If you are trying to decide between distilled water and purified water, it is essential to understand the differences between them. Distilled and purified waters both can be beneficial in having a clean source of drinking water; however, they each have unique characteristics that make them special. In this article, we will explain what is the difference between distilled water and purified water so you can determine which one fits best into your lifestyle.
How Distillation and Purification Work?
To understand how distilled and purified water differ, it’s important to first outline the processes involved in creating each type of water.
Purified water goes through a multi-stage treatment process to remove contaminants and impurities while retaining naturally occurring minerals. The exact steps vary, but commonly involve:
- Pre-Filtration – Water passes through filters to remove particles, sediment, and larger contaminants.
- Carbon Filtration – Activated carbon filters absorb chemicals, pesticides, and other organic impurities.
- Deionization – Ion exchange resins remove dissolved salts, metals, and minerals by exchanging hydrogen and hydroxide ions for ionic contaminants.
- Reverse Osmosis – Water is forced through a semipermeable membrane that filters out viruses, bacteria, salts, and other molecules.
Purification aims to produce clean, safe drinking water while maintaining a balanced mineral profile. The resulting water has very low dissolved solids and neutral pH.
Distilled water is created by the process of distillation. This involves:
- Heating water to the boiling point, turning it into steam.
- As the steam rises, it passes through a condenser, which cools it back into a liquid form as distilled water.
- Impurities and minerals with higher boiling points remain behind.
Because nearly all impurities are removed, distilled water is very pure with extremely low mineral content. It also has a slightly acidic pH.
How Do They Compare for Your Health?
One of the biggest differences between purified and distilled water is mineral content, which can impact health in a few key ways:
- Electrolyte Balance – Minerals like calcium, magnesium, and potassium help regulate fluid balance and muscular function. Distilled water lacks these essential minerals.
- Toxic Metal Leaching – The lack of minerals in distilled water may also cause leaching of toxic metals like lead from distribution systems and containers.
- Heart Health – Hard water with higher calcium and magnesium levels may provide some protection against cardiovascular disease. Distillation removes these beneficial minerals.
- Digestion – Minerals play key roles in digestive processes. Long-term use of distilled water could negatively affect gut health and nutrient absorption.
However, for people with conditions like kidney stones or gout, distilled water may be recommended to reduce mineral intake from water. Those with excess lead exposure may also benefit from distilled water for reducing this toxin. For most people though, purified water with moderate mineral levels is ideal.
Evaluating the Environmental Impact
Both purification and distillation use more energy compared to basic filtration. However, distillation requires heating water to its boiling point, so it typically uses more electricity.
Reverse osmosis filtration also wastes 2-10 gallons of water for every purified gallon produced. Distillation has nearly 100% water recovery, giving it an advantage for conservation.
On the other hand, the transportation, packaging, and storage of distilled water in plastic bottles has a significant environmental footprint. Purification systems can produce water on demand at home or business, reducing waste and emissions from transport.
Overall, in-home purification systems tend to be the more eco-friendly choice over bottled distilled water. However, purification still uses substantial energy and water resources compared to other treatment methods.
Taste, Cost, and Other Practical Factors
Taste, cost, and accessibility also weigh into decisions between distilled and purified water. Key differences include:
- Taste – Purified water maintains some mineral content for a fresh, clean taste. Fully demineralized distilled water may taste flat or bland by comparison.
- Cost – Home distillers can be purchased for $200-500 but have high energy demands. Under-sink reverse osmosis systems start around $150, with lower operating costs.
- Convenience – Distillers require more hands-on time and maintenance. Purification systems run automatically with simple filter changes every 6-12 months.
- Accessibility – Distilled water must be produced on-site or purchased in stores. Purification systems deliver water on demand.
- Safety – Both methods remove microbial contaminants. But only distillation removes 100% of minerals and chemicals for highest purity.
For most households, an under-counter reverse osmosis system offers the best combination of affordability, convenience, and safety. However, travelers may prefer distilled water in portable containers for guaranteed purity.
Standards and Recommendations
The Environmental Protection Agency (EPA) sets legal standards for drinking water in the United States. For bottled purified water, the EPA requires:
- Zero E.coli or coliform bacteria per 100 mL sample
- Less than 10 ppm total dissolved solids
- No added fluoride, sweeteners, or flavors
The FDA also regulates bottled water and sets “good manufacturing practice” rules. However, they do not stipulate a maximum TDS level for purified water.
Distilled water must meet the EPA purified water guidelines. The FDA also requires it contains no more than 10 ppm TDS.
The World Health Organization recommends calcium levels between 10-100 mg/L and magnesium 10-50 mg/L in drinking water, which distilled water does not provide.
Overall, both purified and distilled water meet EPA safety standards when properly produced. But purified water is more aligned with WHO guidance for ideal mineral nutrition.
Applications Beyond Drinking
While this guide has focused on distilled and purified water for drinking, both have applications across many fields:
- Medical – Distilled water is used for sterilization, medical devices, and procedures. Purified water prepares pharmaceuticals.
- Laboratories – High purity distilled water is essential for experiments and analysis requiring water.
- Cosmetics – Purified water ensures quality and safety in cosmetics manufacturing.
- Food Production – Purified water sanitizes equipment and prevents food contamination.
- Automotive – Distilled or deionized water is used in vehicle cooling systems, wiper fluid, and batteries.
The choice depends on the level of purity and mineral content needed for the application. Cost and accessibility may also dictate which method makes sense for industrial use.
Alternatives Beyond Distillation and Purification
Distillation and purification are not the only methods for treating water. Some alternatives include:
- Ozonation – Ozone gas sterilizes and oxidizes contaminants without chemicals.
- Ultraviolet Irradiation – UV light disinfects microbes but does not remove minerals or chemicals.
- Ceramic Filtration – Porous ceramic effectively filters particulates, parasites, and bacteria.
- Activated Alumina – Alumina beads adsorb fluoride and arsenic from water.
These options involve lower cost and complexity compared to distillation or reverse osmosis. For residential use, activated carbon filtration is also an affordable option for improving water taste and safety.