Is it easy to breed minnows?

I have 5 cichlids that enjoy chasing around minnows. Its becoming a hle to constantly go to the pet store to purchase minnows. (before you answer, i am aware that minnows have very little nutritional value for the cichlids but i like that they keep them active) I have my cichlids in a large tank of their own but i also have a 29 gallon tank in my game room. Im just wondering if breeding the minnows would be easy, what i would need to do for this to be successful (tank conditions), would the minnows eat the fry if i had alot in one tank, how many it would be okay to have in the tank in order to breed or if i should just keep the tank filled with them for easy access instead of always going to the pet store & just not worry about breeding???