If the line is a 50 foot line on your concentrator, you do need to increase the liter level. Thus the shorter the o2 line is, the more it can benefit you. I do not like takes, they have put me in more trouble than I can shake a stick at. "If," you're only useing 1 - 2 liters max, the tank will maybe give you 1 - 2 hours of o2, "but," if you need 3 or more liters, I've had it were I ran out of o2 in just a 1/2 hour of less. So that means always having extra tanks to drag around with you, because you can't just plug them in to recharge them like you can a concentrator. I hard wired my a.c./dc inverter, straight to my battery, I can run my home concentrator in my car, that means I have endless o2 at any liter from 1 - 6. I also have a very small portable concentrator, that goes as high as 5 liters of o2, and it to I charge in my car, out side the car I can go 4 hrs at 2 liters, 2 1/2 - 3 hours at 4 liters. And no more dragging them takes around. Opens up a new way of life for me.
God bless, breath deep !

I thought the concentrator would give better amount of oxygen. But I guess not. Did you have them check it? I had one that was putting out less oxygen they said 93% so they gave me another one.

is the concentrator the liquid I do better on it than my cylinder and sometimes neither seem not to be working

Liquid oxygen is 100% pure oxygen.
If the tanks you were using were filled with liquid oxygen that makes sence.
A concentrator is 94% to 96% oxygen.
That is running at peak potential,,,,,
Just thrown in my penny’s worth,,,,, hehee
Rapp

I used liquid oxygen for 11 yrs, my company dropped me . I now use a concentrated, like you I can't keep my level up as well. So yes bottles are good as long as you use pulsating you'll run out quick on continus.