

At the same time, the water gets remineralized again with calcium and magnesium ions raising its pH to 6.8 to 7.2 which is an almost neutral pH level. The outcome of these 7 stages of filtration is pure, fresh, and the best possible mineral water for plants, gardens, or hydroponic systems.

Filtration Capacity and Efficiency

One of the key things that make the TMA-HG ideal for gardens is that it features a very high capacity membrane which can produce up to 150 gallons of filtered water per day. That’s amongst the highest production rates out there for a standard-sized RO system like this one.

The unit is pretty efficient too as it only wastes around 2 gallons of water to produce a gallon of purified water. That’s a relatively low ratio considering that the unit does not feature any permeate pump and it will do well to keep your water bills down.

Installation and Maintenance

With the filters fully assembled and already clustered into one RO unit, setting up this Home Master TMA-HG model is a breeze, and anybody with or without basic DIY skills can get it done by just following the installation manual properly.

The filters are equally durable with a modular design which simplify the maintenance process. Both the pre-filters and the artesian filter can go for a year while the RO membrane can serve you for a maximum of 5 years.

Overall, the Home Master TMA-HG is a model we would recommend for anyone with a greenhouse or hydroponic garden and is looking for a reliable RO unit that’s capable of delivering a high amount of purified mineral water regularly without generating a lot of wastewater.


  • Eliminates more than 98% of contaminants in the water
  • Remineralizes the water to raise the pH to a more neutral level
  • Produces up to 150 gallons of pure water in a single day
  • Suitable for hydroponic gardens or greenhouses
  • Low wastewater to pure water ratio of 2:1
  • Installation and maintenance is a breeze
  • Backed by a long 5-year limited warranty


  • Does not feature a permeate pump

Home Master TMAFC Artesian

The TMAFC is a revamp from Home Master’s standard RO systems as it comes with new features that greatly boost its performance.

It’s a quality RO system that effectively filters and remineralizes the source water to produce safe, clean, and better-tasting drinking water. This is our top pick under Home Master’s full contact under sink RO systems.

Filtration Process

The TMAFC is an under sink RO system designed to provide a 7-stage filtration process using only three physical filters and an RO membrane. This is made possible by the full contact technology which has multiple stages that bring about the 7 phases of filtration.

In the 1st stage is a 5-micron quality sediment pre-filter that traps larger particles that are visible to the naked eye. It removes dust, sand, silt, rust and other particles and sediments that are likely to clog the subsequent filter stages.

The 2nd stage consists of a 5-micron granular activated catalytic carbon pre-filter which is a powerful filtration media that removes most of the chemical contaminants like chlorine, pharmaceuticals and VOCs. It clears out cloudiness, unpleasant tastes, odor and even the persistent disinfectant chemicals like chloramines.

In stage 3 sits a 0.0001-micron RO membrane which removes up to 99% of the remaining contaminants in the water.

This very effective membrane will remove fluoride, nitrates, total dissolved solids, cysts, and heavy metals like lead, arsenic, chromium and many other contaminants that pose potential health effects.

Stage 4/5 is a combination of an artesian remineralization medium and a 5-micron coconut shell granular activated carbon post-filter. Here the RO water is further polished by removing any residual chlorine, VOCs and other chemicals.

The refined RO water is then enhanced by the remineralization medium in the same stage. The medium consists of crushed marbles that restore natural calcium and magnesium minerals to the refined RO water thereby raising its alkalinity level before it’s delivered into the holding tank for storage.

From the RO tank, the water goes through a 6th/7th stage where one last filtration and enhancement is done by the carbon post-filter and the artesian remineralization medium.

This last stage clears out any remaining odor and tastes from the RO tank while giving the water one more small addition of calcium and magnesium minerals before it’s delivered to the faucet.

Full Contact Technology

As I mentioned above, the last four stages of the TMAFC are made possible by Home Master’s patented Full Contact Technology. It’s the top feature that sets apart all of Home Master’s RO systems under its full contact series.

This technology allows the system to circulate the purified water through the artesian and carbon filter twice. Once when moving to the RO tank, and once again when moving from the RO tank to the faucet.

This process of remineralizing the water twice is what makes this TMAFC model and the other Home Master full contact systems more robust compared to most of its competitors.

