I am very curious to see if anyone has ever done tobi once a day instead of twice? I notice if i only do it once per day rather than the recommended twice a day dosage, i get way less shortness of breath associated with Tobi. My last Dr. didnt have a problem with it and said doing it once a day is better than not doing it at all, but my newer Dr. does not agree with this at all. He says it is better to not do it at all.... if all i will do is once a day. I personally feel as though doing it once a day is beneficial because a lot of times if i am having hemoptysis problems i will start using the Tobi and just about every time it goes away with the once a day dosage. But if i start using it twice a day i start getting some shortness of breath within a few days.