What’s the Difference Between RO and Distilled Water? Find Out Here

Understanding Two Paths to Pure Water

Both reverse osmosis (RO) and distillation produce highly purified water, but through fundamentally different processes. RO uses pressure and a semi-permeable membrane, while distillation involves boiling and condensation. These methods create water with distinct characteristics suited for specific applications.

Production Process: How Each Water Is Made

Reverse Osmosis Water Production:

• Process: Multi-stage filtration including sediment, carbon, and RO membrane
• Pore Size: 0.0001 micron membrane blocks contaminants
• Efficiency: 95-99% contaminant removal
• Wastewater: Produces some concentrate water (modern systems: 1:1 ratio)
• Speed: Continuous production, no waiting period

Distilled Water Production:

• Process: Boiling, vaporization, and condensation
• Method: Contaminants left behind as water evaporates
• Purity: Near 100% contaminant-free
• Energy: High energy consumption for boiling
• Time: Batch process, slower production

Mineral Content & Taste Profile

RO Water Characteristics:

• Mineral Content: Removes 95-99% of minerals
• TDS Level: Typically 10-50 ppm
• Taste Profile: Clean, neutral, slightly flat (can be remineralized)
• pH Level: Slightly acidic (6.0-6.5 typically)
• Customization: Remineralization filters available

Distilled Water Characteristics:

• Mineral Content: Virtually 100% mineral-free
• TDS Level: 0-5 ppm
• Taste Profile: Very flat, described as "lifeless" by many
• pH Level: Neutral (7.0) but becomes acidic when exposed to air
• Stability: Absorbs CO₂ from air, lowering pH

Drinking Water Comparison

Health Considerations:

RO Water for Drinking:

• Mineral Balance: Can be remineralized for optimal health benefits
• Hydration: Excellent absorption with proper mineralization
• Safety: Removes contaminants while allowing beneficial mineral addition
• Cost: Typically ranges from a few cents per gallon after system purchase, depending on local water rates and usage.

Distilled Water for Drinking:

• Purity: Maximum contaminant removal
• Mineral Concern: Lacks beneficial calcium, magnesium
• Long-term Use: May lead to mineral depletion if exclusive source
• Cost: $0.50-$1.50 per gallon store-bought, $0.25-$0.50 home-distilled

Taste Test Results:

• Blind Preference: a majority of participants prefer properly mineralized RO water
• Coffee/Tea Tests: RO water consistently scores higher
• Mixing with Flavors: RO water better preserves delicate tastes
• Temperature Effect: Distilled water tastes flatter when cold

Cooking & Food Preparation Applications

Cooking Performance:

RO Water Advantages:

• Vegetable Cooking: Preserves color and texture better
• Pasta & Grains: Cooks more evenly, better texture
• Soups & Stocks: Cleaner flavors, no chlorine interference
• Baking: Consistent results, better yeast activation
• Ice Making: Clearer ice, slower melting

Distilled Water Uses:

• Baby Formula: Recommended by some pediatricians
• Medical Diets: For specific sodium-restricted regimens
• Laboratory Cooking: When absolute purity is required
• Canning & Preserving: Prevents mineral deposits in jars

Flavor Impact Analysis:

• Tea Brewing: RO water (remineralized) scores often receives higher marks higher in taste tests
• Coffee Extraction: RO water achieves optimal extraction (18-22%)
• Sauce Reduction: Distilled water can create overly concentrated flavors
• Bread Making: RO water produces better crust and crumb structure

Appliance Compatibility & Protection

Home Appliance Performance:

For Steam Irons & Humidifiers:

• RO Water: Good choice with regular cleaning
• Distilled Water: Recommended by most manufacturers
• Mineral Buildup: Both prevent scale, but distilled is optimal
• Cost Analysis: RO system more economical long-term

For Aquariums & Hydroponics:

• RO Water: Preferred, allows custom mineralization
• Distilled Water: Too pure, requires extensive remineralization
• pH Stability: RO water more stable when properly treated
• Biological Systems: RO water better for supporting life