It restores enough minerals to produce clean, pure water with much better-balanced pH levels of around 7.5 to 8.0. In other words, it will certainly give you a cleaner, mineral-rich drinking water that has a fresh natural taste.  

Moreover, the full contact remineralization technology helps prevent the degradation of the RO storage tank.

The filtered water from the RO membrane is usually slightly acidic and when it sits in the storage tank, it attacks the rubber bladder and even dissolves some of it. This degradation often ends up affecting the taste of the water.

Therefore, the inclusion of the remineralization stage between the RO membrane and the tank is a big plus that not only reduces the acidity of the water but also helps prevent the degradation of RO tank and prolongs its lifespan.

Filtration Capacity

The Home Master TMAFC can deliver up to 50 gallons of pure water a day, so it’s much ideal for small or medium-sized households.

The downside though is that the system is not that efficient as the wastewater produced is a little above the usual standard.

Like the Home Master TM model, the unit generates 4 gallons of wastewater for each gallon of clean water produced. This ratio may, however, vary based on the pressure of the source water. The higher it is, the less water wasted.

Installation and Maintenance

When it comes to installation, the TMAFC won’t give you much trouble as it’s tailored for easy DIY installation. Everything you need to set it up is provided including the installation instructions an installation videos are also available to make the process easier.

Same as all the other Home Master RO systems, the filters media and their housings come in one modular assembly hence filter changes are quick and painless. No wrenches required.

The replacement of stage 1, 2 and 4 filters happens once a year while the membrane requires changing after 3 to 4 years.

Generally, despite the high wastewater rate, this Home Master TMAFC model is a great water filtration system that’s worth every penny.

It’s a solid investment especially for anyone looking for a unit that can provide safe, clean water with balanced alkalinity and a pleasant fresh natural taste.


  • Eliminates up to 99% of all contaminants
  • Full contact technology facilitates optimum remineralization
  • Produces purified pH balanced water that tastes fresh and natural
  • An average production rate of 50 GPD suitable for small families
  • Pre-remineralization stage ensures less storage tank degradation
  • Simple and quick to set up and change filters and membrane
  • Backed by a 5-year limited warranty


  • Wastes up to 4 gallons of water to produce a gallon of clean water

Watts Premier WP531411 RO Pure System

Starting our list is one of the top and most affordable under sink RO systems produced by Watts Premier, the WP531411 RO-Pure reverse osmosis system. It’s a standard system with basic RO filtration functions but lives up to Watts’s reputation by being able to eliminate a vast number of different kinds of contaminants for the lowest possible cost.

Filtration Process

The Watts Premier WP531411 system features 4 filtration stages consisting of two pre-filters, an RO membrane and a post-filter.

At the 1st stage, the water goes through a sediment pre-filter which traps particulates that are larger than 5 microns. It removes particles such as dirt, silt, sand and rust that may cause clogging in the later stages.

The 2nd stage of the system features of a 5-micron carbon block pre-filter that helps clear out chlorine, chloramines, most VOCs and any other chemicals that make the water smelly and taste unpleasant.

The 3rd stage is where everything gets going. It consists of a 0.0001-micron RO membrane which effectively filters out all the nasty contaminants from heavy metals like chromium, radium, lead and arsenic to harmful microorganisms like bacteria, virus and cysts. It also removes up to 98% of total dissolved solids and 97% of fluoride.

The final stage is a 5-micron carbon block post-filter which gives the water final polishing after leaving the storage tank. It helps to get rid of residual chlorine or any tastes and odors picked from the storage tank thereby ensuring the water coming out from the faucet is clean and tastes nice.

Filtration Capacity and Efficiency

The WP531411 system doesn’t have a high water output but it can give you a maximum of 50 gallons per day which is pretty the standard capacity of most small under sink RO systems. It should be absolutely sufficient for small to medium-sized households.

In terms of water efficiency, the system wastes around 3 gallons of water to produce one gallon of filtered water. It’s a bit high but just about the average ratio of similar type of RO systems.

The maximum pressure at which it can operate is 100 psi and it requires a minimum pressure of 40 psi to work effectively. If the feed water pressure is below 40 psi, then you will need a booster pump to achieve optimum performance.

