For my betta I have a one gallon bowl and some rocks at the bottom. i use store bought fresh water and once a week take the betta out and put him in a cup with some of his water. I dump and rise all the rocks off and wipe the sides, make sure you don't use soap or any chemicals when cleaning. I fill the bowl with room temperature spring water and put in 1/2 tsp water conditionar for good measure. I feed my betta flakes but there is also the pellets. My betta is extremely happy and lively and i don't have any filters or light, pumps, or heaters. I actually lucked out and at a yard sale they had three betta bowls, rocks and plants, and a net for $0.75.

The one thing I would reconmend is using spring water because we have well water and it isn't entirely clean, so the water killed several of my bettas and my brothers.