Leak graph in Sleepyhead

I have a Respironics machine. My daily charts show two graphs (one green and one purple) corresponding to Leaks and total Leaks. On one night my "Leaks " range was 0-10 L/min (purple graph) and my Total Leaks was 0-64 L/min (green graph). I don't understand the difference. Can someone help?

Total leak is the mask's expected vent rate plus any excess leak.
Leak is a close approximation to excess leak only. It can't be 100% accurate because the machine doesn't know what mask you are using so it can't calculate an exact excess leak number because vent rates vary by mask and pressure...but it 's probably close enough for a good idea.

Respronics machine typically report Total Leak and Large leak territory is somewhere up around 80 to 90 L/min when reporting Total leak. We aren't ever told an exact number where Large leak begins but past history and experience have shown it to be around 80 to 90 L/min depending on machine and pressure used.
So generally I just say if you don't come close to large leak territory for very long it doesn't really matter because the machine can compensate for a good bit of excess leak.

All masks have a vent rate or intentional flow leak rate...listed on the paperwork. It varies between masks and with pressure...more pressure will increase the vent rate. This is included in the Total Leak reported....
if it is the bottom leak line that is the approximate excess only leak. We have no idea what number is the number to avoid when talking excess leak only with a Respronics machine. People assume that we would start with 0 baseline but people using higher pressures will have a higher baseline and not be at 0.0. I have seen Leak (as in excess only) leak reported as 20 L/min when using full face mask at 17 cm pressure and there was no excess leak at all.
For this reason I usually suggest that people learn to understand the top leak line which is Total leak and base their large leak territory to avoid on that number.