TheCrazyFishLady
Aquarium Advice Addict
ive read about alot of people doing betta soretys(spellcheck) just gotta be careful and watch them
*Sororities. I had one and it went very bad. It's honestly a lot of stress for you and the fish. It requires a good deal of research and pre-planning. It's a much bigger deal than what people let on to. I would say to try out some other fish than female bettas. I would not trust this set-up with a mix of the sexes. You would need lots more plants and hiding places. So, the cave decor you can pick up at a pet shop, terra cotta pots, slate caves, or anything else. You could do more of that pipe, if you like that look.
I would guess 30g isn't large enough either, but this is just my idea. The only time I have ever heard of males getting along long term in one tank was three in a 125g, well planted with a complex cave system. I'm sure males and females would be a similar issue. Some people have had no issue, of course, but bettas are very unique from one another.