Reverse osmosis filtration systems are the gold standard for protection against the thousands of contaminants that could be lurking in your water, but older models have a reputation for being bulky, expensive and costly to maintain.
Our Top Rated Reverse Osmosis Water Filters
We know that finding the perfect reverse osmosis water system is no picnic. Deciphering technical specifications and sorting the through the hype is exhausting, so relax — we’ve scoured the market to bring you the 7 best models plus a buying guide to help you get the most out of our review.
Let’s get started…
#1. WaterDrop -G3P800 RO System
This is hands down our favorite choice, the WaterDrop RO water filtration system.
Waterdrop took the problems of old and designed a sleek compact design that can be installed in 30 mins or less without the need of a plumber.
Fill a gallon jug in less than 2 minutes…
- High-Flow 800 GPD
- UV filtration
- Installs in 30 minutes or less
- NSF/ANSI 58 certified for TDS Reduction
- 3:1 water waste ratio
- Tankless design for added storage room
Use Coupon code QWL-10OOF
Filtered on the left vs non-filtered on the right
Best For: This is the perfect solution for 99% of families out there when it comes to cost vs value.
Not best for: Those that get their water from a well.
- Waterdrop RO system reduces water waste by 300% over traditional and current units sold online.
- It also has a safe shutdown feature for when you have been running water for longer than 30 mins.
- Filter life is 6 months (sediment/carbon block) & 12 months (Activated carbon) & 24 months (RO Membrane).
- Functionality – This system can be hooked up to your refrigerator with an add-on adapter.
- Minimal waste water – For every 3 gallons of water produced, this system will waste 1 gallon — this is pretty good in comparison to other RO systems.
- Contaminant Removal – The G3P800 is capable of removing over 1000 contaminants that are larger than 0.0001 microns.
- Built-in UV light – If bacteria & viruses worry you, fear not. Waterdrop’s UV filtration will zap 99.9% in its tracks and lasts nearly 50 years.
- Reduces: TDS, limescale, heavy metals, bacteria, viruses, and more than 1,000 other harmful contaminants.
- Filters: To help extend the life of their filters, Waterdrop automatically initiates flushing of the system so you don’t have to worry about it.
- 7-stage filtration process: Removes chlorine, taste and odor, sand, rust, solids, and other impurities.
- Slightly costlier than competitors
- Three filters to change when needed
WaterDrop Product Updates:
- Waterdrop now includes a digital faucet to display TDS and filter life all while your pour a glass of water.
#2. NU Aqua Tankless Reverse osmosis 600GPD System
This is another favorite of ours and not because of the price, but the reliability and convenience of space in under the sink.
With dozens of positive verified reviews, NU aqua gives you 4-stages of water filtration that will remove up 99% of the contaminants we don’t need in our drinking water.
- High-Flow 600 GPD
- Low water pressure booster
- Tool-less quick filter changes
- Filter light change indicator
- 99% of contaminants removed
- 180 satisfaction guarantee
- Compact Tankless design
Best For: This system is cheaper than WaterDrop and provides similar water quality for a compact reverse osmosis system, I think you’ll like it.
- What I love about this system is the fact that I don’t NEED any hand tools to make a filter change – the only thing you have to do is lift the front cover and twist out the old filter to replace –Pretty simple in my book!
- Another positive feature I love is the fact it comes with a water pressure booster – nothing worse than waiting to pour a glass of water especially if you have young kiddos.
- This system has 4-stages of filtration: granular & activated carbon, and a semi-permeable membrane.
- The filters last for 6 months on the PP/CB filter, the GAC will last 12 months and the RO membrane will get you 36 months.
- NU Aqua’s compact tankless filtering capabilites can tackle a broad range of contaminants ranging from: VOC’s, sediment, heavy metals, rust, organic materials, and chlorine.
- The system has a better than average pure water to waste ratio of 2:1 above traditional RO systems.
- NU Aqua comes with a 180 day satisfaction guarantee if you don’t like this system and also comes with a 5-year warranty if you decide to keep it – so you really have nothing to lose .
