A beautiful little Tetra, when kept in schools the red on their fins is an impressive sight.
I have seen people use a good food like NLS Community formula and get a deep red color.
This is one of the Tetras I would take care in introducing into your aquarium, do it slowly to acclimatise to your water conditions. they don't like change too much.
Males can be identified by the white tips they have on their fins.
pH - 6 - 7
GH - 50 - 100ppm
Temp - 24 - 26c