A three spot (blue gourmai) will claim about 3 linear feet of tank space as its territory (this from experience). They are the most aggressive commonly available gourami. They get nearly 6" long fully grown, though none of mine have ever gotten longer than 4". In a tank 3' long or less, you should really only keep one. If you have a 4' tank, you could keep one male and up to 3 females. In a 5' tank, you could probably keep 2 males and 3 or 4 females (but be ready to have a bailout solution if the males get too nippy). To really keep a good school pretty much requires a 6' tank, and even then, no more than 3 males, and at least 2 females per male (so max at 9 or 10). That formula works for any of the larger (yet not giant) gouramis - Blue (Threespot, Gold, Lavendar, Platinum, and Opaline), Pearl (territories are a little smaller), Giant/Thick lipped (Colisa sp., not the true Gourami - Osphronemus goramy, also called Giant.), and Moonlight. Snakeskin gouramis and Kissing Gouramis get up to 11" long, and you can count on 7 or 8", so fewer. You can shrink the territories a bit with judicious aquascapint to break up sightlines. planting the middle of a 4' tank with tall stems nearly to the front might allow you to set up a male with territory to either side of the grove. It might not, too. It'll depend on the fish. It might work better if you divide the tank on the phi spot (a bit more than a third of the way in from one end) with stems and tall driftwood. That way, whichever male is dominant will get a larger terrritory. This would be the way to go with mixing medium sized and dwarf gouramis too.
You can keep dwarf gourmais with middle size gouramis in a 3 or 4' tank if you give them plenty of plant cover to duck into. I wouldn't mix Dwarves and Blues in a 3' tank, but maybe in a 4'. I might put a dwarf and a pearl in a 3' tank, particularly if it had a 36x18 footprint and plenty of plants.
Now, I have not kept Dwarf gouramis, so I can only guess at territory size. I wouldn't keep more than 2 males in a 3' tank or more than 1 in a 30" tank (Maybe 2 dwarf honey gourami males, Colisa chuna). 2 or 3 females per male if you want more fish. A 20 long with a male and 3 female dwarf or honey gouramis would be really pretty. |