I don't think black phantoms would enjoy the higher heat requirements noto's like, they come from the Mato Grasso region, much cooler. Not sure about the congo's though.
As for difusing the aggression, I'd have to say in my tanks it didn't make a differance if they were alone or in a full tank. When kept as male/female, the male wouldn't let the female out much if at all except during feeding, and there was still much chasing. When get in 2m/2f, they didn't pay any attention to the dorsigera or tetras, just each other.
As for difusing the aggression, I'd have to say in my tanks it didn't make a differance if they were alone or in a full tank. When kept as male/female, the male wouldn't let the female out much if at all except during feeding, and there was still much chasing. When get in 2m/2f, they didn't pay any attention to the dorsigera or tetras, just each other.