Installation and Maintenance

If you are handy with tools, the Watts Premier WP531411 is pretty simple and straightforward to set up. All the necessary components are provided and it requires fewer tube connections, so it’s a matter just following the provided instructions precisely.

Filter and membrane changing is also extremely easy and fast. All it takes is pushing a button where the filter or membrane snaps out and you pull it out and replace it with the new one.

The two pre-filters require changing every 6 months and the post-filter every year while the membrane can last 2 to 5 years based on the quality of the water going into the system.

The other commendable thing about this unit is that it comes with an air gap RO faucet with an indicator that lets you know when it’s time to replace the filters. It turns red when the filters need changing and uses a long-lasting battery that can go up to one year. 

In addition, the unit has a slim, compact design which allows it to fit nicely in any under sink cabinet with minimal space requirements thereby leaving enough room for extra storage.

There are also check valves installed between each cartridge to prevent water and unwanted substances from flowing backwards. Plus the cartridges have double O-rings which as well help prevent leakages.

Generally speaking, there are no major downsides with this unit that we could point out. However, the drain saddle seems finicky. Other than that, everything else is up to standard.

If you working with a tight budget but still seeking a reliable and convenient basic under sink RO system, then this Watts Premier WP531411 model is a suitable pick for you.


  • Removes all kinds of contaminants from the water
  • Has a 50 GPD capacity which is sufficient for small and medium-sized families
  • Installation and filter changing is quick and simple
  • The faucet features an indicator to alert you when filters need changing
  • Slim and compact design that doesn’t take up much space
  • Comes with a 3-year limited warranty


  • The drain saddle is somewhat finicky
  • Wastes 3 gallons of water for each gallon purified water produced

Express Water RO5DX Reverse Osmosis System

The Express RO5DX presents a simple way to filter your tap water at home. It’s a straightforward RO system with a decent filtration performance at an affordable price which makes it an ideal option for those working with a very small budget.

Like most other systems, the RO5DX utilizes a 5-stage filtration process to deliver safe and clean drinking water. The filters from stages one to four remove all possible contaminants in the water source.

The 5th stage consists of a post-activated carbon filter which takes care of odors and residual taste. However, there’s no remineralization filter, so you will have to buy it separately.

The unit can produce around 50 gallons of pure water a day which is standard for most RO units. Combined with the 4-gallon storage tank, you will have sufficient clean drinking water every time.

The best part is that this Express model features an emergency leak stop detector. When the tank is filled, it automatically shuts off the system to stop the water flow into the unit. Hence, there is no danger of water overflowing from the storage tank.

For every gallon of pure water produced, three gallons are wasted, so it’s fairly efficient and will save you some bit of money in the long run.

The unit comes with complete push-in quick-connect fittings that are color-coded to let you know what hose goes where. Plus, the instruction booklet is detailed with diagrams and colored illustrations to aid you.

Therefore, it’s quite easy to install and replace the filters too if you have basic plumbing skills. However, the filters are not long-lasting like in the other units above. The pre-filters need replacement twice a year while the RO membrane and the post-carbon filter need to be replaced once a year.

In general, aside from replacing the filters frequently and the fact that it does not feature a remineralization filter, everything else is perfect and well built.

If you have a tight budget but still want a unit that’s capable of delivering clean drinking water without any issues, then the Express RO5DX might be a good option for you.


  • Impressive 5-stage filtration process
  • Comes with extra filters for easy replacement
  • Automatically shuts off water flow when the storage tank is filled
  • Delivers 0.8 gallons of purified water every minute
  • Easy to set up and use
  • Highly competitive price


  • Does not include a reminieralization filter
  • Filters are replaced frequently compared to other models

Reverse Osmosis System

Reverse osmosis water filter system is a water purification system that uses filtration cartridges which include pre-filter, thin semi-permeable membrane, post-filter, and other accessories to remove undesirable materials and provide clean water for drinking and other purposes.

The process involves using pressure to force the water molecules to flow through the semipermeable membrane while stopping bigger molecules such as bacteria and other impurities.

With the capability of removing up to 99% of all contaminants in the water including dissolved inorganic minerals, reverse osmosis systems offer the most effective water filtration solution available on the market today.

They really do a great job when it comes to purifying water compared to various different types of systems out there.  

