I feed mine live baby brine shrimp! I bought this hatchery http://sanfranciscobaybrand.com/inde...mpery-kit.html
But then I drilled a hole in the top to put an air tube in. The only problem is a heater doesn't fit in it, so less shrimp hatch out. It also is a pain and spills ALL OVER, so I usually leave the little clear cup (that goes on top to collect BBS) off for the 1st day, and then turn off the pump and put the cup on. Also you can make your own hatchery, my baby betta LOVES his brine shrimp!!!