Member of the Month: May 2009, Oct 2010, Sept 2017
If it had been me, I would have filled those containers more than halfway. Unless my intention was to bury the stems when the plants got tall enough to stick above the tops of said containers, I suppose. Also, are you planning to kill all except for the healthiest of those five seedlings? Because, if not, you might want to consider separating them before their root systems intertwine.