I use tanks too but building racks soon here running outta room kinda pumped for it I'm gonna set up twelve tubs I think cuz I wanna make sure I have all room ill ever need and two 6 set racks fit perfect in the space I wanna lose. Far as females together so far I haven't had luck specially with a girl with a litter and ones that dont have them, one girl was just always in the way laying with mom and babies but never took them, the litter I just had tho she had two siblings with her I pulled them out ASAP when the one was giving birth the other girls wouldn't stay away and were messing with her she ate one and was eatting a second when I took the other girls out after they left she mellowed out it was her first litter so that probably played into eating babies