200g? About 900L because there is also Sorubim Limia... but you would have to build tankmates around them, nothing too aggressive and definately nothing small. Mine lived at various times with discus, severums, loach, a stingray, other catfish species, leaf fish and a tyre track eel.
They arent the most active, they tend to sit still facing downwards which is where they eat their food from... and dear god do they eat! a LOT of Hikari Massivore pellets, prawns, cockle, mussel and novotabs etc...
But when they do swim, they move really fast and need the space, mine hated having too much decor in the tank and generally redecorated to suit him anyway! so rock, bogwood and plastic plants lol