i think it would probably be better for you to take one of the males out and then add the female, just watch for 2 much aggresion, i say 2 much because when i did this in my tank (exactly the same except i introduced a 2 inch male to a 1 1/2 inch female, and moved my other con to another tank) there was alot of chasing around for a couple days nothing to bad in the way of biting or fin niping and now i have a nice batch of about 100 fry