Depends on the bettas personality. Some like the space, and some prefer smaller spaces. I had a male VT in a 6 gallon, but then moved him into a 2.5. The next morning I woke up and half the surface was covered with a bubble nest so I think he is one of those who fall into those who like smaller spaces.
Hmmm, so that means dividing a 5 gallon would be too cramped as well. Not seriously thinking of it anyways but I imagine if I did divide it then Jack would blow bubble nests. Right now he doesn't bother, just cruises his domain. Does anybody else's Betta sleep by wedging himself in among the plant fronds and just sitting there?
To answer the question, I admit I'd divide a 10 into two 5's. Let us know what you do and what type you buy ok?
I have a 2.5gallon divided tank for bettas. I know a lot of people would think that's small, but it's actually relatively roomy and they've both seemed happier since I divided the tank. I'd love to give each one their own 2.5g, but due to lack of space and money [It's all going to my 15g community tank] it just wasn't feasible.
I see very little wrong with dividing a 10 gallon into 3 compartments. You wouldn't get a lot of viewing space from the front I think, as the sections would be deeper than they would be wide, but it would be a nice setup.
my betta was in a 5gallon and he had a hard time finding food and i would always overfeed bcuz he wasnt gettin enough until one day there were a lot of little white worms crawling on the side of the tank walls!. i think they are called ..... i dunno if forgot...