The 8 Best Reverse Osmosis Systems of 2023

Best Overall

APEC Water Systems ROES-50 Essence Premium Quality 5-Stage Under-Sink Reverse Osmosis Drinking Water Filter System

4.8

View On Amazon View On Wayfair View On Home Depot

An under-sink reverse osmosis system such as the APEC ROES-50 offers you out-of-sight filtration with on-demand filtered water from a countertop faucet dispenser. This popular pick stands out for its straightforward operation, sizable storage tank, and five-stage filtration. According to the manufacturer, it removes 93 percent of fluoride, 95 percent of iron, and 96 percent of lead and copper. You can expect each filter to last six to 12 months, with the reverse membrane filter and carbon filters lasting up to four years before needing replacement.

The 4-gallon storage tank holds filtered water to be dispensed via the included countertop faucet. This system is rated for 50 gallons per day, which may not be sufficient for large families, but it should be plenty for households of three to four people.

The wastewater-to-clean-water ratio is unremarkable at 3:1, but it’s on par with similarly priced under-sink reverse osmosis systems. You need to devote a significant amount of under-sink cabinet space for this unit. But in return, you enjoy fresh filtered water, long filter life, and simple operation. 

Price at time of publish: $260

_{Tank Size: 4 gallons | Output: 50 gallons per day | Filtration Stages: 5 | Filtration Method: Multi-method | Warranty: 1 year}

Best Budget

Whirlpool WHAROS5 Reverse Osmosis Water Filtration System

View On Amazon View On Home Depot

Investing in a reverse osmosis system doesn’t have to cost a bundle. If you choose a simple system such as the Whirlpool WHAROS5 Reverse Osmosis Water Filtration System, you can have access to freshly filtered water without investing hundreds of dollars or buying cases of water on repeat. We recommend this as the best option for a budget reverse osmosis system, since it removes up to 99 percent of lead and 95 percent of chlorine, carries NSF certification, and offers easy-to-remove filter cartridges. This basic reverse osmosis system has few other features, but it produces filtered, clean-tasting water with minimal installation requirements.

This is a three-stage reverse osmosis system that primarily targets lead and chlorine. Filtered water is available to you from a large, 5-gallon storage tank that pipes water up to the included faucet dispenser. The dispenser is basic by appearance but includes an indicator light to show you when it’s time to replace the filters. 

The biggest recurring expense of any reverse osmosis system is filter replacement. With this system from Whirlpool, you can expect six months of viability from the two-part pre- and post-filter set, and one to three years of use from the reverse osmosis membrane filter. When it is time to change the filters, the encapsulated design makes the filter canisters easy to detach and remove without the need for tools.  

The system takes up more space than some other options, due to its larger storage tank. In addition, no data is available from the manufacturer on wastewater production. If you’re interested in an efficient reverse osmosis system that minimizes water waste, other options may be a better fit. But to kick your bottled water habit and get filtered water on-demand from your sink, the Whirlpool WHAROS5 is a solid system that is straightforward to install and maintain. 

Price at time of publish: $159

_{Tank Size: 5 gallons | Output: 18.46 gallons per day | Filtration Stages: 3 | Filtration Method: Activated carbon, hollow fiber membrane | Warranty: ‎Lifetime warranty available}

Best Splurge

Brio TROE600COL Aquus Reverse Osmosis Water Tankless Filtration System

View On Amazon

The Brio Aquus is a spendy option for a reverse osmosis system, but it frees up cabinet space under the sink while producing up to 600 gallons per day of filtered water. This tankless reverse osmosis system has four filtration stages and impresses with its efficiency. While most reverse osmosis systems produce more wastewater than clean water, this system produces only 1 gallon of wastewater for every 1.5 gallons of clean water.

Another reason to splurge on this reverse osmosis system is the dual-purpose faucet. One handle dispenses filtered water, free of sediment and chlorine, which is commonly used for cleaning or cooking. The handle on the other side of the faucet gives you a stream of purified drinking water. The LCD display on the front of the faucet provides you with a TDS reading and filter life status. 

As with some other tankless reverse osmosis systems, you need to plug this unit into a standard electrical outlet. The single-unit design means that it doesn't take up much space in your sink cabinet—you just need 16.6 inches of height clearance, 18.2 inches of depth, and 5.2 inches of width to make this unit work in your space.

Price at time of publish: $550

_{Tank Size: Not applicable | Output: 600 gallons per day | Filtration Stages: 4 | Filtration Method: Sediment, carbon, carbon block | Warranty: 1 year}

Best Tankless

Waterdrop Reverse Osmosis Drinking Water Filtration System

View On Amazon View On Home Depot View On Walmart

The Waterdrop G3 Reverse Osmosis System is one of the most popular options for homeowners who are interested in saving space and conserving water. This tankless reverse osmosis system stands out for offering a 1:1 wastewater-to-clean-water ratio. It offers fast water production and a faucet with display information regarding total dissolved solids (TDS) and filter life status. Without a water storage tank, this reverse osmosis system takes up less space under the sink. It eliminates worries over bacteria growth inside the tank. The unit measures about 18 inches tall and deep with a width just under 6 inches.

You get eight levels of water filtration when you choose this tankless reverse osmosis system. It reduces TDS, chromium, per- and polyfluorinated substances (PFAS), fluoride, arsenic salt, iron, radium nitrate, calcium, particles, chloride, chlorine, and heavy metals such as lead. All of this filtration doesn’t slow the system down; it’s rated for 400 gallons per day and can fill a glass in about 12 seconds. Three composite filters are responsible for this system’s filtration activities and feature single-turn replacement. 

