Originally Posted by Neil D
What if I redecorated so the decor is new to the betta, but gave the tetras time to get used to it. Would this be an added safety?
If that specific betta has already shown aggression, changing the decor won't make him less aggressive. It could for a few days while he gets his territories set up, but once he does he will have no problem nipping if he deems it necessary.
Sometimes bettas are just too aggressive to have tank mates, no matter what precautions are taken.