In a large bowl make the marinade by mixing together everything, except the tilapia.
Place tilapia filets in a dish with high sides. Pour the marinade over the fish and gently flip the tilapia so they are fully coated. Cover with plastic wrap and place in the fridge for 1-2 hours.
Heat grill to high heat. Place the tilapia filets on the grill and cook for about 3-4 minutes. Very carefully, flip the fish and grill for another 3-4 minutes.
Remove from the grill and let rest for a couple minutes.
Crumble the fish and place some on a soft floured tortilla shell. Top with guacamole, grated cheese, tomatoes or other taco toppings.