Slow Cooker Barbequed Beef Ribs

1 C water
1 C ketchup
1-6 oz can tomato paste
3/4 C brown sugar
1/2 C vinegar
2 T prepared mustard
1 T salt
2 lbs beef back ribs

Mix water, ketchup, tomato paste, brown sugar, vinegar, mustard, and salt in a slow cooker, stirring to dissolve brown sugar and salt. Place short ribs into the sauce and stir to coat. Set cooker on Low, cover, and cook for eight hours.