What other fish? Just balloons? Mixed sex, or all male, or all female, or what?
More info would be good. And also, I'm assuming the tank is already cycled?
Also, consider, that if you do mixed sex, you'll have fry. I can pretty much gurantee you that. And figure each female has 10 fry per month...and you need 2-3 females per male. So that's probably at least 20 fry per month. There are other stocking options, and also some more info about fry in a topic I wrote Here.