Just here to learn all I can to help my 4yr old daughter care for her betta, Fred. We currently have him in a 2.5 gal
Aqueon Mini Bow tank with the included filter, which seems to be working well. We have a Marina submersable heater as well. Fred seems to be very happy with his current setup.
My daughter LOVES fish and I do foresee us possibly upgrading to a larger aquarium at some point and more fish. but for now, everyone seems quite happy with our 2.5 gal