Like 35WINDOW I use the 75/25 CO2/Argon mix, and my regulator is also set for 15 CFH which is just a hair over 7 LPM (7.08). My regulator will back up to about 30 CFH trigger off, and then drop to the regulated 15 CFH with the trigger on. I also use the 0.030" wire, but I've always used Hobart/Miller wire because that's what's stocked at Tractor Supply and my welding supply shop.