One of the most common questions CPAP users still ask is surprisingly simple: “Do I really have to use distilled water in my CPAP?”
With newer machines, smarter humidifiers, and more people travelling with CPAP than ever before, it’s worth revisiting this topic. Let’s break it down in a clear, practical way so you can protect both your sleep and your equipment.
Why Water Choice Still Matters
Your CPAP humidifier plays a big role in comfort, helping prevent dryness, congestion, and irritation. But the type of water you use directly impacts the lifespan and cleanliness of your equipment.
Manufacturers like ResMed (AirSense 10, AirSense 11, AirCurve) and Philips continue to recommend distilled water to:
- Prevent mineral buildup
- Extend the life of the water chamber
- Reduce cleaning and maintenance issues
Bottom line: following the manufacturer’s guidelines is still the best way to ensure optimal performance.
The Main Types of Water You Might Use
1. Distilled Water (Best Choice)
Distilled water is created by boiling water into steam and then condensing it back into liquid. This process removes:
- Minerals (like calcium and magnesium)
- Microbes
- Chemicals and impurities
Why CPAP users love it:
- No mineral scale
- Less frequent cleaning
- Longer-lasting humidifier tubs
This remains the gold standard for CPAP humidifiers.
2. Spring Water (Use With Caution)
Spring water comes from natural underground sources and contains minerals picked up from rocks and soil.
While it may sound “pure,” it:
- Still contains minerals
- Can leave residue in your water chamber
Only use spring water if your CPAP manufacturer specifically allows it.
3. Tap Water (Emergency Only)
Tap water is treated for drinking but still contains:
- Minerals
- Chemicals like chlorine or fluoride
Over time, tap water can:
- Cause scaling and discoloration
- Shorten the lifespan of your humidifier chamber
- Require more frequent replacements
Water quality also varies by location, urban vs. rural areas can differ significantly. Occasional use won’t break your machine, but regular use is not recommended.
What Happens If You Don’t Use Distilled Water?
We’ve seen it many times: users who rely on tap water often need to replace their humidifier tubs more frequently due to mineral buildup.
If you do use non-distilled water:
- Clean your water chamber more often
- Monitor for cloudiness or white scale
- Replace the chamber according to the manufacturer’s schedule
What About CPAP Water When Travelling?
Travel adds another layer to the question.
Best practice when travelling:
- Buy distilled water from a pharmacy or grocery store when possible
- If water quality is questionable, don’t use it in your humidifier
Many users temporarily use bottled water only until distilled water is available.
Pro tip: If safe water isn’t accessible, it’s perfectly fine to turn off the humidifier and run your CPAP without water for a short period.
Final Thoughts
- Distilled water is still the best choice
- It protects your CPAP equipment and improves longevity
- When travelling, safety and water quality come first
- When in doubt, skip the humidifier temporarily
A small daily habit, choosing the right water can make a big difference in comfort, maintenance, and long-term costs.
Sleep smarter, sleep cleaner, and let your CPAP work the way it was designed to.
