I am going to play the devil's advocate here. This has been bothering me lately and it's not just you, tropical, but other people too. Maybe since you are not allowed to get any more tanks, you should abstain from buying more bettas? I just think that impulsive/compulsive betta buying is rather frightening is all. I mean you do have two lovely bettas already, why not just take care of them and all your other fish?
I am really only asking why get more. And I think I mean to ask this quesiton to everyone. Why get more and more and more?
I don't mean to offend you or anyone or make this a personal grievance, tropical. I am merely curious and unable to understand the reasoning behind something that I, personally, view as superfluous.
I actually agree with this to some extent. This is a good point and it is difficult sometimes to play Devil's advocate. You handled it very well, Kyrielle. I understand people love bettas, I love them too, but try out two for a while. Maybe 4-5 months down the road, you might not like changing water 3x a week. I have had as many as 10 bettas, and let me tell you, changing 10 tanks, 3x a week, dealing with two hightechquariums, taking care of my other pets, and dealing with a full-time job or school can become a hassle. I never compromised the health of my fish, but I didn't have much of a social life!
I'm not replacing them as they die, and let me tell you, my back is thanking me.
But, if keeping multiple fish is what you want to do, then...
I also agree with many of the options listed for betta containers. I have also seen people here make very nice betta homes out of large, plastic tupperware bins that are stackable, which helps if you plan to keep multiple fish. They often would cut little holes in the top, really quite ingenious. I've also seen large vases, cheese ball containers. If I knew whether or not silicon crystals were inert, which I think they are, another option would be to trim a kitty litter jug. I know Esquisicat brand sells their silicon litter crystals in a large, very clear, plastic jug, that can easily be trimmed to make a nice 1g+ betta container. That being said, I have seen a 2.5g, all glass aquarium with a glass cover for only $9.99 at Petsmart, and that is by far, one of the best options. So if a container of cheesy balls or nuts at Costco is about $8-10, why not spend the same amount and get a real tank. IMO, it also looks much prettier, and the shape is fantastic for keeping bettas.
Warmest,
llj
. at the moment, neither of my betta bowls have heaters and both are quite active. my room's at least a steady 75F so they're good 
. thats where all my fishies are 
. minus the goldies. those are my mom's office fish. everyone there loves them.
