Bring a large pot of water to a rolling boil and salt it generously. Add the elbow macaroni and cook until al dente, usually a minute or two short of the package maximum. Drain and spread the pasta on a sheet pan to cool, or rinse briefly under cold water to stop the cooking.

In a large bowl, whisk together the Miracle Whip or mayonnaise, sugar, celery seed, garlic salt, apple cider vinegar, yellow mustard, salt, and black pepper. Stir in the sweet pickle relish if you are using it. Taste the dressing and adjust for tang or sweetness.

Fold in the chopped hard boiled eggs, diced red onion, celery, and bell peppers into the dressing until everything is evenly coated.

Add the cooled pasta to the bowl and toss gently until well combined. Cover and refrigerate for at least one hour to let the flavors meld.