We actually have lost few cardinal tetras after getting her, and I'm sure it was the emerald, but the cardinals are getting to old age as well, so we are already thingking of finding a new kind of shoaling fish that would be big enough to survive. Or we just might take more siamese algae eaters to get their school bigger. Don't know.
The old set of cardinal tetras came with the tank, so they are clearly old (maybe 4 years already?) and we kind of saved the emerald. She was being bullied by two male emeralds in a tank too small, and their owner was desperate to find a home big enough for her, and basically we were the only option within 70 km.
It's a shame that the cardinals are so colourful, they would have looked wonderful in a big school. Any ideas of a schooling fish that is colourful but way bigger and could do with the fish I already have?