Purified Water vs Distilled Water vs Tap Water: Complete Guide to Water Types

Understanding the differences between purified water, distilled water, and regular tap water can help you make informed decisions about your daily hydration. Each type of water undergoes different treatment processes and offers unique benefits and considerations for your health.

Water is fundamental to human health, comprising about 60% of your body weight and playing crucial roles in nearly every bodily function. With various water options available in stores and from your tap, knowing which type best suits your needs is increasingly important.

This comprehensive guide explores what purified water is, how it compares to distilled and tap water, and whether these different water types are beneficial for your health.

What Is Purified Water?

Purified water refers to water that has undergone filtration or processing to remove impurities, contaminants, and unwanted substances. The purification process can start with water from various sources, including municipal tap water, groundwater, or surface water.

The key defining characteristic of purified water is that it meets specific purity standards set by regulatory bodies. In the United States, the Environmental Protection Agency (EPA) and Food and Drug Administration (FDA) establish guidelines for what constitutes purified water.

What Gets Removed During Water Purification?

Water purification processes are designed to eliminate various contaminants, including:

• Bacterial organisms and pathogens
• Parasites such as giardia and cryptosporidium
• Fungi and algae
• Heavy metals including lead, mercury, and copper
• Chemical contaminants and pollutants
• Sediment and particulate matter
• Chlorine and chloramines
• Pesticides and herbicides

Common Purification Methods

Several techniques are used to purify water, either individually or in combination:

Activated Carbon Filtration: This method uses carbon filters to absorb organic compounds, chlorine, and chemicals that affect taste and odor. Carbon filters are effective but may not remove all types of contaminants.

Reverse Osmosis: Water is forced through a semipermeable membrane that blocks contaminants while allowing water molecules to pass through. This method removes up to 99% of dissolved solids, including minerals, salts, and metals.

Ion Exchange: This process replaces harmful ions in water with harmless ones, effectively removing heavy metals and softening hard water.

Ultraviolet (UV) Treatment: UV light kills microorganisms by damaging their DNA, making it particularly effective against bacteria and viruses.

Ozonation: Ozone gas is bubbled through water to disinfect and remove organic compounds without leaving chemical residues.

What Is Distilled Water?

Distilled water is actually a specific type of purified water created through the distillation process. This method involves boiling water until it becomes steam, then collecting and condensing that steam back into liquid form in a separate container.

The Distillation Process

During distillation, water is heated to its boiling point (212°F or 100°C). As the water evaporates into steam, contaminants with higher boiling points are left behind in the original container. The steam rises, moves through a cooling system, and condenses back into pure water.

This process is highly effective at removing:

• Heavy metals
• Minerals (both beneficial and harmful)
• Bacteria and viruses
• Organic compounds
• Chemical contaminants
• Fluoride

Distilled water typically achieves 99.9% purity, making it one of the purest forms of water available.

Is Purified Water the Same as Distilled Water?

No, purified water and distilled water are not identical, though distilled water is a type of purified water.

The main difference lies in the purification method and the final mineral content:

Purified Water: Can be produced through various methods (reverse osmosis, carbon filtration, UV treatment, etc.). Depending on the purification method, it may retain some beneficial minerals.

Distilled Water: Produced exclusively through distillation. It contains virtually no minerals, dissolved solids, or contaminants, making it the purest but also the most mineral-deficient option.

Think of it this way: all distilled water is purified water, but not all purified water is distilled water.

Understanding Regular Tap Water

Tap water, also called municipal water, comes from public water systems that treat water from rivers, lakes, reservoirs, or underground aquifers before distributing it to homes and businesses.

How Tap Water Is Treated

Public water systems use multiple treatment stages:

Coagulation and Flocculation: Chemicals with positive charges are added to water, binding with negatively charged particles to form larger clumps called floc.

Sedimentation: Heavy floc particles settle to the bottom, separating from cleaner water above.

Filtration: Water passes through multiple filter layers (sand, gravel, charcoal) that remove remaining particles and microorganisms.

Disinfection: Chlorine, chloramine, or other disinfectants are added to kill remaining pathogens and maintain water safety through the distribution system.

Tap Water Safety Standards

In the United States, the Safe Drinking Water Act requires the EPA to set and enforce standards for drinking water quality. Public water systems must regularly test for over 90 contaminants and maintain levels below established maximums.

However, tap water quality can vary significantly based on:

• Geographic location
• Source water quality
• Age and condition of treatment facilities
• Distribution system infrastructure
• Local regulatory standards

Is Purified Water Good for You?

Purified water offers several health benefits, particularly in areas where tap water quality is questionable or for individuals with specific health concerns.

Health Benefits of Purified Water

Reduced Contaminant Exposure: Purification removes or significantly reduces harmful substances that may be present in tap water, including heavy metals, pesticides, and industrial chemicals.

Better Taste and Odor: Removing chlorine and organic compounds improves water’s taste and smell, encouraging increased water consumption and better hydration.

