Actually, forget the trip to Walmart...just snagged a 5 pack of them
with my Discover Rewards Points ($1:$1 on Amazon). I wish I would've invented these things...holy cow. So simple yet so ingenious!
As far as foreground/carpet plants are concerned, I can either do HC, Glosso, or Elatine hydropiper. Keep in mind that it'll be intermingled with Riccia and DHG Belem.