Add cucumbers, salt, onions, 5 cups white sugar, celery seed, mustard seed, vinegar and pickling spice to a large heavy bottom pot.
Bring to a boil and let boil for 15 minutes.
Meanwhile, in a medium sized bowl, mix flour, 1 cup of white sugar and dry mustard.
After pickles have boiled for 15 minutes, remove from heat and stir in flour mixture.
Then add turmeric powder.
Ladle into clean sterilized mason jars. Add lids and seal using boiling method for canning.
Store jars in cool dry place. Once opened, store in refrigerator.