Reverse osmosis is one of the most popular ways to treat water at home.
Reverse osmosis filters have become more common as more people have become aware of all the potential lurking hiding in their water, including chemicals, heavy metals, and microbes.
Though they are more expensive than carbon water filters, many people are willing to spend more money to enjoy the high contaminant removal rate RO systems provide.
However, despite its better filtration performance, some homeowners (and apartment dwellers and RV/boat owners) are wary about drinking reverse osmosis water.
What could be so dangerous about drinking purified water? After all, most of the dangerous stuff has been filtered out.
It mostly has to do with minerals, or the lack thereof. Because RO water doesn’t contain any minerals, both good and bad, there are concerns that it might not be so good for the body.
In this article, we discuss the most common health and safety claims regarding reverse osmosis water and whether they warrant any concern.
But here’s our bottom-line: reverse osmosis water is safe and healthy for most people. Only a small subset of people – such as those with mineral deficiencies –needs to exercise some caution with RO water.
Claim: Reverse Osmosis Water is ‘Dead’ Since it is Demineralized
You may have heard reverse osmosis water described as ‘dead.’ The claim is that since the reverse osmosis process strips all the useful minerals from water, it is ‘dead’ nutritionally.
It is true that the semi-permeable membrane in an RO system doesn’t discriminate between good and bad minerals.
Useful minerals like copper, zinc, and magnesium as well as toxic ones like arsenic and lead are all filtered out.
But describing RO water as ‘dead’ is a bit of a stretch.
For one, most tap water isn’t that mineral-rich either. It doesn’t contribute a significant amount of minerals to your diet.
According to one report tap water provides more than 1% of the daily recommended intake for just four minerals: calcium, magnesium, sodium, and copper.
As long as you are eating a balanced diet, it doesn’t matter what kind of water you are drinking as long as it is free of harmful contaminants. Your diet provides virtually all your mineral needs.
By drinking reverse osmosis water, there is minimal risk of experiencing mineral deficiencies.
If you are still worried about not getting enough of healthy minerals, look for a reverse osmosis system that has a remineralization filter. It adds back healthy minerals (usually calcium and magnesium) to the RO water after it has passed through the membrane.
Alternatively, add mineral concentrates directly to your drinking water.
Claim: Reverse Osmosis Water is Acidic, Making it Unhealthy
When water is stripped of mineral ions, the pH drops. So sometimes, demineralized reverse osmosis water can be slightly acidic.
Some experts claim that this is bad for your body and that the acidic water can corrode pipes and leach contaminants like lead.
Indeed, acidic water is not very good for you. It can cause dental problems, worsen acid reflux, and leach dangerous metals into the water supply.
But RO water is not nearly acidic enough to cause such problems.
In fact, depending on the initial pH of your water and whether your system has a mineral filter, the resulting RO water can have neutral or alkaline pH.
You can do a pH test yourself using some pH strips. For accurate readings, use a pH meter. You’ll likely get a pH between 6 and 7. At most, it’ll be around 5-6.
In any case, the water will revert to a normal pH once you drink it, and it interacts with food in your stomach.
But if you don’t want even slightly acidic water, get a re-mineralizing RO system. It’ll produce purified mineral water with a pH between 7 and 8.
You can also add minerals directly to your drinking water to raise pH.
Claim: Reverse Osmosis Water Reduces Mineral Content in Food
This one is actually true. Cooking with demineralized water can lead to significant loses in mineral content in food.
Your food can lose up to 60% calcium, 66% copper, and 70% manganese.
Our recommendation: Do not use reverse osmosis water for cooking unless it has been re-mineralized.
Claim: Reverse Osmosis Water Will Cause My Kid’s Teeth to Decay Because it has no Fluoride
One of the chemicals removed during reverse osmosis is fluoride, which is added to the water in most cities to prevent tooth decay.
Some parents worry that by giving their kids fluoride-free RO water or using RO water to prepare formula, they risk tooth decay.
We recommend discussing this with your dentist or pediatrician.
But generally, for older kids, their main source of fluoride in toothpaste. If they use non-fluoridated toothpaste, ask your dentist if it’s necessary to give them water treated with fluoride.
If you prefer the drink RO water, your dentists may recommend fluoride drops or supplements.
For infants, however, it’s perfectly okay to use RO water for drinking and in baby formula. Children under 3 years need very little to no fluoride to keep their teeth healthy.
Infants less than 6 months old don’t need any fluoride at all since they have no teeth. In fact, they can suffer from fluorosis, a permanent discoloration of teeth caused by too much fluoride.
Claim: Reverse Osmosis Water Leeches Minerals from the Body
This claim is not based on any genuine study or research. It’s simply not true. Drinking reverse osmosis water will not cause minerals already in your body to leech out.
Benefits of Drinking Reverse Osmosis Water
For most people, the many benefits of reverse osmosis water outweigh the concerns. A reverse osmosis filter is the best way to protect your family from contaminants in water.
Here are some of the most significant benefits.
Chemicals like chlorine and hydrogen sulfide in water pose little to no health risk. But they affect the taste and smell of water.
A reverse osmosis system filters out chlorine, chloramines, VOCs, and any other chemicals that give water an unusual taste or smell.
It also gets rid of the metallic and rotten egg taste that’s common in well water.
If your main issue with your tap or well water is the smell or taste, a reverse osmosis filter will help. And it’ll cost you less compared to buying packs of bottled water every week.
No Heavy Metals
Heavy metals like lead and mercury are some of the most harmful water contaminants. Even minute amounts of these impurities can have adverse health effects, especially on children.
Reverse osmosis is the only filtration method that guarantees almost 100% removal of heavy metals from water (distillation is also effective, but it’s technically not a filtration method).
With kids across the United States (not just Flint) facing exposure to high levels of lead, you should be cautious about drinking tap water without treating it or at least having it tested.
No Waterborne Microbes
Chlorine or chloramines added to municipal water kills most of the bacteria and viruses in water.
If you want an extra line of defense against microbes like E. Coli, an RO system is a great choice. It traps bacteria, viruses, cysts, and other potentially harmful biologicals.
If you use untreated groundwater, installing a reverse osmosis system is even more important. It provides an easy way to access safe drinking water for your whole family.
Chlorine does a great job killing bacteria and viruses. But it doesn’t neutralize harmful chemicals such as pharmaceuticals, pesticides, herbicides, and VOCs.
These come from industrial pollution, agricultural runoffs, and other sources.
The activated carbon filters and the semi-permeable membrane in an RO system do a great job removing most of these chemicals.
Our Bottom Line
As I mentioned at the beginning, a reverse osmosis system is an excellent choice for most people and families.
It’s the best and most affordable way to guarantee safe drinking water at home.
RO systems used to be reasonably pricey a while back, but they’ve gotten cheaper. You can now get a good quality 5-stage reverse osmosis system for under $200.
Even the premium ones with a remineralization filter rarely cost over $300.
So if it’s the cost you are worried about, there are plenty of pocket-friendly options to choose from.
Remember that the effectiveness of reverse osmosis will vary among different models. Be careful when shopping for a new RO filter to make sure you choose the right one for your needs.
In our RO filter buying guide, we review and compare the best RO systems in the market from well-known brands like iSpring, Home Master, and APEC. It’s a great starting point for anyone looking to buy a reverse osmosis filter.