This is a discussion on Betas in a community tank? within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
I have been reading and reading and now I have myself utterly confused! You can put them with tetras, but not big ones, no ...
Depends which tetras and rasboras you want to keep it with. Platies are absolutely fine. I've kept a betta in a large community tank before. There was plenty of space for him to live with my praecox rainbows, corydoras, angels, pencilfish, tetras, rams, etc.
I've never had that problem. But he confined himself to strutting in the middle and going to the front top left corner where he created his bubblenest while the rest school at the back or lower level as they were intimidated by several angels. That's as much as I can remember.
Almost a decade back, I had a compartment for four bettas. It sunk one night and all four swam together. The next morning, one was found dead with shredded fins, two extremely injured while the last one was perfectly fine. The last one simply kept to himself. They must have brawled each other to death all night while I was asleep. No other fish including the lone albino tiger barb dared to even approach them even though I theorized others were involved. The more likely theory is the bettas brawled each other to death. =3
I had a male betta in a 29g for a couple of years and no problems with the other fish (it's been a long time ago, but I remember having a red-tail shark, black shark, pleco, guppies, and corys in the tank). More recently, in spite of some written recommendations against, I had a male betta in a 55g with several male and female guppies. No problems. Once in a while he'd chase the male guppies, but the guppies literally could back away from him faster than he could swim with all the betta finnage! I think sometimes it depends on the personality of the individual fish.