Can you drink water from a water maker safely?

October 27, 2025 •

4 min read

According to manufacturers, a properly maintained reverse osmosis water maker can produce water that is often purer and safer than most tap water. So, can you drink water from a water maker? The answer is a definitive yes, provided you understand the technology and follow critical maintenance procedures for safety.

Quick Summary

Modern water makers use reverse osmosis to produce safe, potable water from seawater, but proper maintenance and regular use are crucial for safety. The final water quality is highly dependent on system upkeep and operating practices, ensuring it is free from contaminants.

Key Points

Reverse Osmosis (RO): Water makers use RO to force seawater through a semi-permeable membrane, filtering out salt and impurities to create fresh, potable water.
Requires Regular Maintenance: Safe operation depends on consistent flushing with freshwater, regular filter replacements, and proper storage procedures.
Monitor Water Quality: A salinity or TDS meter is essential for testing the product water to ensure it is within safe drinking parameters before it enters the storage tank.
Avoid Contaminated Water Sources: For best results and system longevity, operate the water maker in clean, open water and avoid polluted harbor areas.
Environmental and Cost Benefits: While initially costly, a water maker is a more eco-friendly option than bottled water and becomes more cost-effective over time, reducing plastic waste and reliance on shore supplies.
Don't Use Chlorine: Never use chlorinated water for flushing, as it can cause irreversible damage to the sensitive RO membranes.

Understanding the Water Maker Process

Water makers, also known as desalination systems, use reverse osmosis (RO) technology to purify seawater. The process works by applying high pressure to seawater, forcing it through a semi-permeable membrane. The membrane has pores so small that they allow water molecules to pass through but block larger ions like salt, as well as bacteria, viruses, and other impurities. The concentrated brine is discharged, while the pure freshwater is collected for use.

This multi-stage process ensures a high degree of purification. Initial pre-filters trap larger sediment and particles, protecting the sensitive RO membrane. Following the membrane, some systems add a post-treatment stage, such as an activated carbon filter or a UV sterilizer, to further improve taste and ensure biological safety. A salinity sensor or TDS (Total Dissolved Solids) meter continuously monitors the water quality, automatically diverting unsafe water away from the storage tanks.

The Importance of a Reliable Water Source

While water makers can create potable water from seawater, the quality of the input water still matters. Running a water maker in polluted harbor water or near a heavy-traffic area is not recommended, as pollutants like hydrocarbons can clog membranes and contaminate the system. Instead, it's best to operate the system in clean, open water to maximize efficiency and longevity. The cleaner the source water, the less strain on the pre-filters and the RO membrane, leading to more reliable and purer output. This practice significantly reduces the risk of contamination and prolongs the life of your equipment.

Critical Maintenance for Safe Water

Safe drinking water from a water maker is not a guarantee; it is a result of meticulous maintenance. Neglecting your system can lead to bacterial growth, compromised membranes, and ultimately, unsafe water. Here are the key maintenance steps:

Regular Flushing: The membranes must be flushed with freshwater after each use or at least weekly if not used daily. This prevents salt crystallization and organic growth from damaging the membrane. Some modern systems feature an automatic freshwater flush.
Use Non-Chlorinated Water: Never use chlorinated water (like most city dock water) to flush the system, as chlorine can permanently damage the RO membrane. Use the water produced by the water maker or run it through a carbon filter first.
Regular Filter Changes: Pre-filters are sacrificial components that need to be replaced regularly—typically every few months, depending on usage. Clogged filters reduce system pressure and efficiency, impacting overall water quality.
Seasonal Preservation (Pickling): For long-term storage, such as during the off-season, the system should be preserved with a special biocide or non-toxic antifreeze solution to prevent microbial growth.
Monitor Water Quality: Use the built-in salinity monitor and a handheld TDS meter to periodically test the product water. A rising TDS reading can indicate a problem with the membrane or a system leak.

