Not really, most predators that would be big enough to eat convict fry would need a larger tank. Just remember bigger fish eat littler fish. A bigger fish also needs a bigger tank. Me personally when I bred convicts I fed em to my oscars, giant gourami, Jaguar and Jack Dempsey's all of which are far too big to be in anything less then a 80g on its own. The giant gourami would need atleast 150g to its self. I mainly fed the convict to my bearded dragon (Ed) tho, he used to love the lil 1in fish as snacks.
Kind of, guppies and danio's aren't all that predator tho so you may end up with a bunch of baby convicts secretly living with your other fish. Even when I fed em to my predator fish I still always had some that would survive. Some even made it to breeding age in that tank.
Oh! And near is a relative term depending on tank size could be whole tank half or a third......
. I will check if they have convicts.