A curious observation.

[Big Guy]

I've been using the same CPAP machine in the same house since Sept. of 2018. We don't have a water filtration system in our house and I've been using tap water for the last 3 years or so in the water chamber. 

I've always had some slight mineral build-up deposits in the water chamber. Nothing really bad, just some slight build-up. I'm also using the same water chamber that came with my machine. I can't see discarding it when it works just fine. 

For the last 10-12 nights or so, I haven't had any mineral build-up to deal with. I always empty the water chamber each & every morning and wipe it dry with a paper towel. If it's bad enough, I've used White Vinegar and that quickly resolves any issues. 

As far as I know, the water quality hasn't changed any in our community. If by some chance it has, I'm not aware of it. 

Anyways, I'm kind of stumped as to why it's no longer being an issue. I could understand a couple of nights w/o build-up, but a week or more, it has me wondering. Like I said, it's now been at least over a week, maybe a week and a half, and no residue deposits. 

[G. Szabo]

I guess you have checked that your heating panel is operating correctly.

[Nightynite]

Maybe the water dept. stopped using fluoride. 

[Lucid]

Our water supplier changes additives with the seasons because temperature affects how well they work.  I believe they may have changed what they use over time, as well, as I am noticing so much more crud these days left behind wherever tap water evaporates.  Is it possible your supplier is trying something new?

BTW, I normally used distilled water in the tank, and only occasionally use tap water if I run out of distilled.  What I have found is that I don't have to use vinegar to remove the precipitate.  A night or two of distilled water alone will remove it.  Distilled water actually seems to work better than a vinegar solution, without the smell.  If I wanted to switch to tap water, I think I would just buy a jug of distilled water every now and then to get rid of the precipitate.

[Big Guy]

Our water supplier changes additives with the seasons because temperature affects how well they work.  I believe they may have changed what they use over time, as well, as I am noticing so much more crud these days left behind wherever tap water evaporates.  Is it possible your supplier is trying something new?

BTW, I normally used distilled water in the tank, and only occasionally use tap water if I run out of distilled.  What I have found is that I don't have to use vinegar to remove the precipitate.  A night or two of distilled water alone will remove it.  Distilled water actually seems to work better than a vinegar solution, without the smell.  If I wanted to switch to tap water, I think I would just buy a jug of distilled water every now and then to get rid of the precipitate.

I started out CPAP Therapy using distilled water. I did that for well over a year or so. But, I got tired of having to have it on hand, plus the cost added up over time. 

I saw some members were using tap water, so I thought, what the heck. The tap water was never really a big deal in regards to having to deal with some mineral build-up. That was easily dealt with. 

Anyways, it's just kind of odd that I don't seem to have as much mineral deposits as I used to. I'm keeping any eye on it and I'll see if it continues. 

[Sleeprider]

Don't hesitate to get a new humidifier tub. The newer style with the round heating plate is much easier to clean, mire efficient, and there is simply no point waiting until you have a leak, then need to wait for delivery. Most residue in tap water comes from calcium hardness that is used to prevent water from being "aggressive" and etching pipes. Water tends to be more aggressive at lower pH and hardness levels and cold water is more aggressive than warm water, so we often see plant operators increase calcium in winter, which seems counter to your observations. It's also possible that your water company has changed from something like sodium bisulfate (NaHSO4) to HCl for pH adjustment. Anyway, if you don't let the chamber go dry, there is usually no deposits.

[Big Guy]

Yes, I have extra water chambers on hand. No problem there! And, most of them have the updated round heating plate. 

Gonna give it a few more nights just to see if the deposits return. It's kind of like a murder mystery! I have to get to the bottom of it and know for sure. 

[Big Guy]

I went thru a full tank of water last night. Not even 1/2 of a teaspoon of water left. 

Zero deposits left behind.