I just picked up 7 black platys to throw in with some juvie beani and cyannogutattus. Surprisingly aggressive little fish, they killed off 2 of the smaller ones while they were still in the bag! I've also had luck with 6 line barbs. Figured I'd try the platy's since they were so cheap. Doing great so far.
I'd be careful with the polleni with rainbows. They will eat other fish if they can fit it in there mouth. I had a horrid experience with that with my Psittacus eating and choking to death on rainbows I was sure they would not eat. Came home to 3 dead parrots!
