Distilled vs. purified water

[CorruptAlligator]

I use purified water and no sign of build-ups after prolonged usage. Distilled is over-rated.

[Melman]

For those concerned about inhaling aerosolized chlorinated tap water you should avoid showers because a shower generates a great deal of aerosol which you inhale. Even if there's a very slight aerosol generation from your CPAP it's probably much less in a year than you inhale in a single shower. In other words, there's no reason for concern.

[DaveCar]

Allow me to get silly on this.
Can we use coffee ? raspberry flavoured vitamin water ?
If only the 'water' is evaporating and entering us, there should be a whole long list of things we can use.
I'll admit that Ive long since forgotten the science behind it, but somehow I feel that some 'things' can also travel in that evaporated liquid.
I wont use my well water.
I wouldnt use city water unless an emerg
I do use distilled water, the cheapest I can find (generally speaking, thats the W)
Odd that I trust that production, but not city waterworks .. lol

[Sleeprider]

Dave, interesting idea using coffee. It would work as far as evaporating water from the coffee and any aromatic volatile compounds, but the suspended and dissolved solids would be left in the humidifier chamber. Distilled alcohol would also work to deliver alcohol vapor. Might make things interesting until the liquid evaporated.

[Dog Slobber]

Allow me to get silly on this.
Can we use coffee ?  raspberry flavoured vitamin water ?
If only the 'water' is evaporating and entering us,  there should be a whole long list of things we can use.
I'll admit that Ive long since forgotten the science behind it, but somehow I feel that some 'things' can also travel in that evaporated liquid.

The process of creating distilled water is almost identical to the humidification process that occurs in our CPAP machines.

To create distilled water:

• heat the water 
  
• capture the humidity 
  
• the solids (and pathogens) do not evaporate and are to large to use the vapour as a vehicle
  
• other gases can evaporate, this is why many distilling processes use double or fractional distillation, distilling at various temperatures to separate different types of gasses
  
• capture the condensed vapour
  
• voila, distilled water
  
• optional, run a sanitising agent (often ozone) through the distilled product, this is done to ensure that any pre-existing pathogens in the tanks don't contaminate the distilled water
  

What happens in our CPAP machines:

• heat the water
  
• capture the humidity
  
• for the same reasons that solids and pathogens do not enter the distilled water capturing process, solids and pathogens can't enter our CPAP hose
  
• sometimes the humidity condenses back into liquid (rain-out), this water is distilled
  
• other gases or (gas products) that might be within the water, could enter the cpap system. This is why we should only use water that is safe to drink and not pond sludge
  

As described, the only real difference is the temperature used for commercial distilling. This is for the separation of gasses but mostly to speed up the process from days to minutes.

Now this is where some might start screaming, "BUT THE CHLORINE AND FLUORIDES, THEY'RE GAS AND THEY'RE TOXIC, THE GOVERNMENT IS CULLING US". Yes, both, if they were present in our tap water at sufficient levels, would be present in our CPAP humidification. Chlorine is typically added at 4 parts per million at the source, well below harmful levels and is long since gone before it hits our taps. Fluorides are still present but less than 1 PPM and also well below harmful levels. 

Anybody who is concerned about chlorine, fluorides or any other dissolved trace gasses, in our tap water, should be more concerned about showering in it. More gases would be released and breathed while showering. The aeration process releases dissolved gasses in water., and aerosolized water particles are also much larger than that derived from relatively still evaporation.

I would be cautious about putting well-water in my cpap tank and if I lived in an area where the tap water has so much minerals that cleaning was a chore, I would use distilled. Non-distilled water has primarily been used in CPAP since the inception of humidity and is still primarily used in most non-North American markets.

But the amount of people running around touting tap water as inherently unsafe in CPAP devices are wrong. They don't understand what distilled truly is, and their fear-mongering causes others needless stress, expense, inconvenance and even CPAP or Humidification avoidance when traveling or distilled unavailability.

[Sleepster]

The store i buy my distilled water has not had any in stock for several weeks. Instead they started selling “purified” water.

Likely it's the same water, the only change is in the laws regulating labeling. The water that we buy in those gallon jugs for about a dollar is for "distilled water use" but it is not actually distilled water, if it were it would be much more expensive. Europeans, for example, have to go to a drug store and pay what we Americans would consider an outrageous amount.

They likely filter the water using reverse osmosis (RO), but they probably also filter it through carbon.

I have a whole-house sediment filter and a water softener and also a RO filter in the kitchen. I just used the (softened) tap water in my CPAP chamber. I'd use the RO water but I'm too lazy to walk all the way to the kitchen.

It just doesn't matter that much. If you can drink the water safely, you can use it in your CPAP chamber safely.

[jpthuot03]

I appreciate this thread, as I've been quietly worried about not using distilled water. What I've been doing is running tap water through a Brita then boiling it. Sounds like maybe even that is overkill?

[Melman]

The filtration is probably good if it minimizes mineral deposits but the boiling is overkill. You inhale more unboiled tap water from the aerosol in a shower than you ever will from your CPAP humidifier.

[mesenteria]

Your tap water is safe to drink. It must also be safe to inhale as a vapour where it leaves any dissolved mineral salts behind. What you inhale is actually purer than what you drink.

[plymaniac]

I bought a cheap water distiller on Amazon so I didn't have to rely on commercial supplies.

But tap water is fine if you don't mind dealing with hard water deposits occasionally.