I have 9 breeding females and run a 1.3 ratio in a 6 tub rack and 4 for breeders and 2 for grow outs separated by sex my rats usually reach large size by the time they are 6-7 weeks 3 of the breeder tubs are for the harems and one breeder tub is for the males when I remove them from the females after litters are starting to be born and they go back with females 2 weeks after weaning so you wouldn't necessarily have to have 2 racks if you only need a few per month I serve 25-30 rats per month but I am also stocking up for my december 2013 switch gassing my current breeders and bringing in new ones we also have a few friends that buy our extras anything above that or over 1 full month stock in the freezer goes to the local nature center. another thing you need to consider is rather you feed f/t or live, if you feed f/t a co2 chamber is a good investment it only cost me aprox 60$ to get mine setup and a air fill is like 3$ I can gas 20-30 rats at a shot twice a month before needing a refill on a 20oz bottle






