I have fry and when I saw this title I was like, "Holy Cow, You can over feed fry!?!?!"
I have mine in a breeder net within my 30G. I "overfeed" them, but the remains settle ot the bottom and what the other fish don't peck away threw the net (God, my gouramis are such glutons!), I syphon out with a turkey tube-thingy
EDIT: Oh yeah, I have 13 guppy fry and feed them a pinch of crushed flakes 2x a day and pinch of 'baby fry food' made by Tetra 2x a day.