The ULTIMATE method to clean your humidifier tank

Due to positive feedback from several people, I have started this dedicated thread regarding a method that works INCREDIBLY well to clean CPAP humidifier tanks. It uses common household items and NO harsh chemicals, but the results are amazing!

Background: Even when using distilled water, eventually a biofilm will develop on the interior surfaces of a CPAP humidifier tank. It may be so thin that it's not easily noticeable - but it is inevitable that it WILL form.

Biofilms are notoriously difficult to eliminate. They are comprised of a colony of bacteria in a matrix of a mucous-like slime. The slime acts as a physically protective barrier & adhesive, and it is very difficult to remove. This is the primary reason that humidifier tanks are replaced on a regular basis.

THE CLEANING METHOD:

1.) Put a few drops of dish soap inside with some water. Shake the humidifier to spread it to all interior surfaces. (The soap is a "wetting agent" and will help break the surface tension of the biofilm.)

2.) Rinse and drain the reservoir several times; you do not want any bubbles to form when it's agitated.

3.) Empty the reservoir and then add a several heaping tablespoons of salt. I use plain old table salt, but kosher or sea salt with big crystals should work too. (Iodized salt is not necessary, but it theoretically would act as an additional sanitizing agent.) Get a lot of salt in there, and then shake it all around to distribute & coat the salt on the interior surfaces.

4.) Add just enough water to make a very wet slurry. You don't want to dissolve the salt, you want to slosh a slurry of salt & water around and allow the salt crystals to act as an abrasive on the slime film. Shake it very vigorously for a minute. (The salt also acts to disrupt the bacterial cellular membranes due to high osmotic pressure differentials.)

5.) Let it sit for a minute or two, then shake it vigorously again. Then add some more water and shake it again. End by rinsing it several times, and... voila!

When I did this the first time, the tank was SERIOUSLY clean - like an absolutely brand new reservoir! And I mean like BRAND NEW - even the plastic was bright & clear!

NOTE: If you have NOT been using distilled water and there is a build up of minerals inside your tank, the biofilm slime can act as an insulator and inhibit your ability to chemically remove the mineral buildup by using an acid such as vinegar or a commercial product like C-L-R.

You could try my method to first remove the biofilm. Once the biofilm is removed, then any acidic liquids will be able to get to the mineral deposits and dissolve them.

(P.S. I am NOT advocating using any harsh chemicals, but it's a free country and you can do whatever you want in regards to removing any mineral deposits. I DO advocate using distilled water to avoid mineral buildup in the first place though.)

I hope that this is helpful, and I eagerly await your feedback after you try it!

An update...

A simplified, yet still extraordinarily effective method:

I just now tried skipping the soap. Instead, I simply emptied the reservoir, added a few tablespoons of rubbing alcohol and about 4 tablespoons of regular iodized table salt. (Again, the idea is to create a slurry that will be slightly abrasive against the surfaces when agitated.) I sloshed it around for about 90-120 seconds, rinsed thoroughly, and the reservoir looks like brand-sparkly new!

Again - I AM consistently using distilled water. However, after 4-6 weeks of use, a biofilm still develops on the bottom surface. It's relatively unnoticeable, but it's definitely there. (Everyone can test this themselves by simply rubbing the bottom of the reservoir with a finger. You will see that you have rubbed a film off - the metal will be "cleaner" where you rubbed it.) When you use the above method, there is NOTHING left on the surfaces whatsoever.

Happy pap'ing to everyone...

I don't think you are supposed to use rubbing alcohol in your reservoir. I would think it might ruin the plastic and if you don't rinse well breathing in rubbing alcohol cannot be hood. If you have to use something maybe white vinegar. Personally I use distiller water and rinse daily and my reservoir looks as good as new

Rubbing alcohol is not a good thing to consider inhaling.
Here is a link to an MSDS for one brand of rubbing alcohol.
http://www.sciencelab.com/msds.php?msdsId=9924412

However, since the mixture of alcohol and coarse salt seems to do the job of cleaning, perhaps using a really cheap vodka or grain alcohol for the alcohol would work and not harm the plastic or metal parts of the humidifier tank. The cost might be only twice that of the rubbing alcohol and be safe.

A couple of rinses with distilled water afterwards would remove all traces of the alcohol and/or salt from the tank. Wouldn't want to propose a means of getting sloshed while on CPAP after all.

How about baking soda and white vinegar? Plus it would be fun.

Serious suggestion, despite my interest in fun.

" . . . after 4-6 weeks of use, a biofilm still develops on the bottom surface."
I get the same interval with Dawn, plus tap water rinse, and using only home-distilled water.
Is the salt even doing anything?

I think the salt is acting like an abrasive that cuts into the biofilm and lets the other ingredients work.
If you slosh it around, it won't scratch the plastic.

