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Best Reverse Osmosis Filters

Expert Reviews & Buying Guide

quadcopter reviewsBest Reverse Osmosis Filters

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How to Pick Your RO System

We reviewed 20 new and bestselling reverse osmosis water filter systems to find the best RO systems for your home, ideal for a range of budgets and needs. Let this be your one-stop RO system review and shopping guide - we’ve done the legwork of comparing a range of products, and have narrowed it down to our top overall pick, a budget pick, and eight additional high-quality options. Most of these under sink home reverse osmosis systems support DIY installation, too, so you don’t have to pay for a pro if you have some handy skills if your own.

Best Reverse Osmosis Water Filters

GPD - The production capacity of a reverse osmosis water filter system is measured in Gallons Per Day. But how does that help you figure out the best reverse osmosis filter system for you? Thankfully, you don’t have to measure your household water use personally - it’s easier to go by the estimate of the United States Geological Survey: the average person in the US uses 80-100 gallons a day. Ignoring use that happens outside the home, it’s safe to assume each member of your household uses at least 50 gallons per day. Not all of this is coming out of your sink, of course, but the best reverse osmosis water system for your home should have a higher GPD depending on your water usage. If you have a small household with low water usage overall, a 50 GPD RO under sink filter system should be enough. For heavier usage, you may want to look for home reverse osmosis system closer to 100 GPD if you want to use the filtered water for cooking or cleaning as well as drinking.

Best Reverse Osmosis Filters

99% Contaminant Removal - One of the privileges of living in a developed country is not having to worry about contaminated water. But news stories about water crises can definitely make you wonder, and most people who use wells to provide water to their homes will notice minerals like iron and sulfur that affect the taste, smell, and appearance of their water. Even if you’re on a city water supply, chloramine and other chemicals used to sanitize the water don’t taste so great. One of the best things about an RO water system for your home is that this type of filtering removes water pollutants as small as .0001 microns for, you guessed it, 99% contaminant removal. For context, .0001 microns is smaller than most individual bacteria and viruses. So an undersink reverse osmosis system is certain to provide you with water of great quality, but that looks, tastes, and smells much better than city water.

How to Pick Your RO System

WQA Certified - The Water Quality Association seal is one of the marks of quality to look for in reverse osmosis water filter reviews. This association is a not-for-profit international trade association that represents all levels of the water treatment industry. Companies have to send in an application requesting that their products go through the WQA’s testing process to see if it meets their guidelines for performance, efficiency, and safety. The WQA even audits the facilities where the product is produced before bestowing the Gold Seal mark on the product. This seal lasts five years, and then the product has to be re-tested and certified all over again. Getting certifications from independent organizations like the WQA is a great way for a company to show dedication to consumer protection and a willingness to open up their production process for scrutiny.

Best Reverse Osmosis Filters

Includes Faucet - Although you can hook up an RO water system for your home to an existing faucet, installing a second faucet just for the RO system can help you limit the use of the RO system to things like washing vegetables or filling a cup of water to drink. This way you can use your regular water system for things like filling up a mop bucket or a pot of water for pasta, where taste and absolute purity don’t really matter. Including this faucet is a “bonus feature” that not all RO water systems incorporate, so if you know you want to only use the RO system for certain tasks, it’s really convenient not to have to buy the second faucet separately. Most RO systems make DIY installation easy with video tutorials and customer support numbers, so you’ll have access to experts if you need help installing your home RO system.

Best Reverse Osmosis Water Filters

Warranty - A warranty is there as a promise from the manufacturer that if on the off chance you get a defective product, they won’t leave you hanging. They ensure that the company will repair or replace your RO system if, despite treating it well, it doesn’t perform the way it should. We like loooonnng warranties because they show some serious commitment from the company to the quality of their products. However, a longer warranty also tends to come with a higher price tag--but if you can afford it, we highly recommend investing in a product with a longer warranty. They can offer some peace of mind in a world where things seem to be made with consistently decreasing lifespans. Also, several of these RO systems come with “satisfaction guarantees,” which are basically extended return policies if you change your mind about the system.

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Size - The main limit on an under sink RO filter system is the space available, well, under your sink. A system with a larger GPD tank capacity or one with multiple filter stages comes with lots of benefits, but none of that matters if the system doesn’t fit! Make sure to measure the area under your sink and compare it to the dimensions of the reverse osmosis water system you’re considering. Most of the systems here are about the same size, with a standard three-gallon tank. If you have plenty of room, you can even switch out the tank included by the manufacturer for a larger one if you want. Be wary of things like garbage disposal systems that can eat up available space. It’s always worth double checking your space before buying.

Top 10 Products

Now that you know what to look for in a reverse osmosis water filter system, let's dive right into the reverse osmosis system buying guide below to figure out the best RO filter system for you. The main differences you’ll see between these systems are the GPD and the certifications received from independent industry groups. Rest assured, all winning products on this list offer top quality and value.

