Turn your broiler’s oven to high. Line a rimmed baking sheet with aluminum foil. Place the salmon skin side down on the lined baking sheet.
In a small bowl, combine salt, pepper, chili powder, paprika and garlic powder. Stir to combine. Sprinkle the spice mixture over the top of the salmon, pressing it in an even layer on the top. Place the salmon under the broiler and cook until done, approximately 10 to 12 minutes.
In a medium bowl, combine the ingredients for the grapefruit avocado salsa. Stir to combine and set aside until ready to serve.
When the salmon is done, separate the flesh from the skin. Use a fork to break the fish up into small pieces.
Place corn tortillas in the microwave and heat from approximately 20 to 30 seconds until soft and flexible. Divide the fish evenly among the corn tortillas. Top each with grapefruit avocado salsa. Serve immediately with a little quest fresco if desired.