In a large bowl mix the cucumbers and salt together, chill 2 hours.

Drain in a colander to remove the liquid, rinse the cucumbers with cold water to remove the salt.

Return to the cucumbers to the bowl. Add the sliced onions to the bowl and toss with the cucumbers.

In a medium saucepan combine the sugar, brown sugar, white vinegar, apple cider vinegar, mustard seeds, celery seeds and ground turmeric. Bring to a simmer over medium heat, until the sugars dissolve.

Pour the hot mixture over the cucumbers and onions mixture. Let stand at room temperature for 1 hour.

Cover and refrigerate for 24 hours.

Store in airtight container for up to 4 weeks.