NO! Noononono. Those pots are insanely miniscule. The fish would have a miserable existance. Those sort of "tanks" are just a moneymaking gimmick and are utterly unsuitable for bettas.
If it's the hex design you like, look around for a second hand 5 gallon hex tank. That will fit in god knows how many places in a home, so space should not be an issue.
Just a 5 gallon tank in general is best for a minimum. Ten gallons is much better. Look around at car boot sales as well as ebay. I've seen LOADS of tanks at the ones here. You can invariably pick one up for well under £10, and many often come with some equipment like filters, heaters and ornaments ect . The hex tank in my signature was £5 from a car boot sale. Classified sections in newspaper and bargain pages are also good to try.
A sponge filter or small internal cannister filter, a 25-50 watt heater, and a load of plants plus some gravel is all you need after the tank.
Wilkinsons sell bags of plain fish tank gravel for a couple of quid, and a bunch of silk or live plants ( NOT plastic! ) from ebay of your LFS shouldn't cost you the earth. Elodia, Cabomba, amazon swords and Java moss are all good live plants to start with.
Seriously you can get a great 5 gallon set up for under £20-30 if you go to the right sources.
/cgi.ebay.co.uk/Boxed-Betta-Bowl-4-s...p3286.m63.l1177
