RO Water Remineralization 101 – Full How-To Guide

salt with water glass

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Reverse Osmosis Water

If you aren’t visiting our blog for the first time, you already know that reverse osmosis is the most commonly used technology to purify water.  In the process, water passes through a semipermeable membrane at relatively high pressure leaving almost all dissolved solids behind.

Various industries use ro water for their applications, but it can also be found in supermarkets in form of bottled drinking water and many people have an ro water filter system installed under their kitchen sink.

Apart from the fact that the use of such a system increases the amount of water that gets wasted, there aren’t any drawbacks that come with it, except…

The Little Problem with Reverse Osmosis Water

Up to 99% of all Total Dissolved Solids (TDS) are removed from water during the filtration process. This does not only include harmful substances such as chemical contaminants (e.g. medication residues), but also minerals that are essential for the human body like calcium and magnesium.

In other words, reverse osmosis water is severely demineralized. This could cause problems since according to the WHO in case of “calcium and magnesium water may provide up to 20% of the required total daily intake”. What’s more, due to industrial agriculture, deficient diets, impaired digestion and high stress levels some people may already suffer under mineral deficiency.

Please Note
The goal of this post is not to frighten anybody and we absolutely don’t know whether or not drinking ro water over a long period of time will cause any health problems, we simply want to point out the issue and provide all the necessary information you need.By the way, there is no reason to worry about mineral deficiency in regards to other minerals, because the WHO also states that “For the majority of other elements drinking water provides less than 5% of total intake”. These elements include iron, zinc, copper, iodine, phosphorus and chloride among others.

How to Add Minerals Back to Reverse Osmosis Water

A logical solution to demineralization would be to add essential minerals back into the water after filtration. You might now think that this must be a rather complicated process – but it’s not. But before we give you 5 options on how to remineralize, let’s take a closer look at calcium and magnesium, which hold the highest percentage of the required total daily intake (TDI) that is provided by water.

calcium stonesCalcium

Calcium is the most abundant mineral in the human body and accounts for 1.5 – 2.0% of our total body weight. Most of it is stored in the skeleton as a primary structural building block. Other functions of calcium are the regulation of enzymes and hormones, blood clotting, nerve transmission and muscle/vascular contraction.

A decrease in bone mineral content, resulting in weaker bones and ultimately an increased risk for fractures are the consequences of longterm calcium deficiency.

The World Health Organization recommends a minimum of 20mg/l and an optimum of about 40-80mg/l of calcium in drinking water for a maximum beneficial health effect.


Magnesium is the second most abundant intracellular cation. 20 – 28g of magnesium are stored in our body. About 60% of it is found in the skeleton and 1% in extracellular fluid. 300 enzymatic reactions depend on magnesium and the mineral is also essential for the development of our bones.

The WHO points out that magnesium deficiency has been implicated in hypertension and type II diabetes. A low magnesium intake has been associated with an increased risk of cardiovascular diseases.

The recommended minimum amount of dissolved magnesium in drinking water is 10mg/l and the optimum amount being 20-30 mg/l.


Now that we know how important calcium and magnesium are, how do we manage do get them back into our drinking water?

Alkalinization Stage for your RO System

If your ro system does not already feature an alkalinization stage, one probably can be added to it without too much effort. Browse the market for models using food-grade quality minerals only, such as the ROALK5D 10-Stage ro system. Depending on your water demand the minerals will last for 6 to 12 months.

Also, water temperature, flow rate and pH-level (before it enters the alkalinization stage) determine how much minerals are added back into the water.

Electrolyte Blends/Trace Mineral Drops

Electrolyte blends or trace mineral drops are an easy way to quickly add elements like copper, manganese, selenium, iron and of course calcium and magnesium into your drinking water. These blends aren’t too expensive and available at every well sorted supermarket.

But beware: Some blends have a more balanced mineral composition than others.

sea saltMineral-Rich Sea Salt

Another inexpensive way to meet your daily nutritional requirements is to add a knife point of a mineral-rich salt, such as Himalayan Salt, to each gallon of filtered water. Don’t worry, it won’t taste salty. Himalaya Salt can provide you with more than 60 different trace elements.

Attention: A processed and inferior table salt, which contains almost only sodium and chloride is not sufficient.

Alkaline Water Filter Pitcher

Alkaline water filter pitchers will re-filter the water before adding calcium, magnesium and other minerals back into it and thereby balancing pH-levels. Of course a pitcher is more expensive than Himalayan Salt or electrolyte blends, but they last much longer and retail for about $40.

green powder blendGreens Blends

Greens blends are derived from vegetables, grasses, herbs and more and contain minerals, fiber and also vitamins. They are not to everybody’s taste, but provide an all-round solution to remineralize your body especially after you’ve worked out.

Unfortunately, greens blends that come in powder form are costly and therefore no long-term solution for most people on a budget.

Your Turn

You now know about the key points of demineralization and have also learned how to add minerals back into ro water. It’s your turn to make up your mind and decide what you are going to do. If remineralization is important to you, there are 5 possible solutions you can choose from.

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About the Author

My name is Derek, 28, and I am an advocate for the protection of nature and the environment due to a very selfish reason: I want my family, friends and myself to stay healthy. Quote: "There are no compromises when it comes to drinking water quality."

Leave a Reply 6 comments

Deepak Bagul - June 14, 2019 Reply

Very much thankful for the great and valuable information, Regards Deepak Bagul

Farida - August 11, 2019 Reply

Very good information shared.
I like the Himalaya salt method easily available and also easy to use in busy life style..

Farrukh - September 22, 2019 Reply

“Another inexpensive way to meet your daily nutritional requirements is to add a knife point of a mineral-rich sea salt, such as Himalayan Salt, to each gallon of filtered water. ”
Dear my question is that is the Himalayan Salt a type of sea salt? Or you mean to say that it is as good as sea salt?
Secondly, in terms if grammage, how many grams of Himalayan salt be added to a liter of RO water.
Thank you.

    Derek - October 9, 2019 Reply

    You are absolutely right, it is not. I edited the paragraph.

    I don’t know how many grams that is.

Mickey - December 6, 2019 Reply

I stayed at an ashram in new Zealand once and they had a water cooler which had layers of different rocks and pebbles in with the water… I’m wondering if this would also be an effective way of getting minerals back into drinking water??

    Derek - December 10, 2019 Reply

    It could be, depending on what these rocks and pebbles were…

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