yah know, i'm kind of hating divided tanks these days. i have 5 divided tanks right now and it seems my bettas don't do as well in them as opposed to bettas i keep seperate. you are pretty much guaranteed that if one gets sick, the rest of them in that tank will as well. i have found that seperated bettas are much healthier and happier for some reason. my crowntail "mongkut" used to live in a divided tank and at one point his rays started thinning and he was becoming lethargic, not a good thing. we ended up putting him in a thai style square vase and almost right away he was more energetic and his rays came back to life and got thicker again. even though he has less space now than before he is healthy and vibrant. just my opinion though. like i said, i still have 5 divided tanks but i don't think i will be getting more.