Using a 1/2-inch melon baller, scoop out 30 watermelon and 30 cantaloupe balls. Set aside in separate bowls.
Add the simple syrup, honeydew melon and lemon juice into a blender. Puree until liquefied. Add 3 watermelon balls and 3 cantaloupe balls into each Zipzicle pouch. Pour the honeydew mixture into each pouch up to the indicated fill line. Seal closed and freeze for a minimum of 8 hours or overnight.