Ya I wish people wouldn't advertise small tanks as betta tanks. Yes, they can live in 0.25gal of water the same way you can live in a closet. Are you going to be happy? Neither is the betta.
The notion comes from bettas in the wild being found in shallow water, therefore people think well if it comes from rice paddies 4" deep, it must be able to live in a small amount of water. What they don't take into account is the fact that it may be 4" deep but it is 1000 sq miles in length and width.
20g platy, , 2 x 10g shrimp, 3 x 20g shrimp, 7.5g shrimp and 1 great dane/mastiff puppy.
Sump Pimp #2
My Tanks and my shrimps