from Savoring Time in the Kitchen
1 cup vinegar
1 cup water
1 cup sugar
1 teaspoon celery seed
1 teaspoon salt
3 cups peeled and sliced cucumbers
1 cup peeled and thinly sliced red onion
Mix first three ingredients and stir until dissolved.
Place cucumbers and onion slices in a large enough bowl to fit them plus the liquids. Add liquid mixture, celery seed and salt and stir to combine.
Keeps in the refrigerator for 2-3 months.