not to long ago i started a culture of grindal / white worms for same purpose, my medium to large fish eat red wigglers too. soon i wanna culture scuds,confused beetle, microworms, been kinda at odds of growing some RCS, or freshwater ghost shrimps as food. but the problem i'm having is to feed such a valueable critter as rcs for food production when they have the value they do as pets.