Oh I see. Well, I've come down to a final 5;
Black Neon Tetra
Black Phantom Tetra
Ember Tetra
Glowlight Tetra
Neon Tetra
Head and Tail Light Tetra
I did quite a bit of research, and averaged everything out, so I came to this:
Black Neon:
Possible adult size: 4cm
Number in shoal: at least 4
Black Phantom:
4.5cm
4 or 5
Ember:
2cm
at least 4
Glowlight:
4-5 cm
at least 4-5 (lots of mixed opinions on that one)
Neon:
3 cm
at least 5
Head and Tail Light Tetra:
5cm
at least 4
In terms of looks, my preference would have to be either Black Neon or Head and Tail Light.
I don't want to go for a really small Tetra, like Ember, in case my Betta eats them. On the other hand, I don't want to go for a relatively large Tetra, like Head and Tail Light, if there's not going to be enough room. : s
What do you think?