Breeding question

[Riv]

I currently use tanks to breed as well. I have a 40gallon with 1.4, then a 20 long with 1.3, and a 10 gallon maternity tub that I keep very pregnant mothers in until the babies are a little sturdier and wont just get trampled in the mothers original tank. I then move them back with the others until they hit the right size for feeding off. For a trio, I personally dont see anything wrong with using a 10 gallon, though if you want very controlled litters, I would recommend getting one more 10 gallon tank, and one more male. Keep the two males together and the two females together, and when you want litters, just swap rats, they'll mate, and a week later swap back. The two females will then mother the litters together and you can decide when you next want babies.

Its been a few months since I did all my reading, but Dumbo, Russian and American Blue(Your grey rat), and hooded, as well as Hairless, Albino, Black, and the Red Eyed Dilutes, are all simple recessive. The only one I can think of off the top of my head that is dominant is Rex, but im sure there are more.

You should keep in mind however, that fancy rats are like genetic grab bags, and its pretty hopeless to try and predict what will come out When I first got started, I spent days learning rat genetics trying to predict my odds, but found the majority of my rats had recessive traits I didnt see coming at all. Thats part of the fun for me. You never know what youre gonna get next litter. Good luck!