In that case, you should give the pair a tank of their own. They don't seem to do very well in a community setting unless there is a lot of plant cover and wood or rockwork protecting their secret hideaways. As small as they are, female Apistos when in guarding mode, can defend their territory and fry valiantly against fishes much bigger than they are, including Angels. Sometimes the males help out in defense, since during brooding, the male's territory is just outside that of the female.