I have 3 bala sharks, did have 4 but one unexpectedly died?!?!
The comet barbs you are refering to I know as Denisoni barbs. I only have 3.
Dunno why they havnt eaten the carinals, I also have a load of black neons in there and a couple of cherry barbs left. They havnt eaten any of them, but they do tend to stay out of there way.
The tinfoil barbs are 10-15 years old, im fish sitting them for a friend who has moved house and hasnt had a chance to set his tank up, looks like I will have them for a while. I was scared they would gulp up all my fish, but I havnt lost one yet!!! They dont really seem to chase them either, I just make sure I feed them up well! lol.
Think the tinfoils barbs can grow to about 14 inches or something