Mix flour, baking powder, paprika, seasoning salt and water. Stir until smooth.
Slice onions 1/8-1/4" inch thick and seperate into rings.
Drop onions into batter in bowl and stir gently with a spoon. This saves time, over dipping each ring separately into batter. Make sure all onion rings are coated with batter.
Using a fork, drop one onion ring into fat to test temperature. Your onion ring should not cook too quickly or turn dark. If necessary, reduce temperature. You want your fried onion rings to puff up and turn golden brown, not overcook. If they over cook they will taste bitter.
When fat is ready, gently drop onion rings into pot or place in fryer basket and lower into fryer.
When onions rings are golden, using a slotted spoon lift into a metal strainer to drain. If using a fryer, simply lift the basket and allow your onion rings to drain.