Fishy Medical Oxygen Concentrator, I just bought it. Swing the humidifier bottle down and it won't come down? Is it a hard twist by hand?

I don't know which oxygen concentrator you are using, but I know that fish leap 7F-3 and 7F-3L two models of the machine's humidification bottle is all hand-screwed down, screwed when you must hold the cap part, so as not to connect the humidification bottle of the tube is torn, screwed down after the water, be sure to tighten it, do not screw off the threads to each other tightly buttoned up, there is a little deviation, it will cause leakage of oxygen from the normal outlet place out of the oxygen. Normal from the oxygen outlet place out, so that is to use up to pay attention.