The Pros and Cons of Reverse Osmosis Filtration

Do the benefits of reverse osmosis outweigh the downsides?

By: Alyssa Scavetta

Reverse osmosis is one of the most effective methods of water filtration technology. For example, many countries are using reverse osmosis to desalinate seawater in an effort to combat water shortages in key locations. Currently, most of the operating desalination plants provide water in the Middle East or North Africa (44%). However, as water accessibility becomes more urgent (and as the effects of climate change start to uncover new needs across the globe), scientists expect that salination capacity will grow 7% to 9% annually — and that’s all by using reverse osmosis on a large scale.

On a smaller scale, the benefits of reverse osmosis have made it a popular choice among consumers for filtering the water in their homes. Additionally, many restaurants are using reverse osmosis to improve the safety and taste of their food by using the best quality water.

The sheer capabilities of reverse osmosis can be overwhelming, so we’ve broken down everything you need to know including what it is, how it works, and what are its pros and cons? Let’s take a look.

What is reverse osmosis filtration?

Reverse osmosis is a water filtration method that forces water through a semi-permeable membrane at a high pressure, leaving all particles larger than the net behind. In this sense, the semi-permeable membrane filters contaminants on a molecular level, catching microscopic particles including chemicals, sediment, microorganisms, and metals. As pressurized water goes through, contaminants get caught and only filtered water gets to the other side to use for drinking, cooking, bathing, or any other purpose.

"Reverse osmosis is a water filtration method that forces water through a semi-permeable membrane at a high pressure, leaving all particles larger than the net behind."

How does reverse osmosis filtration work?

The reverse osmosis process essentially sifts out particles that are larger than 0.01 micrometers or larger in size, which can include many types of sediment, bacteria, and even fluoride and lead particulates.

It’s also important to note that the reverse osmosis process does not require thermal energy, and instead, relies on high-pressure pumps. In layman’s terms? This means that it doesn’t require access to a power supply, it just needs a lot of water pressure.

As an example, for brackish water (water with more salinity than fresh water, but not as much as sea water), the water pressure flowing through your reverse osmosis system will be between 225 and 376 pressure-per-square-inch (psi). That’s more than 6x the average water pressure to a standard size home (usually between 40 to 45 psi). This intense pressure pushes water through the semi-permeable membrane, leaving impurities behind and providing you with healthier, better tasting water.

The benefits of reverse osmosis water filtration

There are many benefits of reverse osmosis filtration. With more than 77% of Americans using some form of water filtration in their homes, and a percentage of that being reverse osmosis, let’s see the benefits they’re receiving.

Pro #1: Reverse osmosis filters the most contaminants

When it comes to removing the most contaminants, reverse osmosis stands out from the water filtration pack. The Environmental Protection Agency (EPA) cites reverse osmosis as one of the most “effective in eliminating all disease-causing organisms and most chemical contaminants.”

For example, the Aquasana SmartFlow™ Reverse Osmosis Filter is Water Quality Association tested and certified to NSF/ANSI Standards 42, 53, 58, 401, and CSA B483.1 for the removal of 95% of fluoride and mercury, 97% of chlorine and arsenic, 99% of lead and asbestos plus 83 additional contaminants. While many reverse osmosis systems inadvertently remove healthy minerals as well, Aquasana’s system adds those back through a remineralization process that restores beneficial minerals.

Pro #2: Reverse osmosis is a safe alternative to bottled water

It’s no secret that plastic bottles are bad for the environment, but few people realize that filtered water (such as reverse osmosis) may actually be safer than using disposable bottles every day. The bottled water industry is notorious for lack of regulation and as the New York Times pointed out, “the FDA does not require bottled water companies to disclose to consumers where the water came from, how it has been treated or what contaminants it contains.”

By comparison, Aquasana’s SmartFlow™ Reverse Osmosis is certified to strict NSF/ANSI standards so you know exactly what contaminants are being removed/reduced and to what degree. Furthermore, using a reverse osmosis water filter is far-more environmentally friendly than plastic bottles, and adds convenience since you only need to turn on the faucet to enjoy healthy, great-tasting water.


SmartFlow™ Reverse Osmosis

High-efficiency reverse osmosis system removes up to 99.99% of 90 contaminants, including fluoride, arsenic, chlorine, and lead.

Pro #3: Reverse osmosis provides better water for cooking

Many restaurants have started using reverse osmosis water to wash ingredients and cook with in order to improve the taste of their food. In fact, Chef and Owner of Crop Bistro & Bar Steve Schimoler noted:

“I never gave much thought to the water I used until I had the opportunity to research the role that water plays in my kitchen and restaurant. I quickly found the water that was purified using reverse osmosis (RO) technology provided me with a clean canvas which allowed the flavors and ingredients I used to shine.”

While the benefits of reverse osmosis are making it a standard in the foodservice industry, you can also use an RO system to give your home cooking an added boost.

The disadvantages of reverse osmosis filtration

So while it is the most effective water filtration technique on the market — preventing particles as small as fluoride from entering your water — it’s also inefficient from an eco-friendly standpoint.

Con #1: More water wasted

According to the EPA, “Reverse osmosis units use approximately three times as much water as they treat,” which may be reflected on your water bill. In fact, some household reverse osmosis systems only recover between 5%-15% of the water they filter.

Additionally, there aren’t many options for the proper disposal of wastewater. You can dispose of the wastewater into the sea, but for those who are landlocked, you should consider an evaporation system to avoid runoff or groundwater contamination, as it can be detrimental to the ecosystem.

Con #2: Some noticeable pressure drop

While the Aquasana SmartFlow™ Reverse Osmosis features a reliable flow rate of 0.8 gallons per minute, many people who use alternative reverse osmosis filters experience a fairly noticeable pressure drop in their water flow rate.

Con #3: Loss of minerals

Reverse osmosis is such a powerful filtration method, that in addition to contaminants, it also removes healthy minerals. By removing good minerals from your water, it loses some of the health benefits and can also have an off taste which makes it less enjoyable to drink. To counteract this, some systems, like the Aquasana SmartFlow™ Reverse Osmosis, include a remineralizer to restore beneficial minerals that would otherwise be lost.

Is reverse osmosis worth it?

Reverse osmosis is a popular method of water filtration, but it comes with pros and cons that each person will need to consider to determine if an RO filter is right for them. If you’re looking for maximum contaminant removal in the water you use for cooking and drinking, you’ll find that reverse osmosis filters are a great solution with more convenience than bottled water. However, you should be mindful that these systems create wastewater and some systems lower your water pressure and remove minerals.

At Aquasana, we take pride in making our reverse osmosis system the most efficient, reliable, and durable water filtration system on the market. The SmartFlow™ Reverse Osmosis filter reduces 15x the contaminants of the leading pitcher filter brand. Plus, with the included remineralizer, you’ll get healthy amounts of calcium, magnesium and potassium for optimally alkaline, pH balanced water. Shop now to enjoy the benefits of reverse osmosis in your home.