Protection for Vulnerable Populations: People with compromised immune systems, including those undergoing chemotherapy, living with HIV/AIDS, or recovering from transplant surgery, benefit from the reduced pathogen risk in purified water.

Reduced Chemical Exposure: Some studies have suggested potential links between long-term chlorine exposure and certain health risks, though more research is needed. Purification removes these chemicals.

Consistency: Purified bottled water offers consistent quality regardless of location, which is beneficial when traveling.

Potential Drawbacks of Purified Water

Mineral Removal: Some purification methods, particularly reverse osmosis and distillation, remove beneficial minerals like calcium and magnesium. While water isn’t a primary mineral source for most people, these minerals do contribute to daily intake.

Fluoride Removal: Many purification systems remove fluoride, which is added to public water supplies to prevent tooth decay. This may increase cavity risk, especially in children.

Cost Considerations: Home purification systems require initial investment and ongoing maintenance. Bottled purified water is more expensive than tap water over time.

Environmental Impact: Bottled water contributes to plastic waste. Home systems generate waste through filter replacements.

Maintenance Requirements: Filtration systems need regular filter changes and cleaning to remain effective. Neglected systems can become contamination sources.

Can You Drink Purified Water Every Day?

Yes, you can safely drink purified water daily. For most healthy individuals consuming a balanced diet, drinking purified water poses no health risks.

However, consider these factors:

Dietary Mineral Intake: Ensure you’re getting adequate minerals from food sources if drinking highly purified water that removes minerals. A varied diet typically provides sufficient minerals regardless of water type.

Dental Health: If your purified water lacks fluoride, maintain good oral hygiene practices and consider discussing fluoride supplementation with your dentist, especially for children.

Individual Health Needs: People with specific health conditions should consult healthcare providers about optimal water choices.

Distilled Water vs Purified Water: Which Is Better?

The choice between distilled and other forms of purified water depends on your specific needs and circumstances.

When Distilled Water May Be Preferable

• Medical uses and medical devices (CPAP machines, humidifiers)
• Laboratory applications requiring maximum purity
• Individuals with severe immune system compromise
• Areas with heavily contaminated water sources
• Situations requiring water with no mineral content

When Other Purified Water May Be Better

• Daily drinking and cooking
• When you want to retain some beneficial minerals
• For children and pregnant women who benefit from minerals and fluoride
• When seeking a balance between purity and mineral content
• For more economical and sustainable options

Comparing Key Characteristics

Purity Level: Distilled water wins for maximum purity (99.9%), while other purified water methods vary (typically 95-99%).

Mineral Content: Other purification methods may retain beneficial minerals; distilled water contains virtually none.

Taste: Many people find distilled water flat or bland due to lack of minerals. Other purified water often tastes better.

Cost: Distillation systems are often more expensive than other home purification options. Distilled bottled water typically costs more than other purified water.

Energy Use: Distillation requires significant energy for boiling. Other methods generally use less energy.

What’s the Difference Between Purified Water and Distilled Water?

To summarize the key distinctions:

Production Method:

• Purified water: Multiple possible methods (filtration, reverse osmosis, UV treatment, etc.)
• Distilled water: Only produced through distillation (boiling and condensation)

Purity Standards:

• Purified water: Must meet EPA or FDA standards for contaminant removal
• Distilled water: Achieves higher purity (99.9%) due to distillation process

Mineral Content:

• Purified water: May contain trace minerals depending on purification method
• Distilled water: Essentially mineral-free

Common Uses:

• Purified water: Drinking, cooking, general household use
• Distilled water: Medical equipment, laboratories, specific dietary needs, household appliances

Choosing the Right Water for Your Home

Selecting the best water type for your household depends on several factors:

Assess Your Tap Water Quality

Start by understanding what’s in your current tap water. You can:

• Request a water quality report from your municipal water provider (they’re required to provide this annually)
• Purchase a home water testing kit
• Hire a certified laboratory to test your water
• Check the EPA’s Consumer Confidence Reports database

Consider Your Household Needs

Think about:

• Household size and daily water consumption
• Presence of individuals with compromised immune systems
• Children who would benefit from fluoridated water
• Budget for initial investment and ongoing costs
• Available space for filtration systems
• Taste preferences

Home Water Purification Options

Pitcher Filters: Affordable, portable, easy to use. Best for basic filtration needs. Typically use activated carbon. Cost: $20-50 plus filter replacements.

Faucet-Mounted Filters: Attach directly to faucets for convenient filtered water. Moderate filtration capability. Cost: $30-80 plus filter replacements.

Under-Sink Systems: Installed beneath kitchen sinks, offering high-capacity filtration without countertop clutter. Various technologies available. Cost: $150-500 plus installation and maintenance.

Reverse Osmosis Systems: Comprehensive filtration removing most contaminants. Requires installation and produces wastewater. Cost: $200-600 plus installation.

Whole-House Systems: Treat all water entering your home. Most expensive but most comprehensive. Cost: $1,000-5,000 plus installation.

