I have tried putting them all into a tank with mesh about 3" off the bottom and a layer of java moss but that didn't work out. Next I will be trying a bigger tank as the one I just tried was rather small for so many fish. Would not be surprised if they ate all the spawned eggs (assuming they spawned).
Its been suggested I use small groups of neons in a 10 gallon which is what I had the first time when it worked => May end up having to do it that way. I am buying some 2x4 material to build shelves so I can have more tanks but with my track record so far I dont have high hopes.
That said the first spawn I had 3 fry survive long enough to get their color. Watching them grow was interesting especially since I had them in a tank *full* of marbled crayfish =/ I don't know what I was thinking doing that. I put them in my neon tank a few days ago.
EDIT: lately time and lack of interest in this project has me doing other things but I have not given up.