thanks Okie bipap and zonker, I increased the minimum pressure to 7. It's only been one night, but I put the graph below.
One shot, I know... I figured I'd try, and there were no problem.
I also turned off "pressure relief". It seems like it's easier to breathe without it? (disclaimer; i have little/no idea what I'm doing

)
by the way, my sleep lab report indicates AHI 3.1 and RDI 21.1 ! (dated dec 2017)
palerider;
yeah sorry, I didn't read everything, there is so much information on here (some outdated..). Just thought it'd be quicker to post and get feedback.
Your help and others' is *hugely* appreciated. I'm a newbie at this, and your wisdom is incredibly valuable. (my doc barely gives me the time of day... canadian healthcare

)
cheers!
