Mixing Rainbowfish Species in a School

I had 3 males and 3 females of both Turquoise and Boesemani rainbows and they all kinda hung out together. The males would only display to males of the same species though. I liked having both species in my tank vs more of just one. :)
 
I have praecox and threadfin rainbows, but they do not school together. I'd be hesitant to get just one of a particular type of rainbowfish, I think they'd do better with more of their own kind to school with.
 
I have 4 Boesemani, 5 Turquoise, 1 Lake Tebera, and 3 Banded Rainbowfish all together in a 90g tank. They all get along great, and school together somewhat, though I really need to get a longer tank to give them enough swimming room to really form up into a school. Once I have a tank large enough, I plan to keep 5-7 of each species.
 
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