What is a reverse osmosis system, and how does it work?

A reverse osmosis system is an advanced water purification technology that utilizes a semi-permeable membrane to remove contaminants. It works by forcing water under pressure through this membrane, leaving behind impurities such as heavy metals, chlorine, pesticides, bacteria, and dissolved salts. The result? Clean, great-tasting water that’s free from harmful substances.

Many modern RO systems also include pre-filters (such as sediment and carbon filters) and post-filters (such as activated carbon or remineralization filters) to enhance the water's quality further.

Myth 1: Reverse osmosis water is "too pure" to drink

Some people claim that reverse osmosis water is dangerously pure – that it contains no minerals and therefore is unhealthy or even “hungry” to pull minerals from your body. This fear is unfounded. Leading health sources (like the CDC) explicitly state that claims about RO water being unsafe are false.

The reality is that drinking water is never a major source of dietary minerals. The human body absorbs most nutrients from food, not tap water. As one expert summary notes, “water alone does not contain enough minerals to provide nutrition” – even a mineral-rich drinking water has far less calcium and magnesium than a typical meal.

In practice, no well-documented health problems have arisen from drinking properly treated RO water in healthy people. Instead, RO systems ensure the water you drink is free of contaminants.

Myth 2: Reverse osmosis water causes mineral deficiency

Because RO removes minerals, some worry that drinking only RO water will cause calcium, magnesium, or other mineral deficiencies over time. While it’s true that RO removes virtually all dissolved minerals from water, this generally isn’t a concern for nutrition.

Numerous sources emphasize that most dietary minerals come from food, not water. For example, vegetables, grains, and dairy contain vastly more calcium and magnesium per serving than a liter of water. One analysis points out that drinking 7 ounces of orange juice supplies as much calcium as drinking 30 gallons of water.

Moreover, the mineral loss in RO water is typically minimal in context. Modern diets and supplements easily provide the recommended levels of essential minerals. As one Glacier Fresh guide notes, “the loss of minerals [in filtered water] is minimal, and a balanced diet should easily cover the difference.” Even if you drink mostly RO water, a healthy diet will supply all the calcium, magnesium, and potassium your body needs.

Myth 3: Reverse osmosis systems waste too much water

Reverse osmosis is often criticized for “wasting” a significant amount of water – some claim that RO discards 4–6 gallons of water for every 1 gallon it purifies. Traditional RO filters indeed generate a reject stream of concentrated brine; however, modern systems have significantly improved efficiency.

According to the U.S. EPA, a typical (older) under-sink RO system might produce on the order of 5 or more gallons of reject water for every gallon of clean water. However, high-efficiency models (such as WaterSense-certified units) achieve much lower waste. In fact, certified systems are required to maintain a ratio of 2.3 gallons of waste per 1 gallon produced or less.

In practical terms, even standard units often contain around four parts waste for every 1 part pure water. Furthermore, the “waste” stream is not truly wasted. It is simply water that has washed away the filtered-out impurities. That water can be repurposed for non-drinking uses, such as watering plants, rinsing floors, washing cars, or flushing toilets.

Myth 4: Reverse osmosis removes beneficial pH and makes water "acidic"

Some claim that RO water is so purified that it becomes acidic (low pH), and that drinking it will harm your body’s acid-base balance. Reverse osmosis water does tend to have a slightly lower pH than ordinary tap water, but the effect is minor and harmless.

Most tap water has a pH level of around 7.5–8.5 due to the presence of dissolved minerals and carbon dioxide. When RO removes those minerals, the pH can drop to around 6.0–6.5, which is only mildly acidic. Crucially, this pH level is still within the safe drinking-water range. The EPA’s voluntary guideline for water pH is approximately 6.5 to 8.5, and RO-filtered water typically falls near the lower end of this range. For comparison, common beverages like coffee, soda or fruit juices have pH well below 6; a pH of 6 is far less acidic than those drinks.

In summary, RO water may be slightly below pH 7, but it is by no means dangerously acidic. The slight drop in pH is simply a result of removing minerals, and it remains within drinking standards.

Myth 5: Bottled water is safer than reverse osmosis water

Many people believe bottled water is purer or safer than home RO water, so they buy bottled instead of installing a filter. In reality, this is often not true – bottled water is not inherently safer than a properly filtered supply. Most bottled water brands use RO, distillation, or carbon filtering in their process.

Many market-label bottles are filtered municipal water. Studies and industry sources note that a home reverse-osmosis system can produce water just as clean as bottled water. Home RO water also has a major environmental and cost advantage. Every year, the U.S. uses billions of plastic bottles and millions of barrels of oil to produce bottled water, far exceeding the amount of water that RO systems waste. By contrast, a single under-sink RO system runs on house water and electricity, creating virtually no plastic waste. Glacier Fresh customers find that an RO system pays for itself within months compared to buying bottled water.

Bottled water is not categorically safer, and often it’s the same filtered water you could get at home. Installing a home RO unit yields equal (or better) purity with far less plastic and cost.

Who can benefit most from reverse osmosis water?

In summary, reverse osmosis systems are ideal for anyone seeking extra assurance of water purity. In particular, reverse osmosis is especially recommended for:

· Homes with poor or untested water sources. If you draw water from a private well or live in an area with aging pipes or known contaminants (such as lead, nitrates, industrial chemicals, or PFAS), an reverse osmosis system adds a crucial safety layer.

· Vulnerable individuals and families. Pregnant women, infants, young children, the elderly, or immunocompromised persons benefit from the extra purity. These groups are more susceptible to even low levels of contaminants, such as lead or bacteria.

· Consumers who want great-tasting, reliable water. Anyone frustrated by tap water taste (chlorine, sulfur, hardness) will appreciate RO’s clean flavor. It’s also ideal for cooking or brewing coffee/tea, where pure water lets food flavors shine.

Conclusion

There’s a lot of misinformation about RO filtration, but the data are clear: reverse osmosis systems do not make water unsafe or nutritionally deficient. They remove unwanted substances, yielding very pure water that is entirely safe to drink.

The common “myths” (over-purification, nutrient loss, excessive waste, acidity, etc.) all have straightforward answers backed by experts and evidence. For the concerned consumer, the bottom line is this: drink clean water with confidence. A high-quality RO system from Glacier Fresh or another reputable brand will provide you with reliably pure, great-tasting water, without the fears peddled by myths. Cite the science, trust your filters, and enjoy safe hydration every day.