First build a medium size land exhibit, put down dirt, gray stone, I can't exactly remember what terrain, Put what zookepper reccomends, Place saltwater throught the exhibit untill they get mad. Place beach grass along the shore, put in a tank, make it level with the other exhibit, put in sea plants from the otter's region, put in the marine rocks(not real name, rocks that go in the tanks) in the tank. Place a tank filter. Hire a zookepper and maintence worker for maintence.