- However, the Nu-Aqua system is over a 100.00 cheaper and does have a better flow rate but isn’t a space saver like Waterdrop is – you can read our Waterdrop WE-G3 Review here.
- NU Aqua does offer an alkaline filter adapter for those in need.
- Installation can be a pain for some setups
NU Aqua Product Updates:
- NU Aqua now offers a lifetime warranty on this system with a subscription to their filter replacement service. You will save an extra 10% by joining and you don’t have to think about ordering new filters at the last minute –they just show up on time.
#3. iSpring RCS5T Tankless Reverse Osmosis Water Filter — Perfect for Large Families
iSpring’s RCS5T isn’t your typical residential RO water filter — it’s designed to meet the needs of small business including restaurants.
- High-capacity system
- Tankless design saves space
- 0.0001 micron membrane rating
- 1:1 waste to clean water ratio means less water use
Best for: Those looking for a traditional compact reverse osmosis system that’s reliable and affordable.
- Five stages of filtration remove 99-percent of more than a 1000 troublesome contaminants down to 0.0001 microns.
- Ispring also offers up a solid patented dual-flow membrane and powerful booster pump, it provides large volumes of pure water without the need for a storage tank.
- A built-in pressure gauge allows you to monitor the system’s performance without guesswork while the tankless design makes it easy to install in limited space.
- With a 500-gallon per day maximum capacity, this is one of the few true on-demand, whole-home filtration systems that won’t leave a large family without enough filtered water for all of its needs.
- This system can filter both city and well water.
- For well water, the system’s 0.0001 micron rating removes nearly all pathogens.
- The RO membrane should be replaced every 1500 gallons. Pre- and post-filters last six months.
- Most homeowners can install the Ispring RO system with basic know-how in a few hours.
- This unit has exceptional filtration capability, and its size makes it convenient to install.
- Capacity and flow rate are affected by many factors, so practically speaking, you might not get the 500-gallons per day output and flawless flow rate his system can produce under “ideal” condition, but since most filter makers advertise their systems similarly — it’s still comparing apples to apples.
- Limited one-year warranty
- Optional tank required for optimal performance
Ispring RCS5T Product Updates:
- Nothing to report, yet.
#4. Home Master TMHP Undersink Reverse Osmosis Water Filter System
Home Master RO calls the TMHP a “better” filter because it solves a common problem with RO systems — that they remove healthy minerals like calcium and magnesium.
UV light kills pathogens filtration alone could miss
Permeate pump saves water
Easy filter changes
Best for: For anyone on a private well looking for a great performing system that’s reliable and functional.
- All RO systems remove some minerals, but Home Master’s Full Contact remineralization technology adds them back in, and that’s better for your health and the life of your RO system’s storage tank.
- The TMHP will remove all of the contaminants you would expect, and with a UV light, it’s especially effective against pathogens — a must for well water.
- Over-sized fittings and high-flow components mean a faster flow rate, and the integrated permeate pump reduces wastewater production by up to 80-percent.
- I like this system. Despite the tank, it’s compact, and installation is a cinch.
- It looks more complicated than it is when you open the box, but the tubing is all color-coded, and the instructions are well-written.
- As for filtering capability, its micron rating isn’t as high as iSpring’s RCS5T, but it’s close, and with the addition of the UV light, I consider them equal.
- Filters are changed yearly as a set — there’s no complicated maintenance schedule.
- While you won’t get quite as fast a flow at the faucet as with the iSpring, it’s plenty brisk enough for providing drinking and cooking water.
- Filters should be changed every 2,000 gallons or at least once per year.
- The tubing and plastic components are BPA-free.
- Best of all — Home Master backs it with a five-year warranty.
- Storage tank may be a tight fit under sinks with disposals.
Home Master TMHP Product Updates:
- Improved Non-electric permeate pump and reduced TDS Creep
#5. APEC Water Systems ULTIMATE RO-PERM Reverse Osmosis Drinking Water Filter System
Most RO filters need relatively high water pressure to operate, so if your home’s water flow is low, you’ve been out of luck until now.
