tank divider problem

I've decided when I get fish for my birthday(which is coming up) I will divide the tank of wild guppies too. here is my plan:
get a pregnant fancy guppy and have her give birth behind a divider. later, put the fry into the part with wild guppies so I can breed semi-fancy guppies in the future.(Please do not advise me that purbred guppies will make more money and that stuff because I am not selling them.)
But how do I put in a tank divider if my aquarium dosen't have substrate? and How much should I section off for one female guppy?

 

uh... can someone please say something?(This is a rephrased version of "bump")

 

please, can someone reply? does anyone know the answer?

 

How big is the tank? And if you don't care about the line why not just let them all be together?

 

it's Because I've learned from bad experience that when you throw a fancy guppy into a tank of wild ones, the fancy guppy will be attacked until it dies.

 

now I have another issue: the female guppy, if she stays behind the divider once she gives brith, she'll eat they fry. But if she goes on the other side, she'll be the one being eaten away. What do I do about that?

 

bump... no one's answered yet

 

Some dividers I've seen seemed to clip onto the sides of the tank.

Don't you think the wild guppies will eat the fry?

You could keep the fry in a breeder basket on either side to keep them away from the rest of the fish.