One of the reviews says this
"Actually the above reviewers have INCORRECT facts. Betas come from Thailand and live in tiny little tidal pools and have also been found in tiny pools of water in rice patties. They thrive in tiny little environments as well as larger ones. Also, the only reason their water would become dirty is from OVER FEEDING. Betas are known for their cleanliness and can go without a water change for a very long time as long as they are fed sparingly."
*sigh* I like how people act like they know stuff when really they don't. This person doesn't even know fish poop.