Water Maker vs. Bottled Water: A Comparison


Feature	Water Maker (RO System)	Bottled Water
Convenience	On-demand water supply, no need to carry heavy bottles.	Requires frequent purchasing and transport.
Cost	High initial investment, but lower long-term cost per gallon.	Low initial cost per bottle, but expensive over time.
Environmental Impact	Significantly reduces plastic waste and carbon footprint from transport.	Major contributor to plastic pollution and transportation emissions.
Quality	Produces highly pure water, free of most contaminants, minerals, and additives.	Varies widely by brand; some contain microplastics and contaminants.
Maintenance	Requires regular flushing, filter changes, and membrane preservation.	Minimal maintenance, but large dispensers can harbor bacteria if not cleaned.

Different Types of Water Makers

Water makers come in various forms to suit different needs, from small survival kits to large-scale marine systems. The most common types rely on reverse osmosis but differ in their power source and energy efficiency.

Engine-Driven Water Makers: These systems use power from the vessel's main engine to operate, making them excellent for high-output needs and long passages.
High-Pressure Pump Water Makers: Often powered by AC generators, these systems can produce water quickly but are more energy-intensive.
Energy Recovery Water Makers: Utilizing a special pump (like the Clark pump), these units recover energy from the brine discharge to help pressurize incoming water, dramatically reducing power consumption and making them ideal for battery-powered vessels.
Manual Water Makers: Hand-pumped units, such as those from Katadyn, are used in liferafts and for emergencies, producing a limited but life-sustaining amount of water.

The Risks and How to Mitigate Them

While water makers offer a reliable source of fresh water, ignoring best practices introduces risks. Contaminated water can lead to health issues.

Biofilm Contamination: Microorganisms can grow on the membrane and internal system components if not flushed properly, leading to contamination of the final product water. Regular flushing is the best defense.
Improper Installation: Incorrect installation, such as placing the intake in a turbulent area or near engine exhaust, can introduce air or oil into the system, damaging the membranes. Follow manufacturer guidelines strictly.
Chemical Damage: Using chlorinated water or improper cleaning agents can destroy the delicate RO membrane. Always use specific, approved pickling and cleaning solutions.
Aging Components: Over time, membranes and seals can degrade, reducing filtering effectiveness. Routine monitoring of TDS levels and periodic component replacement are necessary.

Conclusion

In conclusion, you absolutely can drink water from a water maker safely, and doing so offers significant benefits in terms of self-sufficiency, convenience, and environmental impact. The key to ensuring safety and purity lies in a proper understanding of the reverse osmosis process and, most importantly, diligent maintenance. By regularly flushing the system, changing filters, and avoiding contaminants, a water maker becomes a dependable source of high-quality drinking water. The decision to install a water maker is an investment in both your independence and health, reducing reliance on bottled water and its associated waste.

For more technical information on marine water systems, consult resources from a trusted manufacturer like FCI Watermakers.

Frequently Asked Questions

Water makers use a process called reverse osmosis (RO). High pressure forces seawater through a fine, semi-permeable membrane that blocks salt ions and other impurities while allowing pure water molecules to pass through.

Yes, water produced by a modern, properly maintained water maker is safe to drink. The RO process effectively removes salts, bacteria, viruses, and most contaminants, resulting in high-purity water.

Regular flushing with fresh, non-chlorinated water is necessary to prevent salt crystallization and biological growth on the RO membrane, which can damage the system and compromise water quality over time.

A water maker, specifically for marine use, is a desalination system that removes salt and impurities from seawater using reverse osmosis. A water purifier typically refers to a system that treats freshwater to remove biological and chemical contaminants.

Modern water makers have a built-in salinity or Total Dissolved Solids (TDS) meter that monitors water quality. Always test the product water before directing it to your tanks to ensure it meets safe drinking standards (generally below 500 ppm).

It is generally not recommended to mix tank water produced by your water maker with dock water, as many municipal water sources contain chlorine, which can damage the RO membrane if used for flushing. Use a carbon filter if you must rely on dock water for flushing.

If left unused for an extended period, the RO membrane can degrade due to biological growth. Systems should be regularly flushed or, for long-term storage, pickled with a special biocide or preservative to protect the membranes.