Sometime ago, some colleagues showed pics of their stone fish and I really wanted to keep this fish, but one by one, they died, and without reason. The conclusion was that they can't be kept in FW. But if your colleagues have kept them, perhaps find out how they do it. I remember vaguely there could be a feeding problem as they don't move a lot, but to get around this, those small catfish feeders can be deployed as they swim right into the fish's mouth. I really wanted to keep one of these coz they look like the Sesame Street Oscar, really comical looking.