What is Reverse Osmosis (RO) Water? Is R.O. Water good for you?

by Asaiah Passwater / Apr 24, 2019
What is Reverse Osmosis (RO) Water? Is R.O. Water good for you?


Clean drinking water is hard to come by, and in today's day and age, many options claim to give you the "best water," "healthiest water," or "purest water." Even if you live in an area where your water is clear and tastes good, it is still highly likely that harmful contaminants and chemicals are present. You can't see, taste, or smell them, but testing shows they are there! Toxins like pesticides, Chromium 6 (the Erin Brockovich contaminant), lead, arsenic, and many others are commonly found in tap water supplies across the US and the rest of the world.

So what filtration system is the best to remove the contaminants in your tap water? Many people believe that Reverse Osmosis (RO) is the most effective option for ensuring your water is free and clear of all toxins, but that is not necessarily the case. Yes, RO water is likely safer than your original tap water, but is it the safest or even the best option available?


How Reverse Osmosis filtration works

Reverse Osmosis is the scientific name for a specific type of water filtration. RO systems are designed to force untreated (tap) water through a series of carbon filters and semipermeable membranes. These physical barriers have pore sizes that are small enough to stop harmful toxins and heavy metals like lead, manganese, arsenic, and chromium from passing through. However, the water system also blocks most beneficial minerals, producing demineralized water. Reverse Osmosis removes more than 99.9% of all Total Dissolved Solids (TDS) from drinking water. Some people call this "dead water" because it does not contain the healthy minerals naturally present, such as magnesium, calcium, potassium, and sodium. Deficiencies of those healthy minerals have the potential of causing serious health issues. Calcium deficiency leads to brittle bones, magnesium and potassium deficit contributes to high blood pressure, and reduced iron intake from demineralized water interferes with blood formation. Reverse Osmosis removes everything too big to fit through the membrane, both the good stuff and the bad.

Due to the greatly reduced mineral content from the RO water treatment, many RO systems include a remineralization filter. According to the World Health Organization, reintroducing magnesium and calcium into demineralized water in the remineralization process can provide health benefits.

Reverse Osmosis systems can be large enough to supply water to sizable municipalities and also small enough to fit under a kitchen sink. Because of the filter’s effectiveness at filtering toxins and contaminants, many people think that RO systems are the only way to get pure water from your kitchen tap. This is not necessarily true.

How does reverse osmosis work?

Is drinking Reverse Osmosis water good or bad for you?

There are both advantages and disadvantages to installing and/or drinking RO water. Living in an area with numerous water quality issues or specific types of  contamination in the water sources is enough reason to consider an RO system or at least a water purification solution that does more than a standard carbon filter. The health effects of heavy metals, chemical runoff, and other toxic impurities can be substantial.

In addition, there is a side effect on the purified water from an RO system: the low mineral content causes purified water to leach minerals from the human body. Even a high-quality RO purifier with a remineralization add-on won't add every beneficial mineral found in healthy American alkaline water back into the treated water. Once again, according to a WHO report, "possibly none of the commonly used ways of remineralization could be considered optimum since the water does not contain all of its beneficial components. In the case of borderline deficiency of a given element, even the relatively low intake of the element with drinking water may play a relevant protective role."

Other things to consider before installing a Reverse Osmosis Water Filter system

We've identified 5 important reasons why you might want to think twice before getting an RO system:

1: Size

Reverse Osmosis systems take up A LOT more room simply because they require a storage tank. The tank itself must be connected to the water filter system and the tap, so they must be close together, limiting your options for where to place it underneath your sink.

2: Installation

Installation of a Reverse Osmosis system is complicated and cumbersome at best. Unless you are extremely handy and have a garage full of tools, you probably shouldn't even attempt to put it in on your own. The chances of a non-plumber being able to install one of these systems is not very good. With holes needing to be drilled in both your countertop and wastewater line for the dedicated faucet and the discarded (or purged) water, you're talking about a set of tools and knowledge that is fit for an expert. And the risk of messing it up and causing a leak somewhere is high.

3: Cost 

Curiously, the upfront cost of an RO system is comparable to other options. . The RO system will have cheaper filters (called membranes) than other systems, but that is where the similarities stop. Using an RO system can be expensive due to what is called the water rejection rate. Using an RO system will increase your water bill because it flushes 3 gallons of water down the drain for every 1 gallon of clean water it produces. This is a hidden expense many people do not factor into an RO system's overall cost of ownership. 

A system like the Clearly Filtered Kitchen Sink Filter System has a similar installation cost, and the filters are more expensive than the RO system, but there is no wastewater produced, limiting its lifetime cost. The Clearly Filtered system is a closed system where every drop that goes through one side comes out the other, making it the more efficient option.

4: Effectiveness or performance 

As we mentioned before, RO filters are usually pretty good at targeting toxins in water, but they also strip the healthy trace minerals from the water in the process. They filter most standard water contaminants such as lead or chlorine. However, we see the performance vary significantly from model to model, so it is essential to find out how the model you are considering has been tested. 

If a RO system is going to be worth the extra lifetime cost, make sure it outperforms the Clearly Filtered System’s highly rated filtering technology. You can find how well our filtration system works for things like fluoride, PFOA/PFAS, BPA, and pesticides here

5: Ease of Upkeep

The most difficult part of upkeeping any water filtration system is changing filters. Most RO systems have a complicated filter changing process. For one, there are between 5 and 7 different filters that each need a special wrench to access, and you have to shut off the water supply to the system before removing any of them. To make things even MORE complicated, the filters on an RO system need to be changed at different intervals. Each stage requires separate schedules for filter replacement, making it something only the most organized individuals will be able to keep track of. There are also gaskets that they recommend re-greasing and more than a dozen fittings to check for leaks. It's best left to a professional, which, again, increases the cost of maintenance. 

On the other hand, it's extremely easy to replace the filters on your Clearly Filtered Kitchen System (most customers do this once a year on a subscription). There is no need for any tools at all, and it is nearly foolproof. 

Healthy Water for the Right Price

Systems like the Clearly Filtered Under-the-Sink System have filled the void left by overpriced RO systems, and have actually surpassed some competing RO systems in both water quality and price. With the above 5 reasons in mind, it’s evident that Clearly Filtered is the better option for anyone looking to get clean and healthy water straight from their kitchen tap.