I float him in his cup for 20 mins and add a little new tank water to his cup, float him for another 10 mins. His new tank water has been aged before I add more Prime to it and temperature is the same at 76. Mini-bow did come with a filter which I have turned off after a day because he was freaking out. Did a partial water change. Lights are different, I didn't use the tank light but his current spot is nearer to the window, not near near but nearer than before and I think it may have affected him. I have posted a video on youtube how he is swimming. Please take a look and let me know if he will be okay. I know some bettas swim like that when they are sick but since I just changed his tank, I am not sure which is which. I honestly think he doesn't like the bigger space and prefers his 2 gallon.
http://youtu.be/9wLt6Q6WzTI