I have in my tank 5 white skirt tetra full grown and 4 serpea tetras around 4 cm each.
I am thinking of getting 5 cardinal tetras and 5 neon tetras? Will they be fine in my tank.
Well tetras can be on the nippy side sometimes, but if they skirts and serpaes you already have arent nipping each other, I doubt they would bother with the cardinals and neons and neither cardinals or neons are nippy IME.