The cardinals are on their own in a separate tank from all of the others - I had neons once before but they started to drop with Neon Tetra Disease and I had to euthanaze the last couple when they started showing signs.
One LFS had two tanks of cardinals at the weekend which they weren't selling as 'they were not up to our usual size'. A different LFS had some slightly larger ones which they gave me a discount on because they were smaller than normal. He also told me to acclimatise very slowly as they were fresh wild caught from Columbia. I think he was willing to sell as he had too many in the tank.....
They're still getting used to their new home - got a few plants for them to shelter in and the lighting is not too bright. They look good when they move around as a group with the lights glinting off them.
Cheers, Eddie