I have a peak flow meter. It is called " Personal Best peak flow meter" I LOVE that thing. I got it from my nurse at the cf clinic . What i do with it is........... at night i use my flutter first, then the peak flow meter. I keep a record in my mind what my averages are plus this thing also has little arrow markers you can use for your best and worst scores. When i use it after using the flutter it ALWAYS helps me cough out some crap. If i use it without using the flutter sometimes it helps me cough stuff out and sometimes not depending on how much is down in my lungs. Either way i am able to see when my numbers go down and its time for a change in treatment or medication. I also can see when things are going better as my numbers rise to normal after being sick. I know its not a foolproof way to guage things all the time, but it does give me piece of mind when im not feeling my best , but my numbers are steady, and it also helps me bring up some stuff that needs to come out. Me personally .... i would recommend it . It cant hurt and it may help ( with bringing stuff up) so why not? Just dont rely totally on it to give you an accurate measure of your lung status .