Is What Said On This Page True

[Fizban]

http/animal-world.com/encyclo/fresh/anab...TailGourami.php

 

[The-Wolf]

IMHO
a 20" fish is going to need a tank at least 3x its length for tank length and at least 1.5x its length for the width.
so that makes a tank with a foot print of 60"(5ft) x 30" (2.5ft). if the height of the tank is an industry std 18" (1.5ft) that would make the volume
531 ltr or 140USG.
of course this dosn't take into account any territory issues the gourami has so you may need a larger tank.

 

[nmonks]

I wouldn't recommend keeping any of the giant gouramis in anything less that about 200 gallons. They are territorial, as The-Wolf said, but my issue is that they are also extremely messy animals. They are primarily herbivores, and for the best colours you need to be giving them a lot of different sorts of plant materials. Cooked rice, sushi nori, blanched lettuce, pondweed, peas, bits of soft fruit, and so on. Feeding them live fish -- as the article suggests -- is not a good idea. Almost without exception, feeding herbivorous fish meat results in long term problems, because fat accumulates around the internal organs. (Just like in humans, really, who eat much more meat than they evolved to!) Anyway, when you dump plant material in small aquarium it tends to make the water cloudy. Doesn't harm water quality (little protein -> minimal ammonia) but the tank looks messy. So you need partly a dilution factor to make it look less messy and also lots of mechanical filtration to strain out the plant fibres and fish faeces.

Furthermore, when keeping a big showcase fish, there's always the tempation to add a couple of catfish and a few large characins or barbs, so you may as well plan for that and provide the extra space from the beginning.

Cheers, Neale