Depends on the individual fishes personality and what you call active. Wolf fish are ambush hunters not open water hunters like alot of the other Characins. They do spend most of their time laying in wait so how you decorate your tank is gonna be key. If you have lotsa caves and really bright light the fish may be hidden for long periods of time. If you have minimal hiding space and low wattage lighting you'll probably see them more often than not.