In my molly only tank, the mollies ignore the fry for the most part. I do have one female molly that will eat fry. So I put her in a different tank that has guppys, gouramis and platys in it. I have a paradise fish in another tank that takes care of most of my molly fry. Some survive but most disappear. It might sound cruel and my wife was not happy with the idea of the "babies" getting eaten but once I was over run with over 100 fry, she understood that some times you just have to let nature take its course. Please don't write me nasty messages about this. I feel it's much crueler to keep 100 fry in a 10 gallon tank than it is to let the fittist survive.