Hi again MLaen,
just two guidelines:
a) In pranayama (except Kapalabhati, Bhastrika
or Ujjayi) the premise is to breath silently. In the moment you hear your breathing, you're doing it wrong
b) Another thing: There's a pranayama concept named 'breath length' which means at which distance vertically from your nose you stop noticing
your breath. So a long (strong) breath will be felt maybe (you can use a wet hand or a mirror) at 30 cm down your nose. One of the goals of pranayama
(linked with the previous guideline) is to shorten this length at espiration. So you cannot exhale
in a short manner if you inhale was to "strong"
So you must breathe silently,short (in strength) and long in time. The pattern you mention (5:0:10) is indicated to relax the mind, as you know the longer the exhale, the more relaxation you attain, as in exhalations heartbeat slows down and in inhalation heart rate goes up (you can experiment this in very loooong breaths) , so you must breath smooth and from the belly.... No need to fill the whole lungs. It's only needed
to fill the whole lungs in a pattern with retention
(second time different than zero) or in an exciting pattern (inhale longer than exhale: kapalaphati or
bhastrika)
Hope that helps,
Oscar