It's around 8-9 days. Generally when you can see the sliver of their eyes, the next night they should hatch. I turn off the lights , pumps and circulation, wait about an hour, shine a flashlight and when they come to the light I siphon them up with a hose. Don't shine the light on the eggs or you'll have to wait till the next night. I've only got 1 batch out of the 120, Both my pairs are in a 20 with a divider now.