I have two males and five females in a 40 gallon glass tank, no problems at all. The lady I got them from put them all together from different tubs too. Although I have one male female pair in there that's much older than the rest and just had their first litter, not sure if the age difference helps. I can pet my ASFs and they are not mean at all, just put a couple wheels in their cage and they will be so obsessed to run on the wheel that they ignore pretty much everything else LOL. Although I did have problems with them killing a lot of the first babies so just moved out the female today with the last of her young. Probably best to move out the females and isolate as they have young. I'm using 10 gallon tanks for that.