BronzeWolf
Fish Crazy
Well it could be that since he is new he is adapting to his new surroundings. If he is a timid chap then if you have transparent dividers he could be a frightened by the betta next to him, try inserting a opaque divider, if you cannot do this give him some floating plants to hide in. Perhaps the amount of space although plenty to swim around in is too big for him and he would feel cosier and more comfortable in a one gallon on his own, that is what i thought about doing to my poor chap when he was just floating still in his 2.5 gallon.