I didn't vote because my bettas only flair when they're in veiw of another betta.
And since their tanks are devided by shelves, they can't see eachothers....
The only one who ever flares is George and that's at me whenever he's in the mood. They are all within sight of each other, but seem to just ignore each other.
Mine really just flare whenever they want, none of them are too close, except the ones in the divided 10. But my Berlioz flares at everything! Me, his tank ornaments, his filter. Food! Everything!
I don't flare mine daily anymore, although I used to. I know, I ought to. Generally, when I do flare them, it's around 15-20 minutes long. Any longer than that, and I start to see fin damage. I once fell asleep while they were flaring, woke up, and Furin's tail was in tatters. He's since completely healed over, but the damage was pretty significant.
I don't flare mine. Most of them are in tanks close enough to one-another that they can occasionally catch a glimpse of a neighbor and have a little flare, but I'd estimate that this only happens about 5 times a day and lasts less than a minute each time. The split 10 gallon has mesh that the bettas can barely see through, so the same applies to it. Its residents only occasionally see the outline of another betta float by
Well this was hard because I didnt know whether to put less then 10 or all day long...since I dont purposely 'flare' mine. I have a situation like synirr where they are somewhat close enough to catch a glimpse...but normally dont pay to much attention otherwise....
I don't really see the sense of intentionally flaring them. If they have plenty of space, plants and caves to explore, and good food, I don't see the need to "entertain" them in this fashion. They'll occasionally flare at me if they are feeling ornery, but it seems to me that intentionally aggrivating them would be stressful; I wouldn't intentionally do it unless I planned on fighting them (which I never will).
I am actually finding that I need to put up a thicker dividers between the tanks of two of mine, because my self mutilating beta can occasionally glimpse his next door neighbor, and he has very literally been eating himself alive from the stress. I also see an increase in fin shredding/rot when my bettas are in plain view of one another.