First off, what a great fish. Please, if you are thinking of buying them, do it! If you haven;t thought about buying them, but are looking to get some mroe fish, give them some thought.
I recently bought 3 new BCTs. They are really small (less than 1") and one in particular is very tiny, and is so young that he even still has eyes!
The thing that is currently concerning me is that 2 of the new ones, and my existing one are powering about the tank very actively occupying top and middle areas of the tank 90% of the time.
One of the new ones, coincidentally the smallest, is also powering about the tank, and being quite active, but staying almost exclusively to the bottom level and picking about the gravel.
All 4 tetras eat like I've never seen fish eat before so he still has his appetite, and like I said he is active. I'm just slightly concerned that his behaviour is so different from the others.
He is visably the picture of health, so I don't suspect disease.