well, if the tank was stocked to the limit with guppies, i doubt many of the fry will make it anyways. there will be guppies almost everywhere the fry go, and most of them will probably be eaten unless you have alot of plants and other hiding spaces. if there were less guppies, more of the fry would probably make it and then overpopulation would happen that way...so pretty much, i think overpopulation would happen faster in a less-stocked tank. of course, either way...i think overpopulation of guppies is almost unavoidable. does this make sense, or am i just crazy?