The rumor seems to have started because bettas live in rice paddies in their natural environment. However, while they may not be deep, they cover extended areas and give the little buys a lot of room to roam.
I've kept bettas for many years and have kept them in a variety of different tank types. Here are four that I've used, with my recommendations for my favorites. I've also shared some precautions, since bettas can be jumpers, so you risk a fishy suicide if your tank doesn't have a top.
•Hagen Marina Geo Bubbles Betta Kit Review
The Hagen Marina Geo Bubbles Betta Kit is very nice looking., since it has a decorative backdrop. This type of tank actually comes with a variety of backdrop prints.
Although it's small for a betta, this could still be a good tank if it weren't for one small danger. There's no lid, so a betta can easily jump right out. I discovered this the hard way with my betta, Spookyfish. I had no idea that he was a jumper until I came to feed him one day and found him, dead and dried out, on the floor.
Using a cover on this tank spoils the aesthetics, so I wouldn't use it for a betta at all. However, I did discover a good use for it. I got a feeder guppy by accident when I purchased some ghost shrimps to help housekeep my current betta tanks. I named the guppy Jeff, put him in the Hagen Marina Geo Bubbles Betta Kit, and he's resided there happily ever after.
With a tank like this, bear in mind that there's no filter, so you must clean it frequently.More »
•Marina Betta Pals Aquarium Kit
I really like the Marina Betta Pals Aquarium Kit, although it's still a bit small for a betta. I had a little guy named Gil who lived quite happily in this tank for many years. It comes with a little plastic plant, and that was his favorite hangout.
Happily, this betta tank comes with a fitted lid. It has some air holes, but with the way it fits, there's absolutely no chance that your betta can jump out.
This tank has no filter, so you need to clean it frequently. I generally cleaned Gil's habitat every week, and he remained healthy for his entire lifespan.More »
•Fluval Spec Nano Aquarium
My current bettas both live in nano aquariums, complete with filters. The first is the Fluval Spec, which holds just over two gallons of water and is very attractive to put front and center in your living space.
I recommend this aquarium on almost all counts except for one. Even though it has a lid, a determined betta can still jump out. I learned this the hard way, as its first resident jumped out and disappeared (sadly, I suspect he ended up as a dog treat).
Fortunately I was able to rig up a cover that keeps my current betta, Klaus, safely inside. Overall, he loves his home. I was worried that the filter was agitating the water too much, but it doesn't bother him at all. He even loves to hang out against the intake filter.More »
•Fluval Edge Nano Aquarium
The Fluval Edge Nano Aquarium is six gallons, so it's toward the larger end of what you need for a betta. My fish, Cartman, seems to enjoy all the space. I often see him exploring it before he gets tired and rests in his artificial plans.
The filter works very efficiently on this aquarium. I was worried about the water agitation, but Cartman pretty much ignores it.
The Edge is a great aquarium, except for one tiny thing. It has a very small opening at the top, which makes it a challenge to rearrange plants and other decorations. Luckily, I don't do that a lot, so I'm very pleased with this set-up. It's a toss-up between the Edge and Spec on which one I like the most.More »