Therefore, we’ve put together this comprehensive review article comprising of some of the top models you can consider when looking for the best RO system for your household.

We take a closer look at each unit to give you a complete overview of what makes them stand out and why they are the ideal option compared to the rest. Also included is a buyer’s guide that provides all the necessary information you need to arm yourself with when making your selection.

Filtration Stages Of An RO System

The RO system basically involves 3 main filtration stages, Pre-filter, RO membrane, and Post-filter stage. Here is a closer look at what happens in each of these stages.


The first stage in the RO water filter system is pre-filter and its main purpose is to protect the RO membrane by filtering chlorine and fluoride and removing larger sediment as well as some dissolved solids.

This stage can have several different types of pre-filters ranging from sediment filter, granular activated carbon filter (GAC), and CTO Carbon block filters.

Sediment filters which are often made of Polypropylene are primarily the first line of defense in the RO method. They reduce or completely remove suspended particles such as dirt, rust, organic materials, and sediments from the water down to 5 microns.

The granular activated carbon filter is commonly used to remove natural organic compounds, chemical contaminants, taste, and odor. It also reduces a range of other dissolved contaminants particularly chlorine.  

CTO Carbon block filters on the other hand basically have a filtration capability of about 0.5 to 10 microns which makes them quite helpful for removing chlorine, fluorides, taste, and odor, as well as for particulate filtration and insoluble lead reduction.

These pre-filters are essential because they help conserve the RO membrane which can get damaged due to exposure to too much chlorine and fluoride which are often found in municipal water or get clogged by excess sediment.

RO Membrane

The RO membrane is a Thin-film composite membrane (TFC) which is typically a semi-permeable membrane made of two or more layered materials. It’s considered a molecular sieve with pores sized from 0.001 to 0.0001 microns.

The RO membrane is essentially the critical point of the RO system as its extremely tiny pores have a high rejection rate of around 95 to 98%.  

It’s very effective and aids in removing microscopic contaminants such as bacteria, and viruses from the water, as well as dissolved solids like sodium and calcium.

Post Filter(s)

Before the water is ready for use, it goes through a final stage which consists of one or more post-filters that help remove any remaining contaminant that may have slipped past the membrane.

This stage can consist of several other stages including carbon filter, UV light filtration, and PH & Alkaline remineralization, all serving different purposes.

The carbon filter gives the water one last polish by extracting any remaining chlorine, contaminants, odors, or taste residues missed by the membrane and the other pre-filters.

Many RO systems incorporate a further stage of filtration that involves an alkaline or PH filter. The purpose of this stage is to add or restore healthy minerals to the water which may have been removed as a result of the RO filtration process. The filters also help raise the PH of the water to more alkaline levels hence reducing the acidity of the water.

An optional stage in some RO systems is Ultra Violet light filtration which involves the use of UV rays to destroy germs and microbes after the RO stage. This stage helps kill harmful contaminants and bacteria giving you pure and healthy water to drink and use.

Other Basic Components of a RO System

Most RO systems have the same basic components and basically, work the same way. The only difference comes in the quality of the components used and how they look. With that said, the following are the main basic components that make up an RO system and its functions.

Inlet Line and Valve

The inlet line and valve are the first points of the RO process. They are positioned between the RO system and the main water supply to let water gets into the RO system.

These components are simple but crucial.

The Auto Shut Off Valve (SOV)

To help conserve water, the RO system is equipped with an automatic shut-off valve which closes immediately the RO storage tank is full thereby stopping any more water supply through the membrane.

The valve activates when the pressure in the tank is around 2/3 of the feed pressure which helps prevent an over-spill of the water tank.

Once the water is drawn from the faucet, the tank pressure drops and the valve opens to allow the drinking water to pass through the membrane while diverting the contaminated wastewater down the drain.

Check Valve

Also known as a backflow prevention valve, the check valve is positioned just in the RO membrane outlet end and its work is to solely let water out so as to prevent any backflow of the already treated water from the storage tank.

Due to the pressurized RO system, a backward flow could ultimately rupture the RO membrane. Therefore, the check valve ensures water doesn’t flow backward from the system.

Flow Restrictor

The flow restrictor is often located at the RO drain line just after the membrane. Since the RO process operates at very high pressure, the flow restrictor helps maintain the water flow at the correct level required to ensure the system runs smoothly to deliver the highest quality drinking water.

