well, a female can have up to 30 eggs at one time, sometimes even more........but the # which hatch depend on the female(if she's stressed, too warm/too cold, etc.)........but u should get at least 10 each batch......so if no tank mates, u should see like 10 new babies each month(but they're tiny, like 2mm)........with tank mates, prob. like 3-5 a month