Suprize Fry...What to feed?

[cale262]

A couple weeks ago I emptied a 29g biocube of everything but the sand, rock rubble and water, I left the pump running and unplugged the heater skimmer and lights. Last night I went to shut it down and clean it, when I looked in the tank I saw about 50 small fry swimming around...the only pair I had in there were a couple clowns. I have never bothered keeping any fry in any of my other tanks as they usually became food once they started swimming, since there is no other occupants in this tank I may just try to grow out these guys but my big question is...

What should I feed these guys, I'm sure they are more than likely finnished (2wks) with their sacks?

TIA.