Spicey Crock Pot Sauerbraten  Roast

3-1/2 to 4-1/2 lb. beef roast
3 cups water
1 cup cider vinegar
4 heaping tsp. brown sugar
1 (14 oz.) bottle ketchup
2 large onions, leave whole
Salt and pepper to taste
3 whole cloves
4 bay leaves
1 heaping tsp. mixed pickling spices

Combine all ingredients except meat in slow cooker/Crock Pot. Stir well. Place roast in mixture. Cook on low heat for 10 to 12 hours.