5 1/2 cups thinly sliced pickling cucumbers (about 1 1/2 pounds)
1 1/2 Tablespoons kosher salt
1 cup thinly sliced onion
1 cup sugar
1 cup white vinegar
1/2 cup cider vinegar
1/4 cup packed brown sugar
1 1/2 teaspoons mustard seeds
1/2 teaspoon celery seeds
1/8 teaspoon turmeric
Drain; rinse cucumbers under cold water.
Drain; return cucumbers to bowl.
Add onion to bowl.
Combine sugar and remaining ingredients in a medium saucepan; bring to a simmer over medium heat, stirring until sugar dissolves.
Pour hot vinegar mixture over cucumber mixture; let stand at room temperature 1 hour.
Cover and refrigerate 24 hours.
Store in an airtight container in refrigerator. (I use canning jars for storing.)