For Automotive & Battery Use:

• Distilled Water: Required for lead-acid batteries
• RO Water: May contain trace minerals affecting performance
• Radiator Use: Both acceptable, distilled preferred for sensitive systems
• Manufacturer Recommendations: Check specific requirements

Cost Analysis & Practical Considerations

Initial Investment:

• RO System: $300-$800 installed
• Distillation Unit: $200-$1,200
• Professional Installation: RO often requires plumbing, distillation needs electrical

Operating Costs:

• RO System: $100-$200 annual filter replacements
• Distillation: $150-$400 annual energy costs
• Water Waste: RO produces wastewater, distillation doesn't
• Production Rate: RO: 50-100 gallons daily, Distillation: 5-20 gallons daily

Space Requirements:

• RO Systems: Under-sink or basement installation
• Distillation Units: Countertop or dedicated space needed
• Storage: Both require pure water storage solutions
• Footprint: Similar space requirements for equivalent capacity

Environmental Impact Comparison

Energy Consumption:

• RO Systems: 0.3-0.5 kWh per 100 gallons
• Distillation: 3-5 kWh per 100 gallons
• Efficiency: RO uses 85-90% less energy

Water Usage:

• RO Systems: 1-4 gallons wastewater per gallon purified
• Distillation: No wastewater, but high energy water equivalent
• Overall Impact: RO has lower environmental footprint with modern efficient systems

Plastic Waste:

• Home Systems: Both eliminate bottled water purchases
• Manufacturing Impact: Similar material requirements
• Long-term Waste: RO filter replacements vs. distillation coil cleaning

Safety & Contaminant Removal

Effectiveness Against Specific Contaminants:

Heavy Metals:

• RO Removal: 95-99% of lead, arsenic, mercury
• Distillation Removal: 99.9%+ of all heavy metals
• Practical Difference: Both provide safe levels for drinking

Microorganisms:

• RO Removal: 99.9%+ bacteria and viruses
• Distillation Removal: 100% when properly operated
• Real-world Safety: Both exceed EPA drinking water standards

Volatile Organic Compounds (VOCs):

• RO Removal: 95-99% with carbon pre-filtration
• Distillation Risk: Some VOCs can evaporate and recondense
• Solution: Both systems require carbon filtration for VOC removal

Making the Right Choice for Your Home

Choose RO Water When:

• ✓ You want balanced mineral content
• ✓ Energy efficiency is important
• ✓ Higher production volume needed
• ✓ Cooking and drinking are primary uses
• ✓ Cost-effectiveness is a priority

Choose Distilled Water When:

• ✓ Absolute purity is required
• ✓ Medical needs dictate mineral-free water
• ✓ Specific appliances require distilled
• ✓ Small quantities needed occasionally
• ✓ You can accept higher energy costs

Ideal Combination Approach:

• Primary System: RO for general household use
• Supplementary: Small distiller for specific needs
• Cost-effective: RO for 95% of needs, distilled for special applications
• Flexible: Best of both worlds approach

Maintenance & Long-term Care

RO System Maintenance:

• Filter Changes: Every 6-12 months
• Membrane Replacement: Every 2-5 years
• Sanitization: Annual recommended
• Monitoring: TDS meter checks monthly

Distillation Unit Maintenance:

• Cleaning: Weekly to monthly depending on use
• Descaling: Regular removal of mineral deposits
• Component Replacement: Heating elements, condensers
• Monitoring: Production rate and purity checks

Expert Recommendations

From Water Quality Specialists:

• General Households: RO systems recommended for most families
• Medical Applications: Consult healthcare provider first
• Taste Preferences: Try both before deciding
• Environmental Consideration: RO has smaller carbon footprint

From Appliance Manufacturers:

• Check Manuals: Specific requirements vary
• Warranty Considerations: Using recommended water types
• Performance: Both protect against scale when properly used
• Longevity: Proper water extends appliance life