Pops are a 5:1 ratio. The colder and more carbonated your water the less syrup you'll use. Start with aprx 150ml or 4 pumps for a 1L bottle and adjust +/- from there. Experiment with the number of pumps to find the amount that suits your taste.
Cranberry Cocktail Syrup
Cranberry Cocktail Syrup is a staple and one of the most popular juices along with bar lime.