By regulating the water flow, also helps with the system efficiency as excess water doesn’t get washed.

Storage Tank

The RO storage tank holds the purified water once the reverse osmosis process is complete. There are two bladders inside the tank that keep the water pressurized which enables it to exit when the faucet is opened.

The pressure also enables more water to enter the tank only until it is 2/3 of the water inlet pressure. Most standard RO storage tanks have a capacity of 2-4 gallons although the size can range from 2 to 9 gallons.

RO Faucet: Normal/Air Gap

At the end of the RO system is the RO faucet which is normally installed on the kitchen sink. It’s what you use to dispense the purified water. It can be an air gap faucet or a normal faucet, but the most common between the two is the non-air gap models.

Drain Line

The drain line connects the outlet end of the RO membrane housing to a waste pipe and its purpose is to dispose of the wastewater containing all the impurities filtered out by the RO system.

Boost Pump

The RO system is a pressure-driven process and as such its efficiency often relies on the incoming water pressure of the feeding system.

Low inlet pressure will ultimately affect the performance of the system and even compromise the water quality produced if it’s below 45 psi.

A typical RO system operates better at a water pressure of at least 50 psi. Therefore, a boost pump is used to raise the water pressure going into the system when it’s low.

It’s an optional component as the typical city water pressure is usually 60 psi and RO units can run well under this pressure. However, they can are even much better when using the RO booster pump as it can increase the water pressure to 80 psi or even higher.

Reverse Osmosis System Working Process

The RO system is basically reverse osmosis as it uses an external pressure to reverse the natural osmosis process.

By applying external pressure, the system overcomes the natural osmotic pressure thereby forcing the water containing different kinds of dissolved contaminants through a semipermeable membrane.

The membrane only allows the water molecules as well as some other smaller organic molecules to pass through while blocking unwanted molecules and larger particles.

These filtered contaminants are then flushed away thereby leaving clean, fresh drinking water. Typically, the efficiency of any RO system will rely on the water pressure feeding into the system.

Here are the steps.

  1. When the pressurized water first enters the system, it passes through the prefiltration stage which consists of several filters including sediment filter, granular activated carbon filter (GAC) and CTO Carbon block filters. Here, contaminants like sediments, chlorine, dirt, salt, and odor that may damage or clog the RO membrane are removed. 
  2. After pre-filtration, the water is then forced through the RO membrane where the smallest impurities and dissolved particles down to 0.0001 microns are trapped. Only water passes through the membrane at this stage as well as some other very tiny molecules.
  3. After the water exits the membrane, the clean drinking water flows to the RO storage tank where it’s stored until needed while the wastewater containing the removed contaminants get flushed away in the drain line.
  4. Finally, once you open the faucet, the treated water goes through a final postfiltration stage which effectively polishes the water and removes any remaining contaminants that may have slip past the membrane before it enters the faucet for consumption.

What Can An RO System Remove

The RO process can remove a wide range of contaminants from dissolved to suspend ones both organic and inorganic including bacteria and viruses. The RO membrane consists of tiny pores ranging from 0.0001 to 0.001 micron.

Therefore, only water molecules get through while all other contaminants of larger size are collected and flushed away. This includes dirt, dissolved salt, rust, metallic ions, fluoride, chlorine, nitrates and nitrites, cryptosporidium (cyst), bacteria, viruses, and more.

What May Not Be Removed

In theory, some dissolved gases such as carbon dioxide, hydrogen sulfide, and ammonia may permeate the RO membrane without being removed. Other molecules and dissolved organic matter like formaldehyde and methanol may also pass through the membrane.

According to experts some bacteria and viruses may as well get through the RO membrane although it’s quite rare. An RO system fitted with UV light filtration can help remove all living organisms and viruses.

How To Find Your Best Reverse Osmosis System

Reverse osmosis provides a very effective solution to purifying water, but like any other device that you invest your hard-earned cash on, you want to make sure you choose the best system for your home.

With this in mind, here are some key factors that you should consider when purchasing a reverse osmosis system.

best reverse osmosis system review

Source Water

The first thing you want to consider before you proceed to purchase a reverse osmosis system is the type of source water that will go into the system. The two most common water sources are well water and municipally treated water or city water.

