I'm about to start breeding rats to not just feed my snakes, but I would also like to supply a few friends with their feeders, and have enough left over to sell enough to at least break even. Which means I'm planning on undergoing a relatively large scale project here. Here's what I'm curious about:

1) I'm trying to figure out how many breeders I want. I know, in the beginning, I won't be making any money. My first thought was to get 20 mature females and 4 males. Which would obviously make my bins 1.5 (males to females). Does this sound appropriate? And on average, how many pups could this setup POTENTIALLY produce a week?

2) I'm going to build a nice rack for my rats. I'm curious of what other breeder's systems are as far as how they rotate their rats through their bins. Basically I'm trying to figure out how many bins I want. I was thinking about making a 12 bin rack with the large cement mixing tubs. With my current plans that will give me 4 bins for my breeders and 2 grow out bins for each colony. Again, does this sound appropriate?

I've got a good understanding of everything else I need to know. Created plans for a nice rack with a watering system. I'm just trying to get my numbers straight. I appreciate all of your help. And any other suggestions, if you have any, would be great!

Thanks for your help!