The PROs and CONs of Reverse Osmosis

Reverse Osmosis nowadays is among the most popular and accessible ways to purify water at home. The technology has been around since 1977. Some countries and parts of the U.S. are using Reverse Osmosis as a key part of the municipal water filtration process.

To put it simply, Reverse Osmosis is a method that pushes water through a membrane so fine that only water molecules can pass. Everything else gets left behind. This includes unwanted contaminants and beneficial minerals, but more on that later. The leftover particles are considered waste and get flushed down the drain with additional water. There are upsides and downsides of RO. But the technological progress does not stay in place so as well see later, PROs are continuously outweighing the CONs.

Benefits of Reverse Osmosis

By removing impurities, Reverse Osmosis improves water smell, taste, and appearance.

Removes 95% – 99% of total dissolved solids (TDS)

Reverse osmosis is the most effective way to drop the unwanted amounts of total dissolved solids in water. This includes Chlorine, Fluoride, Pesticides, Lead, Arsenic, Nitrate, Microbiological contamination, Chromium, Copper, and heavy metals. Such a robust process of water purification is beneficial for both municipality water users and private well owners. Drinking contaminated water in the long term can result in unpleasant side effects.

Improves the taste and odor of your water

Water tastes, well, like water. But not all water made of equal mineral composition. The stuff you don’t want and that is harmful makes water taste and smell bad. So by filtering that out you get pure and fresh-tasting water that is not harmful in any way. This is already a good thing, but the taste can be improved further by remineralizing water and more on that here.

Allows people to drink more water

If you want to change your habits of drinking pour quality drinks then you need to set yourself up for success right from the beginning. Reverse Osmosis makes good and tasty water. And by having it always available you can form that habit of hydrating yourself well and often. This is vital for our health because most people drink less water than they should be.

Better for the environment

Your personal RO system can encourage you to stop buying bottled water which is among the biggest sources of plastic pollution today. Of course, there are RO filters in plastic casings that will go to waste. But on average that could be a lower carbon footprint that years worth of plastic bottles. Especially if you multiply that by a whole family.

Comes with additional filtration levels

For even more optimal purification processes Reverse Osmosis systems have a number of additional filters. Such as Activated Carbon, Sediment, or even Ultraviolet light treatment filters.

The Reverse Osmosis membrane takes a center stage of the purification process. But the overall quality of filtered water is boosted to a new level.

Improves the taste of your hot drinks and food

Coffee and tea made with the right pH water that is pure will taste so much better. The same goes for the food you’re cooking at home. Some RO systems can even adjust for the perfect pH that you’re looking for.

Stops hard water mineral deposits and stains

Technically speaking, water higher in pH does not result in water stains. It’s doubly important if in your household or business you run glasses need to be spotless and sparkling clean. RO treated water makes life so much easier.

Reverse Osmosis filtration system is almost fully automated

Once installed and set up an under sink or countertop RO water filter system simply works, without you needing to do much for it. There is periodical filter replacement which is to be expected. The filters most often last between 6 to 12 months and RO membranes last for about 2 to 3 years. To be fair, some systems need to be cleaned once a year, especially if you live where water is exceptionally bad. I have a separate article on how to do just that. It can be considered a bother. But that’s a low price to pay for a huge problem of poor water that the RO system is solving.

Energy efficient

To be fair, there are no perfectly efficient RO systems and you should choose the one that works best for your situation. Some of the RO systems require no electricity at all. The RO process is made to happen by the pressure of incoming water through the pipes.  However, these systems will waste more water on average. The pressure should be around 60psi for such a system to work properly. If you get your water for free or it costs cheap, this might work great.

Other systems solve this by having a pump and even some advanced water recycling technologies. But they require electricity to run. So pick the one that works for you.

There’s a middle ground, however. Some systems have a permeate pump that does not require electricity. The permeate pump solves the low incoming water pressure problem but needs a bit more work to install.


Well, obviously, Reverse Osmosis systems do cost. So do the filters that need to be changed. The total price might look high, however, that is a short-sighted view. When taken into consideration all the water bottles you buy, or even possible ill-health effects of not drinking enough water, then the cost of RO system is so worth it. If you pick the system and do the counting then you can clearly see that the price per gallon over a year is lower than that of bottled water.


Well, the final benefit of this list is that nowadays you have so many options. There are countertop RO systems that require no installation at all. Some of them are even portable and you can take them with you or they work well on Motorhomes There are more powerful under the sink RO systems. There are RO systems built into cold and hot water dispensers. And there are plenty of good manufactures to choose from that suit all budgets and situations.

Disadvantages of Reverse Osmosis system

In the same way that there is a benefit, there’s another side of the coin where advantage could come with drawbacks. These are not faults but more as drawbacks that can be bypassed with the right expectations and decisions.

The time it takes to purify water

Reverse Osmosis is not a very fast way to get clean water. Most often the water will not be free-flowing as it does from the simple tap. Since there are more than a few filters involved. If the system you pick is simple in design and has no electric or permeate pump, then the flow rate can be slow.

Under the sink systems and some countertop ones solve this by having a storage tank that automatically tops up after the water is let out. So you have some gallons of water available and more will be filtered in a matter of time.

Water wasting

RO systems are known to produce wastewater and some people get notoriously angry about that. I’ve covered this issue above. You need to pick between a less expensive system without a pump or one with a pump that saves water.

This becomes an issue if your water is really dirty and the membrane will work harder and will need more water to clean itself up. Or the water pressure coming into the system is insufficient.

Possible clogging

This is a rather rare issue, but the tiny pores in the semipermeable RO membrane can get clogged. And then it has to be changed prior to schedule replacement. This happens if the whole system is not properly maintained. For example, the filers were not changed in time. Or something was assembled in the wrong way and dirty water was bypassing prior filters.

Usually, RO systems come with three or four filters that stand before the RO membrane, to assist it and reduce the likelihood of clogging it with dirt.

Ongoing filter replacement

If you get a system, then you’re up for changing filters. With some manufactures, it’s easier and simpler than with others. Sometimes you’re bound to the same manufacturer that made the system, sometimes you’re not.

Some systems come with ways of tracking time or even displaying the state of output water and filter life. Others need more guesswork and note-keeping.

Removal of beneficial minerals

If the water you’re getting is really bad then the only way to purify it is to remove everything in it, including good minerals and leave it simply pure. On rare occasions, you might not like the taste of it. The way to solve it is easy. You can remineralize your water with these simple steps. Alternatively, some RO systems come with a remineralization unit included so the water comes out healthier and with a proper pH.

Dropping the pH scale

Yes, RO purified water is lower in pH. Simply speaking, because it’s lacking certain minerals that were removed. It’s not harmful and there are no side effects of drinking RO water. Once again, you can change the pH with rather simple tricks. Or some systems can normalize the pH for you.

Is it worth getting a Reverse Osmosis system?

Sure it is. There are advantages and disadvantages but I believe that PROs strongly outweigh the CONs. Looking in the future, the accessibility to drinking water becomes a question more and more raised in the public discussion.

In some places faster than others. Some countries and municipalities are already using RO systems on a massive scale to desalinate the seawater and make it drinkable. So RO could as well be the technology of the future to purify healthy drinking water and make it accessible to everyone.

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