Best Reverse Osmosis Systems

The Aquasana OptimoH2O has impeccable filtering, here are some of the main contaminants it can reduce or remove:

• Lead: 96.6%
• Chlorine: 97.66%
• Arsenic: 97.6%
• Cysts: >99.99%
• Emerging compounds: >94.2%
• PFAS: 96%
• Asbestos: 99%

Performance data sheet

Being tested and certified by the NSF to NSF/ANSI standards 42, 53, 58, 401 + P473, it is one of the most comprehensively certified RO systems available. 

The Aquasana OptimoH20 utilizes a reverse osmosis membrane to reduce 14 impurities, and a patented Claryum filtration method to reduce 60 other contaminants. The filtering process is finished by remineralizing the filtered water with healthy amounts of calcium, magnesium, and potassium, which provides alkaline, pH balanced water. Here is a breakdown of the 3 stages + remineralization:

1. Carbon filtration: Reduces organic chemicals, VOCs and MTBE
2. RO membrane filtration: Filters out dissolved solids smaller than 1 micron including heavy metals.
3. Claryum filtration: Targets chlorine and chloramine (aesthetic issues)
4. Remineralization: Healthy amounts of minerals are absorbed back into the purified water to raise the pH level to a balanced level.

The Aquasana OptimoH20 is also our best RO system water filter for well water. With over 13 million American households relying on well water for drinking, it’s important to keep the water you drink from your well clean. Well water can have microorganisms such as bacteria, viruses and parasites in it, as well as nitrates, heavy metals, organic chemicals, radionuclides, and fluoride. 

Essentially anything that can contaminate water can be in a well water source depending on where you live. The Aquasana filters 99% of bacteria, putting it in the top 1% of RO systems we assessed.

The filter life for the Aquasana Optimo is solid with the Carbon and Clayrum filters needing to be replaced every 6 months or 365 gallons, which will cost you ~$65. The RO membrane needs to be changed every 1-2 years according to Aquasana and will cost ~$60, and the remineralizer costs ~$30 and needs changing once a year. If you use less water in your home than you’ll only need to replace the RO membrane once every 2-3 years.

The total system and running cost (filter replacements) for 5 years will cost approximately ~$815, which is an amazing deal considering you are getting the best RO water filter on the market.

The system can give you up to 32 gallons per day, men require about a gallon of water a day, and women require just under 3/4 of a gallon a day according to the Mayo Clinic. So if you take this into account, it can provide enough drinking water for a large family.

Reverse osmosis systems require adequate water pressure to be able to function effectively. Before purchasing, you’re going to want to make sure you have at least 40 psi in your home.

If your home’s water pressure is below 40 psi, you’ll want to look for a RO model that has a booster pump. If your home uses well water, you’ll need to make sure the well pressure of the tank is set high enough to let the RO system work best.

Filter capacity depends on how much water you and yours are going to be using. Are you using it for drinking, washing, ice trays, or a combination of all three? Different systems filter different amounts so you’ll need to adapt accordingly. 

If you are just looking for an RO system to fulfill your drinking water needs, then get a system that gives at least 9 gpd. 

If you want to soak some dishes as well, then systems over 10 gpd will be better. And if you are a large family that will be using an abundance of filtered water, then a system that can filter over 30 gpd may be best. 

Some models promote being able to filter 400 gpd, but this is unnecessary, no one will use that much water in a day, and if you do, you’re likely being very environmentally irresponsible.

An unfortunate downside to RO systems is that they can create a lot of wastewater. 

Ideally you’ll want to look for systems with 1:1 to 3:1 ratios if wastewater is something you’re concerned with. Consumers can also find systems designed to reduce waste by repurposing it towards other hydro uses like gardening or dishwashing. 

Systems with 1:1 ratios that are certified are difficult to find, and often they do not make their performance data readily available. 

With reverse osmosis systems, the drain ratio average is 3:1. High ratios hover around 5:1, but to reduce many contaminants these systems usually need excess water to drain out contaminants.

We suggest you look for a model around the average 3:1 ratio, but don’t rule out higher ratio models, especially if you can repurpose excess water. We suggest using it for watering gardens.

Most RO systems require installation meaning a dedicated faucet and drain connection. If you’re a renter and can’t install a faucet or alter the already built-in plumbing, you’ll want to consider a countertop model, pitcher, or other filtration method. 

If you’re a homeowner and you’re willing to do minor alterations, the RO system will be a great and long-lasting filtration option. 

People with a ‘can do’ attitude and minor DIY skills will be adept at installing RO systems in a matter of minutes by following easy-to-follow instructions that come with every product. Some of which even offer instructional videos.

RO systems are designed to strip the water of not only its harmful contaminants, but also valuable minerals. The process makes the water slightly acidic, to restore pH levels some models offer remineralization. 

The remineralization feature inserts healthy and valuable minerals back into the water at the end of the filtration process. If you’re looking for healthy minerals in your water, consider models that offer remineralization.

RO systems have a wide-range of pricing with low-end products at $100 and “premium models”at $1,000. Marketing teams will try and lead you to believe that more expensive units offer more filtration stages that can filter more water at a time. This is however not always correct. 

