Originally Posted by Neil D
Theres a difference between holding his fins out and flaring, that difference being one stresses him out and the other doesn't.
Like a person with his head held high, chest out in confidence, versus one with his head held high and chest out with an intention to cause fear.
Flaring doesn't really cause stress. IF done too often(24/7 often) then it could cause stress.
Flaring is a very healthy exercise. Much like it is very health for us to run. But like wise if you run too much you can do more harm than good to yourself.
The difference between holding their fins out and flaring isn't always stress. 99.9% of the time I see a betta holing his fins open is when he is stopped/just "floating" there.
On a side note, I HAVE seen some bettas swim with their fins open and obviously not flaring. but they often don't do that because it is harder for them to swim with their fins fully open.