I left them in a breeding trap for just under 2 weeks, they was a reasonable size. About the size of my fingernail on my little finger. When they was born they were pretty much transparent, they were solid white and 1 was grey when I added them.
I tried to introduce the fry to the tank twice, first time was a frenzy. I just added them and all the fish went mental chasing them and the fry hid behind the filter so I took them all out.
2nd time I fed the fish about 30-40 mins before I added the fry, I also added some floating plants to the top of the tank so the fry had a safe spot to rest. I added the fish into the plants and the rest of the tank was none the wiser of the new arrivals, they hung out in the plants for about another week and would never leave each other. They come out further and further everyday until 1 of them swam across to the other side of the tank and the rest just followed, they all survived and they still never leave each others side.