Oxygen must be used as your doctor ordered it. Too much or too little can be harmful. Do not change the oxygen flow rate on your own this can lead to serious side effects. If you feel you are not getting enough oxygen, contact your physician and notify your home care supplier. Never use more than 50 feet of oxygen tubing. This can dilute the concentration of oxygen that you are receiving. Do not smoke or allow others to smoke in the same room as your oxygen system.