In my experience, there are three stages to aquaculture.
Stage one: Hatching the eggs.
Stage two: development from fry to juveniles.
Stage three: juvenile to adult.
Stage one was unexpectedly successful. After just three days, the carp eggs hatched, leaving me with easily one hundred baby carp, and very few unhatched eggs. For a day or so, the fry clung to the bottom or the sides of the aquarium, presumably feeding off the remaining yolk from their eggs.
However, stage two is by far the most difficult step. Once the fish are juveniles (basically miniature adults) they will eat whatever adult carp eat, provided it is in small enough pieces, but the fry can be very selective. Often they feed heavily on rotifers of a certain size, and finding a substitute for this wild fare can be very difficult.