adding more female might be good,, i have two girl tanks both 10 gal, the top has all my small or very gental fish, 10 at the most but one is out for breeding,, hope to have fry soon, and they all seem to get along great,, its is strange though, one of the smallest females was sickly when i got her and my big fat vt female would actually help her to the surface when she was very tired, and no she is not a male trying to breed her its a girl she is just a big fat hog,, she is 4 times bigger than the small one, and they never seem to fight for food,, my bottom tank though,,they only tolerate each other any way i need to get ride of some fish,, i want to breed ct and mts i need to get ride of some vts mostly reds and blues i think 3 red and 3 blue.... anyway its like everythinh else, personality,, some are nice and some are not