APEC’s ULTIMATE RO-PERM filtration system comes in two models for different levels of pressure.
- Capable filtration for well or city water
- 36-90 Gallon Per Day (GPD) capacity
- Warranty includes lifetime support
- Dispensing faucet has above average styling
Best For: This is a great system for homes with low water pressure, and for anyone looking to eliminate harmful contaminants efficiently for a great price.
- Five-stage filtration is guaranteed to remove 99-percent of contaminants including arsenic, lead and harmful microorganisms.
- Its super-capacity filters require replacement less often than other brands.
- It comes equipped with a permeate pump that saves energy and helps the storage tank fill faster — so you’ll never run out of clean water.
- It’s assembled in the U.S. A. and comes with a one-year satisfaction guarantee.
- This system will safely reduce TDS.
- The system is pretty simple to install from our own experience.
- The water to waste ratio is 3:1
- This system’s filtration capability is similar to both the iSpring RCS5T and Home Master’s TMHP HydroPerfection.
- Capacity and flow rate are comparable to the TMHP.
- The big advantage of this system is its ability to operate under low pressure. In some parts of the country, that’s gold.
- Permeate pump is noisier than most
- The other difference is the lack of remineralization technology — a disadvantage for health, but an advantage if you don’t have a water softener and want to get rid of at least some minerals.
- For a few dollars more, I prefer the THMP Hydroperfection under most circumstances.
Apec Ultimate Perm RO Product Updates:
- Nothing new, yet.
#6. iSpring RCC7AK-UV Deluxe Under Sink 7-Stage Reverse Osmosis System
iSpring 7-stage put the filtration capability of its whole-home RCS5T system in a smaller point-of-use system.
Seven stages of filtration remove up to 99-percent of unwanted contaminants, and the UV light — one of the strongest in the industry — adds an extra layer of protection again pathogens.
- 75 GPD capacity
- Long-lasting filters
- Remineralization filter
- Straightforward DIY installation
- An alkaline remineralization filter puts the sodium, magnesium, calcium and potassium stripped out of water by the RO membrane back in — restoring a healthy balance.
- Water flow is brisk for a reverse osmosis system, and with no moving parts, it operates silently.
- Long-lasting filters keep the cost of ownership down, and it’s backed by a one-year warranty.
- The first three pre-filters should be changed every six months. The others last a year.
- The UV light is strong — 11 watts instead of the standard six.
- It also turns off via a sensor switch when water isn’t running, extending both the life of the bulb and improving its efficacy.
- The waste water ratio is two gallons of waste water are produced for each gallon filtered.
- iSpring put a lot of thought into this system. From easy homeowner installation to top quality filters, there’s a lot to like here.
- The UV light is exceptionally well-designed. It’s hard to believe most models have bulbs that are on continuously.
- I wish it had a permeate filter for efficiency, but as RO systems go, it’s among the most efficient without one, and it does run quietly — a big plus in some homes.
- Like iSpring’s other products, this filter is so well made I’d be happy to have it my kitchen, but if Home Master can offer a five-year warranty on their TMHP HydroPerfection, I’d like to see iSpring do the same with this system.
- Short one-year warranty
- No permeate pump
Ispring RCC7AK Product Updates:
- Nothing new, yet.
#7. Express Water Alkaline Reverse Osmosis Water Filtration System
Express RO Water says this system delivers the healthiest, freshest-tasting water on Earth — you be the judge.
- Low-cost of ownership
- Easiest installation in it’s class
- Integrated auto shut-off valve
- Makes water alkaline
Best for: Anyone looking for a reverse osmosis system that has long-lasting filters and is capable of removing tough contaminants.
- It starts with five-stages of filtration that remove up to 99.99-percent of chlorine, lead, fluoride, arsenic and more — the highest reduction level in the industry.
