Heat vegetable oil in a deep fryer or a large pot to 350°F.
The oil should be deep enough to submerge the fish completely.
In a bowl, combine the all-purpose flour, cornstarch, sugar, baking soda, baking powder, garlic powder, onion powder, and paprika.
Mix until evenly distributed.
Slowly add club soda to the dry mixture, whisking gently until you get a smooth batter.
Make sure there are no lumps.
Pat each fish fillet dry with paper towels.
This step ensures the batter sticks properly.
Dip each fish fillet into the batter, allowing any excess to drip off.
Fry the fish fillets in hot oil for about 3-4 minutes or until golden brown.