i would be feeding them small pieces of shrimp, krill, silversides, tilapia, some bloodworms, and a good quality flake food. now is the time to get them eating whatever you want them to eat in the future, as they get bigger, they will become much more stubborn when it comes to new foods. you are really going to want to get them on pellets in the future, so you can also try dropping a couple pellets in there, they may be too small to eat them right now, but they can pick at them and get a taste for them now, just make sure you pull out whatever they don't eat after a bit so you don't foul up the water.
i would also suggest getting that 55 gallon ready pretty quick, if they are an inch long right now, you can expect them to be around three inches by the end of may, so the sooner you get them into a bigger tank, the better.
just make sure you keep your temps around 80f, keep up with weekly waterchanges, and make sure you keep a close eye on the little guys and you should be just fine. if you have any other specific questions, be sure to ask.