Same experience here even in a 7ft tank, it was a constant power struggle. Had an old purple established and introduced a pair of helfrich and an orange. The purple was more aggressive and the helfrich pair stuck together being chased. The orange stayed in his upper corner. Then one of the helfrich gained courage and it was a back and forth fight for months with torn fins all the time. When the purple submitted and hid more, that helfrich turned on the other and eventually killed it. Orange ended up jumping through the netting, probably being chased. Now one purple and one helfrich stay on opposite ends of the tank but are very reclusive so I don't get to enjoy them
