Measure sugar and set aside. Do not reduce amount of sugar. Stir fruit pectin into juice and water, using a large pot, as the pot must not be more than 1/3 full to allow for a full rolling boil (a boil that cannot be stirred down). Bring to a full boil over high heat, stirring constantly. At once stir in sugar. Stir and bring to a full rolling boil, boil hard for 1 minute, stirring constantly with a wooden spoon. Remove from heat. Skim off foam with metal spoon. Immediately ladle into hot pint jars, leaving 1/8 inch space at the top of the jars. Wipe any spills from rims and threads of jars with a damp cloth. Quickly seal the jars by covering with hot lids. Screw bands on firmly. Let jelly stand to cool. Check seals, store in cool, dry place.