I have tried numerous times with Reidi. Unfortunately I was just never able to get the fry to survive very long. As fry rearing is very labor-intensive (and costly), I gave up on the palegic fry (ie: Reidi and northern Erectus) and now concentrate on the Southern Erectus and dwarfs.
As Teresa mentioned, Reidi fry need rotifers as their first food. You will need to start rotifer culture tanks (minimum of 2 in case one crashes) as well as live algae cultures. Due to their feeding requirements and palegic nature, Reidi fry require much more of a time/money investment than I care to spend again at the moment.
On a side note, you may have misinterpreted something you read. When one has limited time/money/experience it is best to concentrate your fry rearing effort on only the strongest fry. Not randomly scooping out just a few after birth, but rather after a few days, those that are swimming strongly, eating well, etc should be the ones all your efforts are directed at. The remaining weak swimmers, those floating at the top, laying on the bottom, not eating well, etc should be culled. Especially with large broods of fry, you could end up losing them all by trying to save them all. With smaller broods, or after culling, your success improves as all your time and effort is concentrated on the dozen or two strongest of the fry.
Tom