To raise the fry, ok i'm only on my second batch, but here's what worked with the first.
The eggs will hatch within 5 days, probably less depending on temperature. The yolk sack will last for a day, probably no more, again depending on temperature. To feed the fish i started with liquifry no1 for a few days, then used bbs. They really don't take long to set up. I used sera sachets, which include the salt and eggs. Just add water, Literally! Hatch them in a 500 ml pop bottle, use just a piece of airline tubing to keep the eggs moving, within 24 hours you should be able to syphon off enough food for one of the daily feeds. Don't use too much or you'll pollute the water, certainly the bottom of the tank. I also use liquifry powder. Ideally when the fish have hatched you should feed three times a day, although at least twice if you can't make lunchtime. Also remember to make daily water changes, i change about 30% every day at the moment, it keeps the water fresh, and removes any harmful chemicals that might stunt the fishes growth. Yes it can be time consuming, but half the fun is raising the fish, they develop so quickly. Withing a week they've gone from little more than a small tadpole, to what is recogniseable as a cory it's remarkable.
Also a little tip, use a piece of airline tubing to suck out any detrius that accumilates on the bottom of the tank, particularly with cory's being bottom dwellers. put your thumb over one end to stop the water coming up it, drop ithe other end down to the dirt and release your thumb, the release of the air and the water pressure should suck the dirt into the tube. Also useful for removing small fry for observation or for if you want to clean the tank, but only for the first week, the fry will be too big after that.