- Next, five additional filters add beneficial minerals in much the same way a natural spring does, plus antioxidants and extra oxygen for an energizing experience in every glass.
- Installation couldn’t be easier, and its 50 GPD total output is impressive given its size.
- Long-lasting filters plus a surprisingly low initial price keep the long-term cost of ownership down.
- I don’t know if I need extra oxygen or antioxidants in my water, but for the price of this system, I’m thrilled with its filtration capability.
- It doesn’t come with permeate pump, so the waste to clean water ratio is a little high — three to five gallons — but it runs quietly, and if water costs aren’t going to break the bank, it’s not the biggest deal.
- Hands down, this is the best RO system for anyone worried about do-it-yourself installation — it couldn’t be any easier.
- This system safely removes PFOA’S
- The filters will last 6 months and the RO membrane one year.
- The alkalinity enhancer cartridge can be bypassed.
- It’s also an excellent pick for anyone who wants the security of superb filtration and alkaline water, and with one of the lowest initial prices and low maintenance costs, it’s perfect if you need a high-quality filter on a budget.
- Nothing worth mentioning 🙂
Express Water RO System Product Updates:
- Deluxe chrome faucet is now included
Compare All 7 Reverse Osmosis Systems(Mobile users: Swipe to scroll)
|Compare Brands & Models||#1 WaterDrop G3P800 RO System||#2 NU Aqua RO System 600 GPD||#3 Ispring RCS5T RO System||#4 Home Master TMHP RO||#5 APEC Ultimate RO-PERM||#6 Ispring RCC7AK-UV System||#7 Express Water Alkaline System|
|Water Production||800 GPD||600 GPD||500 GPD||50 GPD||90 GPD||75 GPD||50 GPD|
|Certifications||NSF/ANSI 372, 58 certified||n/a||n/a||NSF 51||n/a||NSF 58 certified||NSF/ANSI Standards 42, 58, 401 and EPA 524.2|
|Warranty||1 year||5 Years||1 year limited||5 Year Limited||1 Year||1 Year limited||1 Year limited|
Buyer’s Guide To Reverse Osmosis Systems
Most reverse osmosis filters reduce or eliminate roughly the same contaminants — it’s the nature of their design. But quality counts, and the features that make some systems more user-friendly and cost-effective than others plays a large part in your long-term satisfaction with the system you choose.
Let’s take the mystery out of how reverse osmosis filters work and take a closer looker at the critical features to look for when comparing models.
What is a reverse osmosis filtering system
Conventional filters use a series of cartridges with different filtration media to remove select contaminants from water. Polypropylene cartridges remove sediment and carbon filters make water taste better. To make water safer, you need more than that.
Reverse osmosis water filters use a special type of high-efficiency, semipermeable membrane as well as conventional filters to capture the maximum number of contaminants and make water taste crisp and clean.
What are the benefits to having a reverse osmosis water filter?
Most reverse osmosis systems remove contaminants larger than 0.001 micron in size or smaller including:
- Bacteria and parasites
- Pesticides and much more
If your family isn’t drinking as much water as they should because they’re worried about what’s in it or you’ve resorted to expensive bottles because of taste, a reverse osmosis system offers peace of mind and is an economical, space-saving and environmentally-friendly alternative.
How does a reverse osmosis water filter work?
Each maker’s design is proprietary, but most perform the same way.
- Pressurized water coming into your home is first treated by a sediment filter that removes sand, silt, rust and other large particles that could clog the RO membrane.
- Next, it passes through a carbon filter that removes minerals and contaminants such as chlorine — a must because high levels of chlorine can ruin better RO membranes.
- After pre-filtration, water is forced through the semipermeable reverse osmosis membrane. Purified water passes through in a holding tank (select systems don’t require a tank), while contaminants are trapped on the other side and flushed away.
- Water then undergoes final post-filtration through a carbon cartridge that removes any trace impurities, making what comes from your tap as pure and delicious as it can be.
What type of reverse osmosis water filter do I need?