APEC Water Ultimate RO-90

Top Pick
The APEC Water Ultimate RO-90 is our pick for the all-around best reverse osmosis water filter. This 90 GPD RO undersink system made in the USA includes a chrome faucet and has gone through several certification processes. The tubing connecting the filter to the faucet is John Guest food-grade tubing that is certified by the NSF (National Science Foundation) and FDA (Food and Drug Administration). It has the WQA Gold Seal, and its NSF-certified 5-stage system ensures ultra-pure water. Plus, their super-capacity filters last twice as long as standard filters (up to 18 months), and the system purifies on average twice as fast as the average RO filter system. The first filter stage uses a polypropylene sediment filter to remove dust and other particles as small as five microns. This helps make the next filtering stages easier on the system. The second and third stage use two carbon block filters with large surface areas to remove the mineral and chemical impurities that affect the taste, odor, and color of your water. The fourth stage introduces a reverse osmosis membrane produced by Dow Chemical, which removes up to 99% of total dissolved solids, including contaminants, bacteria, and viruses. A fifth stage uses an advanced coconut shell carbon filter to refine the water one last time, removing any residual taste from the tank. The four-gallon tank for this system measures 11 x 11 x 15 inches, and each filter is 10 inches tall. The system comes with a one-year satisfaction guarantee warranty and a one-year warranty, which isn’t the longest in the industry, but you also receive free expert technical support for the lifetime of the product to help you work through any issues or questions you come upon. It’s a fantastic product!
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iSpring RCC7 RO Filter System

Budget Pick
The best RO system for a tight budget is the iSpring RRC7. This five-stage system has been tested by the WQA and received their Gold Seal. Like the APEC system, it comes with a one-year satisfaction guarantee, one-year warranty, and lifetime customer support service. A brass brushed nickel faucet is included to help you more efficiently use the system, which can produce 75 GPD. The first stage uses a transparent housing, so it’s easy to see what the RO system is filtering and when it may be time to change the filter. The water goes through three initial stages before entering the reverse osmosis filter. The first filter removes large sediment particles, while the second filter uses a granular activated carbon followed by an even finer carbon filter to prepare the water for the reverse osmosis filter. These filters progressively remove smaller and smaller particles to reduce strain on the reverse osmosis filter, which then removes up to 99% of contaminants. The fifth filter uses carbon derived from coconut shells as a final refining step. This system uses a pressurized tank with a 2.5-gallon capacity that measures 16 x 11 inches, and the rest of the system measures 17.5 x 14.5 x 5.25 inches. This RO system should fit under most sinks, and you can even upgrade the tank to a larger one with some fiddling. The filters are standard rather than the super-capacity filters used by the APEC system, but overall this is a great budget choice for cleaner water at a good GPD rate. Plus, the company supports a streamlined DIY installation process with color-coded tubings and easy-connect fittings, so with their instructional videos and customer support team, you can install the RO system yourself.
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Global Water Reverse Osmosis

The Global Water system is another five-stage RO system with a 50 GPD capacity. It doesn’t have a WQA Gold Seal, but it does use filters and a steel tank both certified by the NSF, as is the included faucet. This set also includes an extra set of four filters for each stage and comes with a one-year warranty. The first filter removes sediment as small as 5 microns with an NSF-certified polypropylene filter. The second filter is a Granular Activated Carbon coconut shell filter to remove materials like chlorine and other dissolved solids, minerals, and chemicals that affect the taste and appearance of your water. The third filter uses a finer carbon filter before sending the water into the RO membrane to remove up to 99% of contaminants. A final “polishing” filter ensures the water is as clear, clean, and good-tasting as possible. This is another DIY RO system thanks to its color-coded tubing and installation kit. The quick-connect fittings make installation quick and easy. Every part of the system is guaranteed lead-free. The 3.2-gallon tank takes up about 14 x 5 x 16 inches total.
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Express Water RO5DX

The Express Water RO5DX is a 50 GPD five-stage filter with 99% contaminant removal, but it lacks the independent certifications from groups like the WQA and NSF we found in other RO filter systems. It comes with a one-year limited warranty as well as a technical support phone service and supports DIY installation. The extra filter set and faucet included are convenient features. This five-stage system uses the same basic setup as others: a 5-micron propylene sediment filter for the first stage, followed by rough and fine carbon filters to remove smaller particles that affect the taste and smell of your water. Then the thin membrane reverse osmosis filter removes up to 99% of other contaminants, and a final polishing carbon filter finishes the job. They emphasise their high-quality, quick-flowing faucet with a flow rate of 0.8 GPM (gallons per minute). The three-gallon tank measures 11 x 15 x 11 inches, and all included parts are free of lead and BPA. The color-coordinated tubing and caps make connections for installing quick and easy. The system is certified “frustration-free” and has a clear instruction manual to follow to have your system up and running as fast as possible.
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APEC Water ROES-50

