Running two groups or one group is the same amount of work. At
  my peak of group running (which was mailing lists but same
  idea), I was juggling a dozen or so active groups and the
  biggest problem I ran into was occasionally mixing one group up
  with another temporarily.

  If you run two groups simultaneously, you can test out whether
  or not:

  a) closed group = large + high quality
  or
  b) public group = large + high quality

  The one that fares less well, you can either close or pass on to
  someone else to run and you can focus on your core group.
  [1]Just now * [2]Like

References

  Visible links
  1. https://www.facebook.com/groups/EthicsAndMoralPhilosophyCouncil/permalink/918107011560498/?comment_id=918577671513432&offset=0&total_comments=54&comment_tracking=%7B%22tn%22%3A%22R%22%7D
  2. Like this comment
       https://www.facebook.com/groups/EthicsAndMoralPhilosophyCouncil/permalink/918107011560498/?comment_id=918573324847200&offset=0&total_comments=50&notif_t=group_comment_mention#