Here are few consideration to help you determine the type of system you need:
Whole-home vs under-sink?
For pure water from every tap, choose a whole-home system. To purify drinking and cooking water, a point-of-use system mounted under the sink is small and cost-effective.
Tank vs tankless reverse osmosis?
Tankless systems are smaller, but their capacity is limited. Systems with tanks, however, may be too large to fit under the sink if you have a disposal. Measure carefully before choosing.
Mineral-reducing vs alkalizing?
All RO filters remove minerals. If you want water with the lowest percentage possible of TDS, avoid filters that remineralize water. If you want the health benefits of alkaline water, choose a model that adds minerals back in.
With or without a UV Light?
RO systems remove most pathogens, but some manufacturers are reluctant to claim their systems can make water potable under every circumstance because water quality can vary. If you’re filtering city water, an RO system with a UV light is more than sufficient to safeguard your health. If you’re on a well, a UV light offers an extra measure of protection for nominal cost.
What to look for in a reverse osmosis filter system:
Cellulose Triacetate (CTA) membranes are made with paper by-products bonded to a synthetic layer. A small amount of chlorine in your water is necessary to prevent bacterial growth.
Thin Film Composite (TFC) membranes are fully synthetic and can be irreversibly damaged by chlorine. Systems that use these membranes rely on carbon pre-filters to remove chlorine before water reaches the RO membrane.
So if a chlorine pre-filter is required to use TFC membranes, why are they so popular? Reverse osmosis water filters equipped with TFC membranes are the only ones we recommend because they reject many more contaminants.
Because of the comprehensive filtration RO systems offer, their flow rates are typically lower than non-RO filters. Reported rates are the maximum you can expect under ideal conditions, but because flow is affected by so many factors unrelated to the design of the filter, they alone won’t tell you how brisk it will be. Some design elements enhance flow — like the dual-membrane design on the iSpring RCS5T and the extra large fittings on the Home Master TMHP HydroPerfection — but the flow rate will vary based on water quality, and it’s tough to predict. Flow rates should be considered estimates.
Capacity refers to the maximum number of gallons an RO filter can produce in a day, and that’s important because it needs to make enough to meet your family’s needs. Point-of-use systems are designed to filter water at only one faucet, so their capacity will be lower than whole home systems.
Most families use three gallons or less of water per day for drinking and cooking. For a family of four, that’s 12 gallons. All of the systems on our list well exceed that capacity. The lowest producer — APEC’s ULTIMATE RO-PERM — could make as little as 36 GPD under low-pressure conditions, while the Express Water Alkaline system produces up to 50 GPD. APEC’s Top Tier Supreme 6-Stage Ultra system and iSpring’s RCC7AK-UV Deluxe Under Sink model produce more — 75 to 90 gallons. The FS-TFC Reverse Osmosis Water Filtration System is the winner at 300 GPD.
The only whole-house filter on our list, the iSpring RCS5T, can produce up to 500 GPD — but beware, like flow rates, capacity ratings are reported as maximums. You may get less depending on your water quality.
The costs of maintaining a water filter add up, so when you’re considering the expense, look at the big picture. Individual cartridges vary in price, and each has a finite capacity. To determine your long-term cost of ownership, you’ll need to consider how many filters are in the system and how often they need to be changed. Pre- and post-filters cost less than RO membranes, but they need to replaced more frequently. The best RO system for you will be the one that removes the most target contaminants at the lowest cost.
RO membranes have pores measured in microns — millionths of a meter. The size of the pores determines which contaminants can pass through. Membranes in the systems on our list are rated from 0.001-0.0001 microns and reliably remove all significant pollutants. How much of a difference is there between 0.001 and 0.0001 micron? Not much.
In general, the lower the micron rating, the better, but there’s some disagreement about whether a 0.0001 rating is really accurate because, by most standards, that’s considered waterproof. There is some variation in shape between molecules, so that could be a factor, but short of removing the world tiniest viruses, a 0.001 rating is more than enough to eliminate the pathogens most homeowners should worry about.
