Semi Aggressive vs Schooling

[duncanrc]

Hi
I am looking for a suggestion or two of a fish that would encourage my schooling fish to swim together. I have runny nose, amber tetra and Cardinals in 120 gallon planter tank with plenty of room to swim.

 

[SwampeastMike]

My blood red parrots are beautiful, enjoyable and coexist well with even neon tetras.

I presume you know that different species of tetras are very unlikely to school together so you need a fair number of each. How many do you have of each? In a tank that size a dozen or so is the minimum.