I setup a 20 gallon tall for 0.2 phants. Plenty of hides, branches,etc. One is like 2 months older but roughly the same size. However I think the older one maybe stressing out the smaller one. They were raised apart but have the same parents. The older one has not left her alone and although I have not seen any aggression the older one stares at the other one and seems to follow her around the tank. The older one is a year and 3 months and the other one is a year. I pulled the smaller one tonight and put her back in her old enclosure which she cant stay long cause its just a large kritter keeper which was her grow up cage. I pulled her cause she was laying on the bottom of the tank and although she wasnt lethargic (she would still climb, jump,etc) I'm not willing to risk it. I know females can be little turds sometimes but I have never had issues with phant females being aggressive to one another just males. I am sure these guys are both ladies cause they have been laying slugs for a while. I would like them to stay together cause I plan(ned) on putting a male with them. However, if she is not gonna be nice I wont do it. Any thoughts? thanks.