Originally Posted by Laser
In my experience male gouramis just hate each other, they don't have much to say or do with another species. Pearl Gouramis are one of my favorite fish and for the most part they are peaceful... except for that one time I had a male and a female and the male became agressive to everyone in the tank. I think he died of over-exaustion. What I would do is give it a try and watch them closely and see how it works out.
There are a few tricks I have leart with Gourami's, The have a pecking order just like dogs. The alpha gourami will spend almost all his time at the top of the tank, and will only really attack the others when they attempt to get near the top of the tank. To short circuit this you need to
(A) Make sure that food submerges so that the less dominant gouramis don't go near the surface.
(B) Keep the tank well oxygenated so that the fish do not need to hang around the top of the tank and
(C) Grow some tall plants around the tank and have lots of high bushes that the smaller gouramis can hide in.
A few other things that are really important is to try to get all your gouramis at the same time, so they are pretty relative in size. Any new gourami I get spends 3 or 4 months in quarentine getting ready for the main tank (I play them the rocky montage every day too
) And make sure that the fish have at least 6 hours of really, really dark night period. All gouramis rest in the dark and it gives them all a chance for a breather.
These things will not solve or your aggresion problems, but will definately calm things down.