What does TDS mean?
Total Dissolved Solids, or TDS, is the amount of dissolved ions in your water. It consists mostly of minerals — some of which are beneficial — but it can also include harmful substances like lead, arsenic and nitrates. Conventional wisdom says that the lower the level of TDS in water, the better. Don’t believe it.
The problem with focusing on TDS is that while it reflects the total number of substances in your water, it tells you little about the type of ions you’re dealing with. The TDS measurement only tells you how many dissolved solids are in your water — not if they’re sharks or rubber duckies.
High TDS levels can indicate a problem that requires follow-up. If there’s something dangerous in your water, you need to know, and if you’re struggling with mineral stains or build-up in your plumbing, knowing which ions are predominant in your water will help you choose the filtration system that best meets your needs. Always do a water test.
What is the difference between a single pass and double pass RO system?
Single pass RO systems filter water through one RO membrane, double pass systems use two. Double pass systems make ultra-pure, lab-quality water like the type used in medical and industrial applications, but they’re very expensive and practical only for commercial purposes. Residential RO systems labeled as multi-stage, are not double pass systems.
What’s the difference between a 2-stage and 3-stage system?
RO systems use pre- and post-filters to improve overall system efficiency and to protect the RO membrane. Each of these filters represents a single “stage.” Sediment pre-filters remove large particles like dirt and rust that can clog other cartridges in the system. Carbon pre-filters remove chlorine — something that can irreparably damage thin-film RO membranes — and carbon post-filters are often added to remove final traces of VOCs and improve water’s taste. In general, more stages of filtration are better, but that can vary based on the quality of individual cartridges.
What does reverse osmosis efficiency mean?
Reverse osmosis efficiency refers to the amount of wastewater produced for each gallon of water purified. With some systems, the ratio can be as high as 12:1. The systems on our list average 1:1 to 3-5:1. Where water costs are high, or local regulations limit brine output, high-efficiency systems save money.
Do I need a Permeate pump?
A permeate pump is a water and energy conservation device. It’s powered by the hydraulic energy of the wastewater reverse osmosis systems produce — no electricity is required.
Permeate pumps enhance the efficiency of RO water systems while improving the longevity of the RO membrane and cutting wastewater production by up to 80-percent.
If your system doesn’t come equipped with a permeate pump, it’s not necessary to add one, but they’re inexpensive, and the benefits make it worth the trouble.
How To Install a Reverse Osmosis Water Filter
The steps to install an RO water system vary by style and manufacturer, but in general, here’s what you’ll need to do:
- Shut off the main water supply.
- Mount the faucet that comes with the kit. Most sinks have an extra hole, but you may have to drill one if it’s already occupied.
- Install the mounting brackets that hold the filter and secure it place.
- Drill a small hole in the water supply line for the saddle valve and connect the filter to it.
- Connect the system to the dispenser and the drain line.
- Flush the system as recommended.
If you’ve never installed a water filter before, it’s helpful to review the instructions in advance. Most provide a tool list and step-by-step directions, and some manufacturers offer instructional videos and technical assistance by phone. If you need to drill a hole in a specialty countertop like granite, consult a professional first.
How to Change Filters in a Reverse Osmosis System
Changing filters in most systems is simple, but variable. In most cases, you’ll need to:
- Prepare the area under the filters with towels and a bucket or tray to catch drips.
- Gather tools like a screwdriver and filter wrench if required.
- Remove filters as directed and replace them with fresh units.
- Run the faucet to check for leaks.
- Dispose of spent filters. Recycle them if you can.
How do I maintain a reverse osmosis system?
Maintaining a reverse osmosis system is a little more complicated than keeping up with garden-variety filters, but the results are worth it. Maintenance is as simple as replacing pre- and post-filters on time — every six to 12 months is typical.
RO membranes last a year or more depending on their total capacity and your water usage. Select systems with tanks may require occasional disinfection — it’s a simple process — and some require periodic back-flushing of the RO membrane to maintain maximum filtration.