All of those tanks have WAY TOO MUCH water in them, you need to remove a few inches. It looks like your fish might be able to easily jump out of the fluval since it's not covered. Plus bettas need surface air to breathe, in those tanks they don't have any.
There IS surface space in all the tanks o.O Most people fill their tanks to the rim, and theres still room at the surface between the light and the water in the third tank. But in the lidless ones, I see your point.
WARNING: Don't get a betta if you mind being addicted to them! They are horribly addicting.
Yeah, I wish someone had told me that before I brought the first one home from my animal behaviour class. My room-mate has become a total Betta junkie and it has become massively contagious. I would have been perfectly fine with just Hamlet, but then we started talking about breeding him, which led to us buying a 10 gal tank on-line, which led to Ophelia, which led to the other 5 at various stages, which led to Ariel, etc & so forth.
Addictive is right, but I don't regret getting hooked.
Thanks for the advice on the Fluval chi. I didn't realize the water was so high in the picture. I will make sure the water is lower in the future. This is what it usually looks like....the picture is kinda blurry, but you can see the lower level..
I've only had my Jimmy a week or so, and I'll be making several changes to the tank to make it more Betta-friendly, but here's his current set-up. This is a 6-gallon Eclipse tank and he's the only occupant. (Also, although he looks blue and red in this light, he's actually green and red; like in my avatar. Weird that he looks so different under various lighting.)