While some reverse osmosis systems require no power supply, that’s not the case for this tankless model. You need to plug the unit into a standard 110V outlet underneath the sink. 

Price at time of publish: $646

_{Tank Size: Not applicable | Output: 400 gallons per day | Filtration Stages: 8 | Filtration Method: Carbon block, pleated polyester | Warranty: 1 year}

Best Compact

Brondell RC100 H2O+ Circle Reverse Osmosis Water Filtration System

View On Amazon View On Wayfair View On Home Depot

The Brondell H2O+ Circle is our top recommendation for a reverse osmosis water system. This under-sink model offers a compact footprint, minimizes wastewater, and features an LED filter life indicator on the faucet dispenser. Aside from these user-friendly features, this model is certified by the NSF and receives a gold seal from the WQA.

Four-step water filtration inside the Brondell H2O+ Circle removes up to 98 percent of lead and chlorine, plus 84 percent of chlorine. Impressively, the reverse osmosis membrane lasts for up to 2 years before needing replacement. The other three filters have a 6-month lifespan, which is average for most systems. The 6-liter holding tank is smaller than other under-sink reverse osmosis systems, but it makes up for it with a fast refill time of less than an hour. In addition, the filters and tank have an integrated design that requires no electricity for operation. 

Like all reverse osmosis systems, you can expect this method of water filtration to produce waste water. On average, the Brondell H2O+ Circle has a 2:1 waste water to filtered water ratio, which places this system in the top tier of efficiency. It achieves this benchmark by eliminating back pressure on the reverse osmosis membrane. The filtered water is easily dispensed with the included countertop faucet. A unique feature of this faucet is the LED indicator light, which gives you a quick visual of filter status and reminds you when it’s time to change the filters. Swapping out an old filter for a new one is made simple with a twist-and-lock filter system.

Price at time of publish: $380

_{Tank Size: 6 liters | Output: NA | Filtration Stages: 4 | Filtration Method: Carbon block, hollow fiber membrane, sediment | Warranty: 1 year}

Best-Tasting Water

iSpring RCC7AK 6-Stage Under Sink Reverse Osmosis Water Filter System

View On Amazon View On Wayfair View On Home Depot

The iSpring RCC7AK 6-Stage Reverse Osmosis System solves one of the most common complaints surrounding filtered water, namely that it lacks "taste." This is because most reverse osmosis systems remove the minerals that give water a perceptible flavor. Our pick from iSpring includes a final remineralization treatment before dispensing filtered water, restoring the taste profile of the water filling your glass or bottle. “Remineralization is typically to enhance the flavor of the water, because reverse osmosis reduces the level of minerals in the water significantly, and some consumers prefer the taste of the water when there is enhanced mineral content,” explains Rick Andrews, of the National Sanitation Foundation’s Global Water Program. In addition to creating a natural taste, this also raises the pH of the water above 7.5, in comparison to the slightly alkaline water produced by standard reverse osmosis systems. 

The first five filtration stages are intended to remove large particles such as dust, dirt, and rust, plus contaminants that include lead, fluoride, and chlorine. The final filter uses mineral stones to restore healthy levels of calcium, potassium, and magnesium to the water. The storage tank is also pre-pressurized, which produces a more consistent flow when dispensing water and is also beneficial if you connect the water line to your refrigerator.

Take note that waste water production is 3:1 with this system, making it unremarkable in terms of efficiency or water conservation. Installation can also be more challenging when compared with some other under-sink reverse osmosis systems, but it can be accomplished with basic tools and some understanding of home plumbing. A water line kit is included if you want to connect your refrigerator’s water line to the reverse osmosis system. 

Price at time of publish: $279

_{Tank Size: 3.2 gallons | Output: 75 gallons per day | Filtration Stages: 6 | Filtration Method: Reverse osmosis, alkaline, activated carbon, carbon block | Warranty: 1 year}

Best for Apartments

Brio ROP100 Amphora Reverse Osmosis Under Sink Filtration System

View On Amazon View On Home Depot View On Walmart

Typical reverse osmosis systems take up considerable space in the sink cabinet and require a countertop-mounted faucet dispenser. For renters, giving up a ton of space underneath the sink or installing a new fixture on the countertop may not be feasible. The good news is that reverse osmosis systems exist that require minimal installation. Our top recommendation for apartments is the Brio Amphora Reverse Osmosis Under Sink Filtration System. It offers three-stage water filtration, housed inside a slim, tower-style unit. Filtered water is pumped to a refillable 2.5-liter carafe that sits on your countertop rather than being dispensed through a separate faucet that requires installation. 

In apartments, condos, or other small spaces, this type of reverse osmosis system is a great option. The under- sink system measures 14 inches tall, with a 6.75-inch footprint. It saves considerable space by condensing the filters into a single cartridge and forgoing a storage tank for filtered water. Instead, water is pumped to a countertop carafe that sits on display with an included base. A sensor automatically refills the carafe, ensuring that you never run dry. Note that the base of the carafe must be plugged in for operation. You’ll also need a path for the tube to bring water from the filtration system to the carafe. 

Price at time of publish: $241

_{Tank Size: 2.5 liters | Output: Not listed | Filtration Stages: 3 | Filtration Method: Carbon block, sediment | Warranty: 1 year}