Just had them, second batch. First batch became free swimming, but died. Take 2. They are still wrigglers. When they start swimming/hovering, is that when I feed? And is just egg yolk adequate?
From what i understood when i was reading about breeding, was start feeding when the yoke is gone its has sufficient nutrients in it to keep the fry going. Search a bit about making your own fry food very very cheaply done and very effective.
After mine became free swimming, I moved them to a small (2 gallon) tank with heater and sponge filter only tank. I fed them fresh brine 3 times a day, did a water change after each feeding............that was five years ago, and I still have one of them. Good luck, it's lots of fun!