@tconz. Just putting my 2 cents in... I used 7% Sod Chl with a past pulm doc. He would not say it was better than 3% but he was OK for me to use it--I tolerated it well. Two years later was referred to another pulm doc closer to home. He would just shake his head and smirk when I brought up the subject. "just don't think it makes a difference." I brought it up again with him today. He said the same thing again but is OK to write a Rx for 7%. We all learn from our doc's but also from each other. Blessings all.