Season the salmon fillets with lemon pepper, garlic powder, and salt.
In a small bowl, stir together the soy sauce, brown sugar, water, and vegetable oil until the sugar is dissolved. Place the seasoned salmon fillets in a large resealable plastic bag. Pour the soy sauce mixture into the bag, seal it, and turn to coat the salmon evenly. Refrigerate for at least 2 hours to marinate.
Preheat an outdoor grill to medium heat and lightly oil the grate.
Remove the salmon from the marinade and discard the marinade. Place the salmon on the preheated grill. Cook the salmon for about 6 to 8 minutes per side, or until the fish flakes easily with a fork.
Serve immediately and enjoy your delicious grilled salmon!
