My tank is the same length as yours only taller. My rainbows are a tight group. They all swim from one side of the tank to the other side together. So, having all 6 on one side, makes the tank look crowded.
Maybe just go with 6 of them. All of the other fish in tank swim at a different level. That leaves more room for the rainbows. I have my cories, rams, and eels at the bottom. Then I have my bettas, that don't really take any room away from the rainbows.
Be careful about adding any very small fish. The rainbows are not really aggressive, but they will mistake a small fish as food. One of my female bettas is red. When she was first introduced to the tank, I think they though she was a bloodworm.
I had to take her out, let her grow a little more, then she was fine with them.
Last edited by Twistersmom; 09-08-2009 at 02:06 PM..