We’ve found the best products or usually in that mid-range price category. Mid-range products will get the job done, and you won’t be spending needless $.  We recommend spending around $200-300 for the purchase of a reverse osmosis system. 

In addition, you’ll also want to take into consideration the annual cost of having a filter system, like individual filter replacements. You’ll likely save money on all the bottled water you won’t be buying anymore.

RO systems usually have multiple filters with different lifespans so it might be beneficial to protect your investment with a warranty. 

Some products offer multiple-year warranties and we’d recommend buying products with at least a one-year warranty. 

So, with all that said, here are some more of our best reverse osmosis systems to consider going forward. We tried to give you a range of specifics to help cover as much ground as possible.  

Here are the contaminants it reduces:

• Lead: 96.8%
• Fluoride: 93.8%
• Arsenic: 99%
• Chromium: 99%
• Copper: 98.4%
• Turbidity: 98.7%
• Barium: 98.8%
• Cadmium: 98.3%
• Radium: 98.8%
• Selenium: 97.8%

The WQA has certified this product to NSF/ANSI standard of 58 so you know you are getting a quality under sink water filter that has been through rigorous independent testing. 

This is a 6-stage filtration system, meaning it has 6 different filters. Each stage has its own unique filtering capability: 

1. Sediment filter: removes dust, particles, and rust.
2. Carbon block filter: removes chlorine and chloramine and any associated odor and taste
3. Carbon filter: removes VOCs and other common chemicals
4. Reverse osmosis membrane: filters harmful contaminants including arsenic, lead, fluoride, chromium, radium and more.
5. Coconut shell refining carbon: removes any residual taste from RO tank
6. Calcium carbonate remineralization: increase pH level by adding calcium carbonate mineral back into the water.

That’s a lot of filters! Fortunately these filters can be purchased as a complete set. However, like most RO systems the filters need to be changed at different times, as some filters have shorter lifespans. The shortest is 1 year, and the longest is the RO membrane which lasts 3 to 5 years (depending on use). So you won’t be changing filters often. 

The price for 6 filter replacements is around $150, so it’s a great bang for your buck. The majority of under sink filters/reverse osmosis need filter changes at least once every 6 months, so this system is a step above. 

This system is suitable for houses with water pressure between 40-85 psi. This will cover the vast majority of homes water pressures, the average psi of homes is 50 and the maximum is 80. 

This model has a 4 Gal. storage tank, so when that is full the dedicated faucet flows freely. And the storage tank begins to refill as water is used.  The system can filter 90 GPD. For reference, it is recommended to drink ½ to 1 gallon of water a day per person, so if you have a large family it has you covered (and more). 

For the price of just under $350 this comprehensive system has all your drinking needs covered. The 5 year cost for this system including purchase is approximately ~$900.

Its ongoing costs (filter replacements) are low, so this system will be cheaper than most other under sink/reverse osmosis systems long term. 

The APEC comes with a 1-year warranty and lifetime technical support for peace of mind.

Not only will you have water on demand, you’ll have quality filtered water. Being certified to NSF 58 to reduce the following contaminants:

• Lead: 98.6%
• Copper: 98.3%
• Turbidity: 99.1%
• Fluoride: 94%
• Radium: 95.1%
• Selenium: 97%
• TDS: 94.7%
• Cysts: 99.99%

Performance data sheet

Not only is this a quality system in terms of filtering, but it comes at an affordable price just under $150. Annual filter replacements will cost about $85, which is the lowest on our list. So for long term value this is a great reverse osmosis system. 

A slight downside to this system is that it provides less gallons per day than other systems on the list. But if you only plan on using this system for drinking and light washing then it will have you covered. Many systems provide a greater daily capacity than you could ever really use.

Low costs, but big filtering! This system performs just as well as other RO systems. It is certified to NSF 58 for the reduction of the following contaminants:

• Lead: 99.1%
• Arsenic: 98.2%
• Fluoride: 96.5%
• Turbidity: 99%
• TDS: 90.6%
• Chlorine: 95.2%
• Copper: 98.8%

Performance data sheet

Not only is this product affordable, has great filtering, but it comes with a solid 2 year warranty. 

It provides more than adequate filtering capacity being rated to filter 18.46 gallons per day. A downside is that it does not offer remineralization.

The Brondell Circle brands itself as being ten times more efficient than a lot of other RO systems on the market and it’s simple to install in a complete all-in-one system.

Besides being NSF 42, 53, 58, 372, and WQA certified, this unit is attractive enough that it makes you think it was designed to be a countertop system. Here are some of the contaminants that the Brondell can reduce/remove:

• Lead: 98.2%
• Copper: 98.7%
• Fluoride: 83.8%
• Chlorine: 98.4%
• VOCs: 99.8%
• Cysts: 99.96%

The under-sink system has a daily filtering capacity of 56 gpd and works at a 2:1 waste water ratio. The product has a one year warranty and considering its design is so respected, its $279.99 price tag isn’t too shabby either. 

The four-stage filtration system includes a chrome tap and faucet and features a sleek LED light to indicate when its filters need to be changed. 

Speaking of, the system uses multiple filters which range from $69.99 to $79.99. But again, consumers are coming to the Brondell Circle because of its design and we’ve chosen it as our best designed RO system.