Cover fish with cold water to freshen. Let stand in cold water 4 hours, changing water 3 to 4 times (or follow directions on package). Drain fish and remove any pieces of bone. Flake and set aside.
Wash, pare, and cut potatoes into pieces. Combine fish, potatoes, and onion in a large saucepan. Add cold water to cover. Cover saucepan and bring to boiling. Cook until potatoes are tender.
For dill sauce, combine all ingredients. Mix well. Refrigerate.
Thoroughly drain and mash potatoes, fish, and onion. Add eggs, paprika, and pepper; whip until mixture is fluffy. Using 2 tablespoons of batter for each, shape into balls.
Heat Crisco to 365ºF in a deep saucepan or deep fryer. Drop only as many fish balls at one time into hot Crisco as will float uncrowded one layer deep. Fry for 2 to 5 minutes or until golden brown, turning balls as they brown. Drain on paper towels.
Serve with Dill Sauce.