Most of the spawning survive, you always get the odd one that does not make it to the feeding stage for some reason but at that size you cannot tell if they are good or not.

The main culling happens at around three weeks old, this is just for deformed fish, i.e. bent backs one eye no eyes!!! etc. With nacreous (calico) fish you get a few pinks and greens these are removed as soon as you can tell colour in the fish. All others are kept and grown on, badly finned fish but healthy are sold to pet shops. (pinks are normally weaker fish and never last to any sort of age, the greens are much more robust but who wants a green fish that never changes colour and just blends into the backgound?