I was going to get some platies to put in with my betta but the petsmart lady said that because of there bright colors and realitively similar size the betta would attack them. Have you guys had this problem?
Platies are generally compatible tank mates as long as you obtain one that doesnt have long fins, or multiple bright colors. Some bettas have been known to pick on them and stress them out if you do get any brightly colored up ones. I myself placed a male betta and a platy together in a tank and they were fine, at first the male did chase him around and flare at him a bit, but after about 2 hours he stopped
I've had platys and female bettas in the same tank before.
They pretty much ignored each other.
I gave a few of the platys away to a friend, and kept two babies. They both turned out to be males, and now they try to court and mate with some of the betta girls. Silly boys.