Hmmm...
Based on just these handful of responses, it begs the question: "Is it possible for a normal person, who barely has time to eat and sleep, to devote enough time to participate in this hobby ?" As a followup: "just how much time is necessary ?" Just something rhetorical to ponder...

Now, back to the question,
I tell myself at least twice a week but end up lucky to get one, using 3 tanks at a time. I'm just starting out and have lots of enthusiasm and still have trouble finding time. Oh well, if I could ever get the right parts and not have them fail rigth away it might be better.