Mix all ingredients together in a large measuring cup except for the pieces of grapefruit.
Place one slice of grapefruit into each of your popsicle molds. Then pour your grapefruit liquid evenly into the popsicle mold over the grapefruit slices.
Place your popsicle mold in the freezer for about 30 minutes then add in your popsicle sticks. Freeze for an additional 3 hours or overnight.