I've used many foods when raising fry. Be it born from an egg or live born.
I've found a really good food is powdered cichlid pellets mixed with powdered flakes. I used a medicine mixer to get a fine powder as fine as flour.
This can be mixed into a liquid to be fed to egg hatched fry or fed in the powder form to liver born fry.
The growth rate with this mix was amazing. Molly fry grew to 1.5cm in a week or so.
Off-course, the pellets I used were a Local bulk type brand, repackaged by the LFS. The flake food was also a local brand called Marltons but I guess any good tropical flake food works.
You might be able to get faster growth with the trusted brands sold Globally.
Anyway. Fry will eat anything tiny enough. I read about green water but not so sure it's a healthy start for any fish.
Hope all goes well with your angelfish fry. My angels are apparently both females...I really wanted to get fry from them. :(