Yes, interesting about the "secretive" threads. But to the issue at hand...
just adding to what Colin posted, on the tank size, you will need at minimum a tank with a length of 4 feet (120 cm) and preferably a width of 18 inches (45 cm) so something like a 70 gallon or larger depending upon other fish species/numbers.
Their nocturnal habit means they should never be combined with quiet or sedate fish (angelfish, gourami, etc) as these fish will be stressed out by the nocturnal disturbances of such largish fish. Pictus cats also go into a feeding frenzy when food is placed in the tank, and this easily frightens many other fish.