convicts , guppies, mollies, platys, other cichlids are all really easy to breed. The problem with breeding for feeders is the growth rate. It will take a few months for fry to get to a usable size of around 1''+. And if you breed some and then wait it out for a few months until they are all used up then you get maybe 2 weeks worth of food every 2-3 months. The best way to go about it is to have a breeding set-up of several tanks. Like 5 10g tanks with convict pairs in them. The when all there fry are a week or 2 old transfer them into a 30g tank. And wait a month and then transfer that into a 55g tank and feed from that. So that you have a running amount of feeders. All in all you will find out that it is not worth doing. And return to buying them shortly.