I am going to a Respirologist. He specializes in breathing. Ask your GP Doctor to refer you to one, in your area. Mine is very very helpful. I started with him, because I was in the Hospital, starting with pneumonia.
I have a oxygen concentrator 25ft long. When I am sitting, it was on #2. I put it on #3 if doing chores. I have found that the #3 on the concentrator 25ft is so much weaker than on the 7ft tubing. It gets to me quicker than the other. Anyone else has found this to be true? Thank you.