I just got a pair of Bangaii Cardinals and was wondering what kind of setup i'd need to try to breed them.

I have two pairs producing right now. One pair is in a 25G breeder tank with my pair of Orchid Dottybacks and the other is in my 70G with a few pairs of blennies and gobies. Both have been spawning, but the pair in the 70G seem to be doing better. It's a challenge to catch the male to get him to release the babies in the 70G sometimes, but they seem more at ease in the 70G with other fish. The pair in the 25G spawn less frequently, but not sure if it is due to the age/size of the tank/environment or not. I can provide more info if you need, lmk.
bob

i have a 12gallon nano i was wantig to set up just for them whould that be ok or should i invest in bigger a tank. they are in my 210 now but i think they'ed do better in a tank by themselves

I am actually thinking of moving my adult pair to my 210G in a group setting. The pair in my 70G seem to do much better than the ones I have by themselves. But I think you can go with the smaller tank successfully.

Bob