The tank and betta aggression

[cnbufford]

Is it possible for a betta to flare up his gills so much that they stay that way?
The aquarium my betta's in apparently reflects his image a little too well. He's provoked by it frequently, if not constantly, patrolling his turf and flaring up much of the time. Is there such a thing as choosing the wrong tank (this one's a basic 2.5 gallon plexiglass with filter and light)? Is adding backing the best solution and which is best to prevent him from becoming too stressed out? Or does he simply need more estrogen in his life?

[sainthogan]

Do you keep the room lights off while his tank light is on? If so, this is what is causing the extreme flaring. I don't know that they will get stuck that way though, unless he gets some sort of infection that isn't related to flaring.

[cnbufford]

More light in the room could work, too. Thanks!