Agree, I count these among the most mean nippers out there.. sometimes even more so than the bleeding hearts. Like all these type fish, a lot of it is about needing to be in minimum shoal numbers but there is also a personality thing and the bleedings and the blacks are definately in the most fierce nipper category potentially.
They also get some size, so the combination of their size and the fact that you want more of them, to get them distracted and calmed would make it very difficult for a 15G, especially when you've used up pretty many of your 15 inches with the dwarves and corys.
~~waterdrop~~
