I've got the 5 gallon Fluval Chi with a single Betta and I did a fair amount of research on the jumping aspect myself before the purchase. Now granted I've only read about and never researched it personally...but my understanding is that Bettas most commonly jump when they simply don't want to be where they are anymore.
From what I've discovered, the jumping trait is an instinct they have due to the fact that the puddles they are in at certain points in the wild will begin to dry out or become overly dirty / polluted, and it is their intention to basically hop over to a new, more suitable location.
The approach I'm taking with my Chi is to provide as happy and suitable location for him as possible where the instinct to change locations would never cross his mind, and he'll be more than happy to stay put. The guy has been building bubble nests repeatedly, so I guess he must think it's a place he's willing to stay for a bit.
I know there are plenty of fish that jump do to being skittish or overly active...but from what I'm seeing so far I'm not overly concerned at this point. Hopefully I won't learn the hard way that my research is wrong.
The Chi's are a bit of a scary design because in order to maintain the aesthetic look it basically has to be filled to the rim. I have floating Water Sprite which he will use as a hammock occasionally and can probably see over the edge of the aquarium, lol.
I'm keeping it hoodless, but I'll definitely update the site if he jumps out of his home for whatever reason.
. Good thing it's moss, that's the only thing you can grow in there, lol. I'm killing Water Sprite left and right. I'm pulling some of my floating plants out of my DT and putting it in the Chi every week just so the little guy has something to lounge on. That LED light is borderline useless.
