They get to about 25cm max. And that would be a huge mouth almighty, usually 10-15cm.
They are mouthbrooders and the males put on an awesome colour during breeding time.
I’d recommend a tank that is wide and tall, as it gives them more space to hide. Chuck in floating leaves and they will love you. They hide in it and lay motionless waiting for food, like a baby barramundi. Driftwood cover is a must. They love plant cover. Lots of live foods.
As far as water, pH 4.5 - 8.1. Can tolerate temps up to 34 degrees Celsius. Mate of mine bred them in a tank 22-24 degrees and was filler with java moss.
A pair would go fine in a tank about 3ftx2ftx2ft, but I consider that the bare minimum. 4ft and upwards would be great.
other than that, great with larger fish that won’t fit in its mouth relatively peaceful fish.