
good question Jazz. i am wondering the same thing. just added a male beta today to my thirty gallon which also contains a pair of platys, a cory catfish, and a minature pleco of some sort.
i was going to wait a few more weeks and see how this new addition fits in before i added anything else. i was going to purchase some gouramis as well.
also, i was wondering how you guys have done with a beta in a regular tank set up situation. the guy at my lfs told me that my last one died because it was not happy with a tank full of danios, although i saw no problems.
i think it died of some rot of some sort due to my stupidity. i am learning and improving for the better though.
for jazz: i find that gouramis may fair better in larger tanks, especially in my experience i have found the dwarf ones a bit more aggressive in a crowded tank. crowded, as in someone who does not take in account the fishes adult size to their tank space. a long time ago, before i knew anything .... i had six three spot gouramis in a ten gallon tank. to my surprise of what i know now, they did live over five years. i did not take care of them very well at all, you know all the newbie mistakes. but they adapted. maybe they were bred better back then, lol

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my sister had a handful of dwarf gouramis in a ten gallon tank and they just chewed eachother apart. the more room the better in my opinion.
that is just one opinion out of many people with more experience than i have thats for sure.
good luck to you. B)