Minimum pressure -- trying to understand the algorithm

[Pugsy]

The flow limitations are still likely the driving force behind the pressure but it looks like maybe the pressure wasn't so wild in its roaming. Hard to say for sure due to the scale in the others compared to last nights. Zoomed way in always looks wilder than not so much zoomed in. The making mountains out of mole hills thing due to scale involved.

Did you top off the water chamber and use it all or was it just not quite full and used it all.
These things should go at least 8 hours when full. Middle of the night having to add water is not acceptable even at max setting for humidity.

[cathyf]

The flow limitations are still likely the driving force behind the pressure but it looks like maybe the pressure wasn't so wild in its roaming. Hard to say for sure due to the scale in the others compared to last nights. Zoomed way in always looks wilder than not so much zoomed in. The making mountains out of mole hills thing due to scale involved.

Yeah, I squashed the graphs flatter to see a bunch next to each other. This is sort of interesting --

I zoomed in on the 1/2-hour after I went back to sleep at 11:15. Just matching up the flow limitations and snores vs the machine taking the pressures up and down, it looks like the ResMed algorithm is pretty sophisticated. Given that it is almost perfect at heading off my events, I'm pretty impressed.

Did you top off the water chamber and use it all or was it just not quite full and used it all.
These things should go at least 8 hours when full. Middle of the night having to add water is not acceptable even at max setting for humidity.

So far, I only have to fill the tank every 3-4 days -- we'll see how long it lasts when the outside temps are 20-below! I forgot to check before I went to sleep, and it occurred to me that maybe this was the reason I kept drooling and breaking the mask seal. That might have been a coincidence (it seemed intelligent at 2am, sounds stupid now ) but it did get me up and I fixed it.

[Pugsy]

I prefer maximum humidity and unless it is raining outside and I have the windows open my night routine is to always check the water level because I found out the hard way what my nose does when I run out of water for any length of time.
Water consumption varies with the ambient humidity in the bedroom air (leaks and pressures used will also impact water consumption).
So I always at least open the humidifier and check the water level to see how much was used the night before and unless there is a substantial amount left...I always top it off. I don't want to run out in the middle of the night...been there and done that and it wasn't pretty.

Murphy's law dictates that the one time I don't I will need more to get me through the night and for me it's more than the odor of hot plastic that is a problem...my nasal mucosa don't like being dried out at all and I pay for it the next 3 days with some nasty symptoms that make me feel miserable.
One hour of running dry isn't so bad but half the night and I pretty much pay for it in nasal symptoms for several days.

With time you will get a feel for water consumption but for now I would suggest checking the water levels daily and when in doubt...top it off. Anything that wakes us up is unwanted and water level checking takes only a second or two and in time becomes pretty much habit. Either in the AM or right at bedtime...I do it at night just because it is habit now.
Water (even distilled) is cheap and the price for fragmented sleep is much greater than saving a few cents on water.