This APEC filter has a GPD of 50, making it the little brother of our top pick, which is also an APEC filter system. The tubing is food-grade and certified by the NSF and the FDA, plus a WQA certification marks the entire system as well-made. It is made in the USA and comes with a lead-free chrome faucet, and uses regular-capacity filters for its five-stage design. A sediment filter, two carbon filter blocks, the US-made reverse osmosis membrane, and a final refining carbon filter before the water enters the tank. The 11 x 11 x 15-inch tank combined with the 15 x 17-inch area for the filters should fit under most kitchen sinks, and the Quick Connect fittings make installation a breeze. The JG fittings are “truly leak-free,” so you don’t need a leak detector. If you love the design of the APEC Water Ultimate RO-90, the ROES-50 is a comparable substitute. Made from the same quality materials, it is a great option for small households if 90 GPD seems like overkill (after all, 90 gallons is enough to fill your average bathtub to the brim, twice). The one-year manufacturer warranty and satisfaction guarantee are there to back you up if you have any issues.
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iSpring RCC7AK RO Filter System

Our next top pick for the best home reverse osmosis system is another system from iSpring. This 75 GPD six-stage filter has the WQA Gold Seal, plus a one-year warranty and satisfaction guarantee. It comes with a three-gallon tank and a faucet. The filters together measure 18 x 14.5 x 5.25 inches, and the tank measures 16 x 11 inches to fit snugly under your sink. Now, what’s with the six stages, when we’ve only seen five-stage reverse osmosis systems so far? After the familiar initial five stages that send the water through a sediment filter, two carbon filters, the reverse osmosis membrane, and a refining carbon filter, the iSpring RCC7AK adds a special alkaline filter to remineralize the water. A mix of red mineral stone and calcite balance the pH of the purified water and reincorporate minerals like magnesium and potassium that are good for your body and can actually improve the taste of your water. If you’re worried about losing healthy minerals during the purification process or just really like the taste of mineral water, this six-stage system might be for you. In addition, the remineralization raises the pH of the water enough that it will not degrade the storage tank and absorb the tank’s flavor.
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The APEC Ultimate RO-PERM is made in America and uses NSF-certified filters for its five-stage system. Like our top pick from APEC, this RO filter system produces 90 GPD and uses super-capacity filters, so you can spend less time fiddling under your sink and more time enjoying great water. After the one-year limited warranty and satisfaction guarantee are up, you’ll still have lifetime access to an expert customer service team by phone. If you want a home reverse osmosis system, but are worried that your house’s low pressure will keep the tank from ever being full, the APEC Ultimate RO-Perm is made to handle low-pressure areas. Does your PSI never go past 50? No problem. The system uses ultra-efficient technology to fill the tank quickly, and a permeate pump powered by hydraulic energy requires no electricity to run. The high-capacity filters include a sediment filter, two ten-inch carbon block filters, a FILMTEC reverse osmosis membrane from Dow Chemical, and a refining carbon filter before the water enters the holding tank. The manufacturer fully supports DIY installation thanks to the unit’s pre-assembly and detailed instruction manual.
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Aquatic Life RO Buddie

This three-stage reverse osmosis filter earned a spot in our top picks for its compact design. The 50 GPD filter system (which is also available in a four-stage version with a deionization cartridge and a 100 GPD model) does not come with a faucet, only a faucet adapter. It comes with quick connections and mounting brackets. All in all, the system measures 7.25 x 4 x 13.75 inches. This filter system didn’t make our budget pick due to lacking the certifications, stages, and included faucet of the iSpring system. However, this set is a quite affordable reverse osmosis systems and also very compact. If you have the vertical space, this system is ideal for crowded under sink spaces. It has a one-year warranty and takes standard reverse osmosis system filters.
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Home Master RO System

If you have dealt with RO systems before, the Home Master TMAFC RO System aims to solve the issues you may have encountered with low flow rates by using larger tubing sizes. Also, this 50 GPD system remineralizes the water with a seven-stage purification process. The parts used in the unit meet or exceed NSF standards. A faucet is included as well as a year’s worth of bonus filters. This system has the longest warranty of our top picks, coming in at five years. After the sediment filters, carbon filters, RO membrane, and a polishing filter, the two remineralization filters adjust the water’s pH and mineral content for a better taste. This also avoids an issue often encountered with the slightly acidic water produced by the RO membrane: the acidic water “attacks” the tank and can take on an unpleasant taste as a result. The water goes through one filter before entering the tank, then another as it passes through the faucet. The filters add small amounts of calcium and magnesium to improve the taste. The Home Master system also uses a different filter design: you replace the combination filter and filter housing rather than only replacing the filter, which can allow a film to accumulate inside the filter housing. These unique filters are also easy to change without using heavy tools.
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AquaLutio RO Water Filter

The AquaLutio five-stage RO water filter system has a 75 GPD capacity and uses premium NSF-certified filters. It comes with a heavy-duty lead-free chrome faucet and a standard three-gallon tank that measures 11 x 11 x 15 inches. The total system size clocks in at 14 x 15 x 21 inches, by the way. A sediment filter, two carbon filters, a reverse osmosis membrane, and a polishing filter purify the water before it enters the tank. Detailed installation instructions and quick-connect fittings allow you to easy install it yourself. Overall, the AquaLutio RO Water Filter exceeded our expectations. It offers a VERY low price point but doesn’t skimp on quality. We liked the hose fittings which were super quick to attach as well as the high-quality water spigot. It’s also quite simple to flush the RO membrane and as easy to install the entire system. You get excellent value for your money here. If you’re trying to save some money, this is definitely worth a look.
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