Do not keep more than one Gourami in the same tank

I know, I used to keep a school of 8 kissing gourami in a large garden pond with enough space for them to at least stay away from each other and keep the peace! I used to live in the tropics and the temperature and amount of light was optimal for their growth and well-being. They each grew almost a foot long!

Luckily the large pond and dense vegetation (I put in lots of water lilies) gave them enough space to avoid fighting with and killing each other.

Yes, gouramis are extremely territorial and aggressive with each other and even with other fish!