Answer by
DeadlyGlories (71)
I'm going to take it that by "black goldfish", you're referring to black moors, so getting other egg-shaped, slow-moving goldfish is your best bet. Fish like lionheads, bubble-eyes, and orandas look very nice with moors, and will generally be your best bet. Fast-moving goldfish and tropical fish and algae eaters should be avoided, as they may pester the slower fish.