Ummmmm..... Seriously.... who ever suggested inhaling any residual alcohol? That obviously wouldn't be good. Neither would inhaling the fumes from mixing bleach and ammonia. Duh. I simply rinse it several times with tap water, and then do a final rinse with distilled water. Then I go sniff some airplane glue and inhale some nitrous oxide.

As far as the alcohol degrading the plastic... again – seriously? We will all be biodegrading long before that plastic degrades significantly enough to affect it's clarity or structural integrity.

As for mixing vinegar with the salt, that may actually be very effective for anyone that doesn't use distilled water, as it will help dissolve any mineral buildup. However, for the chemically paranoid amongst us, the following should be noted:

The salt will dissolve in the vinegar, which is mostly water. But a chemical reaction will also occur with the vinegar's acetic acid (CH3COOH) and the ions of sodium and chlorine from the salt, producing sodium acetate and a dilute solution of hydrochloric acid. YIKES! Battery acid! Quick, run for your lives! Argghhhh..... The sky is falling!

Oh.... no.... wait a second. The sky's not falling. It's just a hallucination from inhaling all this stuff. My bad. Carry on...

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P.S. - Chunkyfrog: The salt serves two purposes. One, the osmatic pressure differential disrupts the cellular membranes. (Pop!) It also serves as a mild abrasive to help physically dislodge the sludge.

Geez, you are an ignorant one.

I agree that as long as you rinse reasonably well and let it sit a bit, the rubbing alcohol will probably not be a problem in terms of breathing it, unless it leaves a smell that bothers you. Even a lingering smell should go away pretty quickly. Many of us are exposed to fairly large quantities of rubbing alcohol on our skins when using it for various medical reasons.

As to whether alcohol will damage the tank, even if rinsed, it might stick or soak into the softer gasket materials and degrade them over time. I don't know if it's likely, but it's possible. On the Respironics tanks, if the bottom gasket leaks, it will leak water into the humidifier.

Remember that replacing a tank isn't that expensive if you do damage one somehow. Get a spare one and keep it on hand and you don't have to worry too much about damaging one. If you've got two, you can clean one and let it sit aside for a week or so to dry off and keep the germs down.

I wash my ResMed S9 dishwashable tanks in the dishwasher. I've even heated up a big pot of water, boiled the water, turned off the heat, and then dropped the disasembeled tank into the water and left it until it cooled. Note that's the S9 dishwashable tank. When I tried that with a standard S9 tank, the plastic sort of melted, so be sure you have the dishwashable tank, and I probably wouldn't do it even then unless I had a spare tank. You never know when they might change the material used and not tell you.

Alas, my ignorance knows no bounds. (Ignorance = a lack of information. ~ Stupidity = lack of ability to utilize information.) Yet I digress...

Archangle, as always, you bring up rational & salient points.

The cost to replace a humidifier tank IS low. (I merely seek to avoid an unnecessary cost in doing so.) Rotating a spare one makes sense too. (If you already possess more than one.)

The issue about any gaskets may *technically* be valid depending upon the material, but the overall effect will be negligible - especially considering that we aren't soaking it for a prolonged period of time. That would apply to *any* chemicals used, whether they be alcohol, vinegar, soap, urine, whatever.

Alcohol evaporates quickly, while vinegar will have a greater propensity for leaving some residual smell (as do soaps) - thus my choice of alcohol instead of vinegar. (Plus I used distilled water, so I don't have any limescale buildup.)

It is not my intention to create a debate about minutiae associated with cleaning ones' humidifier. I just wanted to share a technique that work EXTRAORDINARILY well. Over a period of time, I'd love for people to actually *try* this method - and then report back here with their results. That would keep the thread active for a long time and therefore help keep it towards the top of search results whenever a "newbie" comes here looking for advice.

ignorant1 wrote:It also serves as a mild abrasive to help physically dislodge the 'sludge'.

Wait! You really wouldn't want to do that. To physically dislodge the "sludge" might mean that he couldn't come here anymore; and if you read some of his knowledgeable posts (along with the other helpful things he does, that would be a real shame!

I only observed that my biofilm develops no faster while not using salt.

ems wrote:

ignorant1 wrote:It also serves as a mild abrasive to help physically dislodge the 'sludge'.

Wait! You really wouldn't want to do that. To physically dislodge the "sludge" might mean that he couldn't come here anymore; and if you read some of his knowledgeable posts (along with the other helpful things he does, that would be a real shame!

well, there's good sludge, and there's bad sludge

chunkyfrog wrote:I only observed that my biofilm develops no faster while not using salt.

it's not a preventative measure, it's a remediation measure.

palerider wrote:

chunkyfrog wrote:I only observed that my biofilm develops no faster while not using salt.

it's not a preventative measure, it's a remediation measure.

Ummmm.... yeah. The salt is only used for cleaning. You're not supposed to be trying to emulate a fresh ocean breeze by using salty water while using your xPAP. That wouldn't be advisable at all. (Please tell me you were being facetious.)