Prepare two jars by sterilizing or running through the dishwasher on a high heat setting. This should be done so that they are ready just prior to the layering of the cucumbers and onions.
Combine cucumbers and salt in a strainer, mixing with hands to cover all the cucumber slices. Place over another container to catch any liquid, cover and chill 1½ hours. Rinse thoroughly under cold water. Drain well.
In 2 prepared jars layer a little onion, then a layer of cucumber. Continue layering until jars are full, ending with cucumbers on top. Add 1/4 teaspoon pickling spices on top of the cucumber.
Combine the vinegar, sugar, and turmeric in a small saucepan. Bring to a simmer over medium heat, stirring until the sugar dissolves.
Pour the hot vinegar mixture over cucumber mixture; gently nudge with a clean knife or another utensil to remove any air bubbles. Top off with more of the vinegar mixture. Let stand at room temperature for 1 hour. Cover and refrigerate 2- 24 hours.
Store in an airtight container in the refrigerator – will keep for weeks.