I had a betta in a vase years ago and decide to get another one. After a few weeks of research I realised that a vase with no filtration / heating is not the best environment!!
So, spent a bit of time and $$ getting an Aqua one 3 gallon tank with a 25w Theo heater and filter. I didn't like the rocks that came with it so bought some different rocks and silk plants to keep him happy
Let me know what you think of Bo's new home. He seems pretty happy. The first few days he was quiet as but now he can't stop movin'