Use alfalfa pellets, not rabbit pellet. Not only is it cheaper, it has no copper, which rabbit pellets are loaded with. Primary feed is the pellets. Suppliment about 20% with high protein sinking pellets.

Get the walkamins, they grow faster and get bigger. For a breeding colony you can put 1 male and 4 females in a 20 gallon tank with hides for each cray.