RE: Do not keep more than one Gourami in the same tank
You can't keep 1 male and 2 to 3 female gourami in the same tank. They are not guppies. Like I have said (and tried), the female dwarf gourami are also aggressive toward other gourami. Territorial and aggressive is not just a male thing when it comes to gourami. So in this case, not only the 1 male will be aggressive toward the females, the female will also be aggressive toward each other as well as to that male if given the chance.
To breed dwarf gourami, it is recommended that you need to let the female establish her territory first in a tank of herself. Condition her with live food. Then add a male to the tank. The male will be less aggressive since it wasn't his territory to begin with. If you have enough fine leaf plants in that tank, the male will try to build a bubble nest with those plants. Once the nest is built, the female will go to the male for spawning. You can see the link in my signature for the videos.