Mine were fed with fry powder and ground down granules. They survived fine. Some do green water and live food. I try to add the moss, leaves especially floating plants in the hope these have small tasty items. I also think floating beneath a very bright light isn't like their natural birth environment. Mine usually buzzed about under the leaves. I kept them in there for 7-14 days and then added them to my shrimp tank. My experience has actually been that the fry were relatively easy, but the corys I raised have stayed smaller than the ones I brought, and I think it's the juvenile period that's crucial. They may have lacked live food, or some suggest they need to learn to eat by being with adults. Mine are all healthy, but like wee Scottish Picts, not tall Amazonians.