Too be honest, if you're going to be running 30 colony's of 1.5 you should just make a 80 bin birthing rack or 2 40 bin racks. You also have to remember you're going to be producing 2000+ rats a month. You're going to have to get a bunch more grow out bins if you're going to go all out with this project. I would suggest at least another 20 bins just for grow out.