I personally think they are too small. A friend of mine has hers in them, and they bubblenest away every day. They swim to one end, investigate and then swim back to the other side and investigate. They are happy, healthy and really enjoying their home. You can get them in bigger sizes, I have one that is 2.25G. I have seen 1/2G-5G in that style. Mine however was only the tank, no gravel etc... I really think it is up to you and what you like and/or have space for. If you get one that size and the betta doesn't seem happy, you can always upgrade later.