The type of water source you use will largely determine the type of unit you choose. If you use city water that has undergone treatment, then the water is relatively free of bacteria and chemicals.

It might also contain some level of inorganic dissolved contaminants, so it’s not completely contaminant-free. In this case, a basic or entry-level reverse osmosis system can do a great job. It will give sufficient filtration to give you fresh, clean water.

If your source is well water, then there’s potential for chemicals and harmful pathogens. Therefore, you will need a unit with a powerful filtration system like the iSpring RCC7AK-UV.

An advanced reverse osmosis system such as the iSpring RCC7AK-UV above is the best because they are able to eliminate all kinds of contaminants in both well water and city water.

Water Demand

The second important thing you should consider is the amount of water you and your family use. You want to make sure you account for everything from drinking to cooking to cleaning to even all your water-using appliances like ice machines and refrigerators.

Most RO systems have a capacity of 50 gallons per day which is enough for a relatively small household. There are other systems that can produce 75 to 90 gallons each day. If you have a large family then a system that delivers 75 gallons or more will be enough.

Filtration Process

The filtration process and number of stages are also important features to consider when shopping for a reverse osmosis system. Most units have around 3 to 5 stages of filtration.

Some more advanced systems like the iSpring RCC7AK-UV feature 6 to 7 stages of filtration. These systems come with additional filters like the remineralization filter and Ultraviolet (UV light) filter.

Systems with 3 to 5 stages are ideal for most applications particularly if you reside in an urban area or your source is municipally treated water. They have all the mandatory filters required to remove all contaminants remaining in the water.

If your source is well water, then the best option would be an advanced RO system with 6 to 7 filtration stages.

Water from wells has high levels of contaminants. They require thorough filtering and an advanced system like iSpring RCC7AK-UV with 7 powerful filters that can effectively clean even the foulest water.

Generally here, the more the number of stages a unit has the better and much effective filtration, purification, and sterilization process the water will undergo. Therefore, make sure you choose a unit that has more than three stages so that you are guaranteed at least some good results.

Water Wastage

The RO system is designed such that there is always wastewater produced. That’s how the technology works. So, if you are sensitive when it comes to your water bills, then this is a factor that you would want to consider too.

How much is too much and how much is reasonable? That’s the question that you need to ask yourself. The most preferred ratio is either 1 gallon of wastewater for every gallon of purified water or 2 gallons of wastewater for each gallon of purified water.

However, most units will produce 3 gallons of wastewater for a gallon of purified water. Basically here, the higher the capacity of the unit the more likely it’s going to produce a lot of wastewater. So, your choice will depend on your water demand but make sure not to pick something that produces more than 4 gallons of waste for a gallon of purified water.

Filter Life and Replacement

The main cost of the RO system is in replacing filters. It’s a long-term running cost and as such you want to ensure you pick a unit whose filters have a longer lifespan. Cheap filters usually require frequent replacements due to their shorter lifespan and as a result, they end up costing more in the long term.

Look for models that have pre-filters that are changed at least once a year. The lifespan of the other filters should range from 2 to 5 years. That way, you will be able to maintain optimum performance and reduce your running cost. 


In general, reverse osmosis systems are one of the best and most effective water purification systems available for households.

When you install an RO system, you can be guaranteed pure, great tasting, healthy drinking water right from your kitchen faucet.

It’s a smart investment that will not only help keep you and your family healthy but will also save you a lot of money in the long run as you will be spending less on bottled water.

The benefits of using a reverse osmosis system to purify your water are countless. They offer one of the most effective and advanced ways of producing clean water. However, to benefit from an RO system you need to pick the best system that will address your particular needs.

The ten options we reviewed above represent some of the top models you would find in the market both in terms of performance and price. The iSpring RCC7AK and the Home Master TMAFC Artesian system in fact offer great value of the money for those looking for quality.

If you live in the suburbs where the source of water is a well or just want a more thorough filtration system, then I would highly recommend the iSpring RCC7AK-UV.

All in all, you should go for a unit that will address all your needs and is suitable for your particular water source. Use the guide above to evaluate every option you consider and in the end, you will be able to pick the right unit for you and your family.