Distillation Units: Produce distilled water at home. Slow process, uses electricity. Cost: $100-300 for countertop units.

Maintenance Requirements

All home purification systems require maintenance to function properly:

• Replace filters according to manufacturer schedules (typically every 2-6 months)
• Clean system components regularly
• Monitor system performance and water taste
• Keep records of maintenance dates
• Budget for replacement filters and parts

Neglected filters can become breeding grounds for bacteria and actually contaminate your water rather than purify it.

When Tap Water Is Sufficient

Despite the marketing around bottled and purified water, tap water is safe and healthy for most people in developed countries with regulated water systems.

Tap water may be your best choice if:

• Your local water quality reports show compliance with all safety standards
• You haven’t noticed taste or odor problems
• No one in your household has immune system compromise
• You want the most economical and environmentally friendly option
• Your water contains appropriate fluoride levels for dental health

Tap water also contains minerals that contribute to daily intake of calcium, magnesium, and other essential elements.

Environmental Considerations

Your water choice has environmental implications worth considering:

Bottled Water Impact

Bottled purified or distilled water contributes to:

• Plastic pollution (millions of bottles end up in landfills and oceans)
• Carbon emissions from production and transportation
• Resource depletion (water extraction impacts local ecosystems)
• Energy consumption in manufacturing

Home Purification Impact

Home systems are generally more environmentally friendly but still involve:

• Filter disposal (cartridges aren’t always recyclable)
• Energy use (especially for reverse osmosis and distillation)
• Water waste (reverse osmosis systems discharge 3-4 gallons for every gallon purified)

Tap Water Impact

Drinking tap water has the lowest environmental footprint:

• No plastic waste
• Minimal energy use beyond municipal treatment
• No transportation emissions
• Shared infrastructure reduces per-person impact

Special Considerations for Specific Groups

Infants and Children

For preparing infant formula, consult your pediatrician. Some recommend distilled or purified water to avoid contaminants and control mineral intake, while others approve properly treated tap water.

Children benefit from fluoridated water for dental health. If using purification methods that remove fluoride, discuss fluoride supplementation with your child’s dentist.

Pregnant Women

Pregnant women should be especially cautious about water contaminants, particularly lead and certain chemicals. If tap water quality is questionable, purified water offers extra protection during this vulnerable period.

Immunocompromised Individuals

People with weakened immune systems from HIV/AIDS, cancer treatment, organ transplants, or certain medications should consult their healthcare providers about water safety. Distilled or highly purified water may be recommended to minimize infection risk.

Older Adults

Elderly individuals may benefit from mineral-containing water due to reduced dietary intake and decreased absorption efficiency. Overly purified water that removes all minerals may not be ideal unless diet provides adequate minerals.

Cost Comparison: Making the Economic Choice

Understanding the long-term costs helps in making an informed decision:

Tap Water

Average cost: $0.004 per gallon or less. For a family drinking 5 gallons weekly: approximately $1 annually.

Bottled Purified Water

Average cost: $1-2 per gallon. For the same family: $260-520 annually.

Home Filtration Systems

Initial cost: $50-500 depending on system. Annual filter replacement: $50-200. First-year cost: $100-700. Subsequent years: $50-200.

Distilled Water (Store-bought)

Average cost: $1-1.50 per gallon. Annual cost for same family: $260-390.

Home Distillation

Initial cost: $100-300. Electricity cost: approximately $50-100 annually. First-year cost: $150-400. Subsequent years: $50-100 plus occasional maintenance.

The Bottom Line: Which Water Should You Choose?

There’s no single “best” water for everyone. Your ideal choice depends on your specific situation:

Choose tap water if: Your local water meets safety standards, tastes good, and you want the most economical and environmentally friendly option.

Choose purified water (non-distilled) if: You want extra assurance about water quality, prefer better taste, or live in areas with questionable tap water while still getting some beneficial minerals.

Choose distilled water if: You have specific medical needs, require maximum purity, or your doctor recommends it for health conditions.

Choose a home purification system if: You want consistent, long-term access to purified water at a lower cost than buying bottled water.

Remember that regardless of water type, the most important factor is drinking enough water daily. The average adult needs 8-12 cups of water daily from all sources, though individual needs vary based on activity level, climate, and health status.

If you’re unsure about your tap water quality or which purification method suits your needs, consider having your water tested and consulting with healthcare providers about your individual circumstances. They can help you make an informed decision based on your health status, local water quality, and personal needs.

Ultimately, staying properly hydrated with safe, clean water—whether from the tap, purified, or distilled sources—is what matters most for maintaining optimal health.

Sources:

• U.S. Environmental Protection Agency – Drinking Water
• Centers for Disease Control and Prevention – Public Water Systems
• World Health Organization – Drinking Water Fact Sheet
• U.S. Food and Drug Administration – Bottled Water Information
• National Institutes of Health – Water Treatment and Purification
• NSF International – Water Quality Information
• Mayo Clinic – Water: How Much Should You Drink Every Day