Originally Posted by Alimiss27
Sorry if I have offended you. To me ,thrive means to be happy or flourish, as in be the best possible form. But it is recommended that a betta be in at least a 2.5 gallon. If you would like I could tweak the article. Once again I am sorry if I offended you.
Oh, no, don't worry about offending me! You're fine
From what I can tell all my bettas are very happy and healthy. They're bright and colourful (many were pale/dull when I bought them, have since flourished), have a good appetite, are free of illness, no stress stripes, and are active.
I pretty much base the tank size I choose for each of my bettas on the individual fish's needs. The more active ones get larger tanks while the less active ones (the males with long heavy fins) get smaller. I've found that big heavy fins don't always mix well with a big tank, because the betta can become stressed if he can't patrol his entire territory to his liking.